Skip to Main Navigation
Skip to Page Content
Share This:
https://ntp.niehs.nih.gov/go/4552

TDMS Study 05185-03 Pathology Tables

NTP                                        STATISTICAL ANALYSIS OF PRIMARY TUMORS                              REPORT: PEIRPT08     
LAB: IITRI                                               ISOBUTYL NITRITE (IBN)                                DATE: 05/20/95       
EXPERIMENT: 05185 TEST: 03                                                                                     TIME: 11:03:10       
TEST TYPE:  CHRONIC                             CAGES FROM 0000 TO LAST CAGE                                   PAGE:       1        
CONT: N01 ES 65143                              ROUTE: RESPIRATORY EXPOSURE WHOLE BODY                         NTP C#: 61052B       
PATHOLOGIST: RICHARD LONG                                                                                      CAS: 542-56-3        
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
               REASONS FOR REMOVAL:    ALL                                                                                          
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
               REMOVAL DATE RANGE:     ALL                                                                                          
                                                                                                                                    
               TREATMENT GROUPS:       INCLUDE ALL                                                                                  
NTP                                        STATISTICAL ANALYSIS OF PRIMARY TUMORS                              REPORT: PEIRPT08     
LAB: IITRI                                               ISOBUTYL NITRITE (IBN)                                DATE: 05/20/95       
EXPERIMENT: 05185 TEST: 03                                                                                     TIME: 11:03:10       
TEST TYPE:  CHRONIC                             CAGES FROM 0000 TO LAST CAGE                                                        
CONT: N01 ES 65143                              ROUTE: RESPIRATORY EXPOSURE WHOLE BODY                         NTP C#: 61052B       
PATHOLOGIST: RICHARD LONG                                                                                      CAS: 542-56-3        


                                                    RATS(FISCHER344)
                                              ----------------------------
             FOR ALL DOSES THE TUMOR RATES IN THE FOLLOWING TISSUES/ORGANS ARE BASED ON NUMBER OF TISSUES EXAMINED.
             IN OTHER TISSUES/ORGANS, RATES ARE BASED ON NUMBER OF ANIMALS NECROPSIED.
                                                                    
                                                    ----------------
                                                    Adrenal Cortex
                                                    Adrenal Medulla
                                                    Bone Marrow
                                                    Brain
                                                    Clitoral Gland
                                                    Clitoral/Preputial Gland
                                                    Epididymis
                                                    Heart
                                                    Islets, Pancreatic
                                                    Kidney
                                                    Larynx
                                                    Liver
                                                    Lung
                                                    Nose
                                                    Ovary
                                                    Pancreas
                                                    Parathyroid Gland
                                                    Pituitary Gland
                                                    Preputial Gland
                                                    Prostate
                                                    Salivary Glands
                                                    Spleen
                                                    Testes
                                                    Thymus
                                                    Thyroid Gland
                                                    Urinary Bladder
NTP                                        STATISTICAL ANALYSIS OF PRIMARY TUMORS                              REPORT: PEIRPT08     
LAB: IITRI                                               ISOBUTYL NITRITE (IBN)                                DATE: 05/20/95       
EXPERIMENT: 05185 TEST: 03                                                                                     TIME: 11:03:10       
TEST TYPE:  CHRONIC                             CAGES FROM 0000 TO LAST CAGE                                                        
CONT: N01 ES 65143                              ROUTE: RESPIRATORY EXPOSURE WHOLE BODY                         NTP C#: 61052B       
PATHOLOGIST: RICHARD LONG                                                                                      CAS: 542-56-3        


                                     SUMMARY OF STATISTICALLY SIGNIFICANT (P<=.05) RESULTS
                                     IN THE ANALYSIS OF THE STUDY OF ISOBUTYL NITRITE (IBN)
              ====================================================================================================
                                                           MALE RATS
                                                          -------------
                  ORGAN                               MORPHOLOGY
                 -------                             ------------
              Adrenal Medulla               Pheochromocytoma Benign
              Lung                          Alveolar/Bronchiolar Adenoma
                                            Alveolar/Bronchiolar Carcinoma
                                            Alveolar/Bronchiolar Carcinoma or Alveolar/Bronchiolar Adenoma
              Pituitary Gland: Pars Distalis or Unspecified Site
                                            Adenoma
                                            Carcinoma or Adenoma
              Testes                        Adenoma
              Zymbal's Gland                Carcinoma
              All Organs                    Leukemia: Lymphocytic, Monocytic, Mononuclear, or Undifferentiated
                                            Benign Tumors
                                            Malignant Tumors
                                            Malignant and Benign Tumors
              ====================================================================================================
                                                           FEMALE RATS
                                                          -------------
                  ORGAN                               MORPHOLOGY
                 -------                             ------------
              Lung                          Alveolar/Bronchiolar Adenoma
                                            Alveolar/Bronchiolar Carcinoma or Alveolar/Bronchiolar Adenoma
              Pituitary Gland: Pars Distalis or Unspecified Site
                                            Adenoma
                                            Carcinoma or Adenoma
              Thyroid Gland: Follicular Cell
                                            Carcinoma
              All Organs                    Leukemia: Lymphocytic, Monocytic, Mononuclear, or Undifferentiated
                                            Malignant Tumors
                                            Malignant and Benign Tumors
              ====================================================================================================
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE   1
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Adrenal Medulla                                                                                                                  |
|     Pheochromocytoma Benign                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  8/54 (15%)   8/55 (15%)   8/56 (14%)  15/56 (27%) |  0/55 (0%)    3/55 (5%)    1/55 (2%)    2/56 (4%)  |
|ADJUSTED (b)           |  37.0%        30.0%        20.9%        45.0%      |   0.0%         8.0%         2.8%         6.1%      |
|INTERIM SACRIFICE 1 (c)|  0/9 (0%)     0/10 (0%)    1/10 (10%)   0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  5/17 (29%)   6/23 (26%)   7/36 (19%)  10/28 (36%) |  0/29 (0%)    2/35 (6%)    0/31 (0%)    2/33 (6%)  |
|FIRST INCIDENCE (DAYS) |   639          576          456 (I)      564       |   ---          645          686          733 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.211      P=0.376N     P=0.128N     P=0.419    |  P=0.354      P=0.152      P=0.523      P=0.267    |
|INCIDENTAL TUMOR       |  P=0.089      P=0.470N     P=0.275N     P=0.163    |  P=0.277      P=0.129      P=0.477      P=0.267    |
|LOGISTIC REGRESSION    |  P=0.092      P=0.467N     P=0.373N     P=0.236    |  P=0.336      P=0.129      P=0.501      P=0.267    |
|COCHRAN-ARMITAGE       |  P=0.047 *                                         |  P=0.346                                           |
|FISHER EXACT           |               P=0.591N     P=0.575N     P=0.095    |               P=0.122      P=0.500      P=0.252    |
|=================================================================================================================================|
|                                                                                                                                 |
|Adrenal Medulla                                                                                                                  |
|     Pheochromocytoma Complex                                                                                                    |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/54 (0%)    0/55 (0%)    0/56 (0%)    0/56 (0%)  |  2/55 (4%)    0/55 (0%)    0/55 (0%)    0/56 (0%)  |
|ADJUSTED (b)           |   0.0%         0.0%         0.0%         0.0%      |   5.7%         0.0%         0.0%         0.0%      |
|INTERIM SACRIFICE 1 (c)|  0/9 (0%)     0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    0/23 (0%)    0/36 (0%)    0/28 (0%)  |  1/29 (3%)    0/35 (0%)    0/31 (0%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   ---          ---          ---          ---       |   602          ---          ---          ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |    (e)          (e)          (e)          (e)      |  P=0.114N     P=0.219N     P=0.232N     P=0.231N   |
|INCIDENTAL TUMOR       |    (e)          (e)          (e)          (e)      |  P=0.112N     P=0.350N     P=0.263N     P=0.226N   |
|LOGISTIC REGRESSION    |    (e)          (e)          (e)          (e)      |  P=0.115N     P=0.236N     P=0.238N     P=0.236N   |
|COCHRAN-ARMITAGE       |    (e)                                             |  P=0.115N                                          |
|FISHER EXACT           |                 (e)          (e)          (e)      |               P=0.248N     P=0.248N     P=0.243N   |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE   2
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Adrenal Medulla                                                                                                                  |
|     Pheochromocytoma Malignant                                                                                                  |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/54 (2%)    4/55 (7%)    0/56 (0%)    1/56 (2%)  |  0/55 (0%)    1/55 (2%)    0/55 (0%)    0/56 (0%)  |
|ADJUSTED (b)           |   5.9%        16.0%         0.0%         3.6%      |   0.0%         2.7%         0.0%         0.0%      |
|INTERIM SACRIFICE 1 (c)|  0/9 (0%)     0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  1/17 (6%)    2/23 (9%)    0/36 (0%)    1/28 (4%)  |  0/29 (0%)    0/35 (0%)    0/31 (0%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   729 (T)      718          ---          729 (T)   |   ---          720          ---          ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.188N     P=0.284      P=0.350N     P=0.647N   |  P=0.564N     P=0.535        (e)          (e)      |
|INCIDENTAL TUMOR       |  P=0.297N     P=0.272      P=0.350N     P=0.647N   |  P=0.675N     P=0.450        (e)          (e)      |
|LOGISTIC REGRESSION    |  P=0.198N     P=0.280      P=0.350N     P=0.647N   |  P=0.565N     P=0.519        (e)          (e)      |
|COCHRAN-ARMITAGE       |  P=0.322N                                          |  P=0.562N                                          |
|FISHER EXACT           |               P=0.187      P=0.491N     P=0.743N   |               P=0.500        (e)          (e)      |
|=================================================================================================================================|
|                                                                                                                                 |
|Adrenal Medulla                                                                                                                  |
|     Pheochromocytoma: Benign, Complex, Malignant, NOS                                                                           |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  8/54 (15%)  11/55 (20%)   8/56 (14%)  16/56 (29%) |  2/55 (4%)    4/55 (7%)    1/55 (2%)    2/56 (4%)  |
|ADJUSTED (b)           |  37.0%        39.4%        20.9%        48.1%      |   5.7%        10.4%         2.8%         6.1%      |
|INTERIM SACRIFICE 1 (c)|  0/9 (0%)     0/10 (0%)    1/10 (10%)   0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  5/17 (29%)   7/23 (30%)   7/36 (19%)  11/28 (39%) |  1/29 (3%)    2/35 (6%)    0/31 (0%)    2/33 (6%)  |
|FIRST INCIDENCE (DAYS) |   639          576          456 (I)      564       |   602          645          686          733 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.260      P=0.560      P=0.128N     P=0.351    |  P=0.415N     P=0.405      P=0.479N     P=0.663N   |
|INCIDENTAL TUMOR       |  P=0.092      P=0.463      P=0.275N     P=0.123    |  P=0.494N     P=0.249      P=0.539N     P=0.659N   |
|LOGISTIC REGRESSION    |  P=0.112      P=0.465      P=0.373N     P=0.179    |  P=0.432N     P=0.354      P=0.500N     P=0.691N   |
|COCHRAN-ARMITAGE       |  P=0.055                                           |  P=0.421N                                          |
|FISHER EXACT           |               P=0.323      P=0.575N     P=0.064    |               P=0.339      P=0.500N     P=0.684N   |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE   3
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Clitoral/Preputial Gland                                                                                                         |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  3/54 (6%)    5/56 (9%)    3/56 (5%)    2/56 (4%)  |  1/54 (2%)    1/54 (2%)    2/54 (4%)    1/56 (2%)  |
|ADJUSTED (b)           |  11.7%        15.4%         8.3%         5.3%      |   3.4%         2.9%         6.5%         2.9%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    1/10 (10%) |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  1/16 (6%)    1/23 (4%)    3/36 (8%)    1/28 (4%)  |  1/29 (3%)    1/35 (3%)    2/31 (6%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   583          551          729 (T)      456 (I)   |   733 (T)      733 (T)      733 (T)      696       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.164N     P=0.490      P=0.373N     P=0.380N   |  P=0.612      P=0.720N     P=0.523      P=0.736N   |
|INCIDENTAL TUMOR       |  P=0.278N     P=0.309      P=0.613N     P=0.437N   |  P=0.573      P=0.720N     P=0.523      P=0.703    |
|LOGISTIC REGRESSION    |  P=0.258N     P=0.259      P=0.546N     P=0.489N   |  P=0.598      P=0.720N     P=0.523      P=0.754N   |
|COCHRAN-ARMITAGE       |  P=0.282N                                          |  P=0.602                                           |
|FISHER EXACT           |               P=0.379      P=0.643N     P=0.483N   |               P=0.752N     P=0.500      P=0.743N   |
|=================================================================================================================================|
|                                                                                                                                 |
|Clitoral/Preputial Gland                                                                                                         |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  3/54 (6%)    5/56 (9%)    4/56 (7%)    2/56 (4%)  |  2/54 (4%)    1/54 (2%)    2/54 (4%)    1/56 (2%)  |
|ADJUSTED (b)           |  11.7%        15.4%        10.6%         5.3%      |   5.7%         2.9%         6.5%         2.9%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    1/10 (10%) |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  1/16 (6%)    1/23 (4%)    3/36 (8%)    1/28 (4%)  |  1/29 (3%)    1/35 (3%)    2/31 (6%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   583          551          684          456 (I)   |   602          733 (T)      733 (T)      696       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.176N     P=0.490      P=0.492N     P=0.380N   |  P=0.428N     P=0.457N     P=0.676N     P=0.480N   |
|INCIDENTAL TUMOR       |  P=0.324N     P=0.309      P=0.504      P=0.437N   |  P=0.444N     P=0.601N     P=0.687      P=0.563N   |
|LOGISTIC REGRESSION    |  P=0.276N     P=0.259      P=0.634      P=0.489N   |  P=0.441N     P=0.488N     P=0.692N     P=0.490N   |
|COCHRAN-ARMITAGE       |  P=0.304N                                          |  P=0.432N                                          |
|FISHER EXACT           |               P=0.379      P=0.520      P=0.483N   |               P=0.500N     P=0.691N     P=0.486N   |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE   4
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Islets, Pancreatic                                                                                                               |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  3/8 (38%)    6/9 (67%)    2/5 (40%)    4/5 (80%)  |  5/6 (83%)    1/1 (100%)   0/0 (0%)     1/1 (100%) |
|ADJUSTED (b)           |  41.6%        59.4%        26.8%        75.8%      | 100.0%       100.0%         0.0%       100.0%      |
|INTERIM SACRIFICE 1 (c)|  0/0          0/0          0/0          0/0        |  0/0          0/0          0/0          0/0        |
|TERMINAL (d)           |  2/5 (40%)    4/7 (57%)    1/4 (25%)    3/4 (75%)  |  3/3 (100%)   1/1 (100%)   0/0          1/1 (100%) |
|FIRST INCIDENCE (DAYS) |   583          551          667          722       |   516          733 (T)      ---          733 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.492      P=0.370      P=0.494N     P=0.452    |  P=0.122N     P=0.237N     P=0.242N     P=0.253N   |
|INCIDENTAL TUMOR       |  P=0.270      P=0.312      P=0.588N     P=0.362    |    (e)          (e)          (e)          (e)      |
|LOGISTIC REGRESSION    |  P=0.120      P=0.205      P=0.643      P=0.213    |    (e)          (e)          (e)          (e)      |
|COCHRAN-ARMITAGE       |  P=0.179                                           |  P=0.620                                           |
|FISHER EXACT           |               P=0.238      P=0.685      P=0.179    |               P=0.857      P=1.000N     P=0.857    |
|=================================================================================================================================|
|                                                                                                                                 |
|Islets, Pancreatic                                                                                                               |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  4/8 (50%)    6/9 (67%)    3/5 (60%)    4/5 (80%)  |  5/6 (83%)    1/1 (100%)   0/0 (0%)     1/1 (100%) |
|ADJUSTED (b)           |  43.2%        59.4%        51.2%        75.8%      | 100.0%       100.0%         0.0%       100.0%      |
|INTERIM SACRIFICE 1 (c)|  0/0          0/0          0/0          0/0        |  0/0          0/0          0/0          0/0        |
|TERMINAL (d)           |  2/5 (40%)    4/7 (57%)    2/4 (50%)    3/4 (75%)  |  3/3 (100%)   1/1 (100%)   0/0          1/1 (100%) |
|FIRST INCIDENCE (DAYS) |   583          551          667          722       |   516          733 (T)      ---          733 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.567N     P=0.530      P=0.503N     P=0.626    |  P=0.122N     P=0.237N     P=0.242N     P=0.253N   |
|INCIDENTAL TUMOR       |  P=0.248      P=0.400      P=0.638      P=0.362    |    (e)          (e)          (e)          (e)      |
|LOGISTIC REGRESSION    |  P=0.132      P=0.322      P=0.461      P=0.225    |    (e)          (e)          (e)          (e)      |
|COCHRAN-ARMITAGE       |  P=0.243                                           |  P=0.620                                           |
|FISHER EXACT           |               P=0.419      P=0.587      P=0.315    |               P=0.857      P=1.000N     P=0.857    |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE   5
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Adenoma                                                                                                |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/56 (0%)    4/56 (7%)   13/56 (23%)  14/56 (25%) |  0/56 (0%)    2/55 (4%)    2/56 (4%)   10/56 (18%) |
|ADJUSTED (b)           |   0.0%        14.7%        33.4%        45.8%      |   0.0%         5.2%         5.8%        29.1%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    1/10 (10%)   1/10 (10%)   1/10 (10%) |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    3/23 (13%)  11/36 (31%)  12/28 (43%) |  0/29 (0%)    1/35 (3%)    1/31 (3%)    9/33 (27%) |
|FIRST INCIDENCE (DAYS) |   ---          456 (I)      456 (I)      456 (I)   |   ---          648          653          622       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P<0.001 **   P=0.095      P=0.005 **   P=0.001 ** |  P<0.001 **   P=0.272      P=0.253      P=0.002 ** |
|INCIDENTAL TUMOR       |  P<0.001 **   P=0.095      P=0.002 **   P<0.001 ** |  P<0.001 **   P=0.232      P=0.247      P=0.002 ** |
|LOGISTIC REGRESSION    |  P<0.001 **   P=0.070      P<0.001 **   P<0.001 ** |  P<0.001 **   P=0.241      P=0.240      P=0.001 ** |
|COCHRAN-ARMITAGE       |  P<0.001 **                                        |  P<0.001 **                                        |
|FISHER EXACT           |               P=0.059      P<0.001 **   P<0.001 ** |               P=0.243      P=0.248      P<0.001 ** |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Carcinoma                                                                                              |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/56 (2%)    2/56 (4%)    1/56 (2%)    6/56 (11%) |  0/56 (0%)    1/55 (2%)    0/56 (0%)    1/56 (2%)  |
|ADJUSTED (b)           |   1.8%         7.2%         2.8%        18.1%      |   0.0%         2.4%         0.0%         3.0%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    1/23 (4%)    1/36 (3%)    3/28 (11%) |  0/29 (0%)    0/35 (0%)    0/31 (0%)    1/33 (3%)  |
|FIRST INCIDENCE (DAYS) |   415          663          729 (T)      523       |   ---          645          ---          733 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.041 *    P=0.559      P=0.683N     P=0.138    |  P=0.407      P=0.520        (e)        P=0.526    |
|INCIDENTAL TUMOR       |  P=0.003 **   P=0.439      P=0.703      P=0.011 *  |  P=0.344      P=0.450        (e)        P=0.526    |
|LOGISTIC REGRESSION    |  P=0.021 *    P=0.489      P=0.741      P=0.062    |  P=0.404      P=0.495        (e)        P=0.526    |
|COCHRAN-ARMITAGE       |  P=0.019 *                                         |  P=0.408                                           |
|FISHER EXACT           |               P=0.500      P=0.752N     P=0.057    |               P=0.495        (e)        P=0.500    |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE   6
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Lung                                                                                                                             |
|     Alveolar/Bronchiolar Carcinoma or Alveolar/Bronchiolar Adenoma                                                              |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/56 (2%)    6/56 (11%)  14/56 (25%)  16/56 (29%) |  0/56 (0%)    3/55 (5%)    2/56 (4%)   11/56 (20%) |
|ADJUSTED (b)           |   1.8%        21.3%        36.1%        48.5%      |   0.0%         7.5%         5.8%        32.1%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    1/10 (10%)   1/10 (10%)   1/10 (10%) |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    4/23 (17%)  12/36 (33%)  12/28 (43%) |  0/29 (0%)    1/35 (3%)    1/31 (3%)   10/33 (30%) |
|FIRST INCIDENCE (DAYS) |   415          456 (I)      456 (I)      456 (I)   |   ---          645          653          622       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P<0.001 **   P=0.100      P=0.012 *    P=0.002 ** |  P<0.001 **   P=0.148      P=0.253      P=0.001 ** |
|INCIDENTAL TUMOR       |  P<0.001 **   P=0.065      P=0.003 **   P<0.001 ** |  P<0.001 **   P=0.100      P=0.247      P=0.001 ** |
|LOGISTIC REGRESSION    |  P<0.001 **   P=0.060      P=0.001 **   P<0.001 ** |  P<0.001 **   P=0.120      P=0.240      P<0.001 ** |
|COCHRAN-ARMITAGE       |  P<0.001 **                                        |  P<0.001 **                                        |
|FISHER EXACT           |               P=0.057      P<0.001 **   P<0.001 ** |               P=0.118      P=0.248      P<0.001 ** |
|=================================================================================================================================|
|                                                                                                                                 |
|Mammary Gland                                                                                                                    |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/56 (0%)    0/56 (0%)    0/56 (0%)    0/56 (0%)  |  3/56 (5%)    1/55 (2%)    1/56 (2%)    1/56 (2%)  |
|ADJUSTED (b)           |   0.0%         0.0%         0.0%         0.0%      |   9.3%         2.9%         3.2%         3.0%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    0/23 (0%)    0/36 (0%)    0/28 (0%)  |  2/29 (7%)    1/35 (3%)    1/31 (3%)    1/33 (3%)  |
|FIRST INCIDENCE (DAYS) |   ---          ---          ---          ---       |   641          733 (T)      733 (T)      733 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |    (e)          (e)          (e)          (e)      |  P=0.228N     P=0.252N     P=0.286N     P=0.277N   |
|INCIDENTAL TUMOR       |    (e)          (e)          (e)          (e)      |  P=0.229N     P=0.370N     P=0.332N     P=0.291N   |
|LOGISTIC REGRESSION    |    (e)          (e)          (e)          (e)      |  P=0.242N     P=0.284N     P=0.294N     P=0.301N   |
|COCHRAN-ARMITAGE       |    (e)                                             |  P=0.242N                                          |
|FISHER EXACT           |                 (e)          (e)          (e)      |               P=0.316N     P=0.309N     P=0.309N   |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE   7
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Mammary Gland                                                                                                                    |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/56 (0%)    0/56 (0%)    0/56 (0%)    0/56 (0%)  |  3/56 (5%)    2/55 (4%)    1/56 (2%)    2/56 (4%)  |
|ADJUSTED (b)           |   0.0%         0.0%         0.0%         0.0%      |   9.3%         5.7%         3.2%         5.5%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    0/23 (0%)    0/36 (0%)    0/28 (0%)  |  2/29 (7%)    2/35 (6%)    1/31 (3%)    1/33 (3%)  |
|FIRST INCIDENCE (DAYS) |   ---          ---          ---          ---       |   641          733 (T)      733 (T)      622       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |    (e)          (e)          (e)          (e)      |  P=0.389N     P=0.425N     P=0.286N     P=0.474N   |
|INCIDENTAL TUMOR       |    (e)          (e)          (e)          (e)      |  P=0.381N     P=0.556N     P=0.332N     P=0.505N   |
|LOGISTIC REGRESSION    |    (e)          (e)          (e)          (e)      |  P=0.408N     P=0.468N     P=0.294N     P=0.502N   |
|COCHRAN-ARMITAGE       |    (e)                                             |  P=0.402N                                          |
|FISHER EXACT           |                 (e)          (e)          (e)      |               P=0.509N     P=0.309N     P=0.500N   |
|=================================================================================================================================|
|                                                                                                                                 |
|Mammary Gland                                                                                                                    |
|     Fibroadenoma                                                                                                                |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/56 (0%)    2/56 (4%)    1/56 (2%)    0/56 (0%)  | 12/56 (21%)  14/55 (25%)  20/56 (36%)  13/56 (23%) |
|ADJUSTED (b)           |   0.0%         8.7%         2.8%         0.0%      |  34.6%        35.7%        52.0%        34.8%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  1/10 (10%)   0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    2/23 (9%)    1/36 (3%)    0/28 (0%)  |  8/29 (28%)  10/35 (29%)  13/31 (42%)   9/33 (27%) |
|FIRST INCIDENCE (DAYS) |   ---          729 (T)      729 (T)      ---       |   457 (I)      645          610          622       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.340N     P=0.306      P=0.650        (e)      |  P=0.495      P=0.571N     P=0.117      P=0.572N   |
|INCIDENTAL TUMOR       |  P=0.340N     P=0.306      P=0.650        (e)      |  P=0.299      P=0.482      P=0.070      P=0.403    |
|LOGISTIC REGRESSION    |  P=0.340N     P=0.306      P=0.650        (e)      |  P=0.337      P=0.463      P=0.071      P=0.496    |
|COCHRAN-ARMITAGE       |  P=0.458N                                          |  P=0.437                                           |
|FISHER EXACT           |               P=0.248      P=0.500        (e)      |               P=0.391      P=0.071      P=0.500    |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE   8
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Mammary Gland                                                                                                                    |
|     Fibroma, Fibroadenoma or Adenoma                                                                                            |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/56 (0%)    2/56 (4%)    1/56 (2%)    0/56 (0%)  | 12/56 (21%)  15/55 (27%)  20/56 (36%)  13/56 (23%) |
|ADJUSTED (b)           |   0.0%         8.7%         2.8%         0.0%      |  34.6%        38.3%        52.0%        34.8%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  1/10 (10%)   0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    2/23 (9%)    1/36 (3%)    0/28 (0%)  |  8/29 (28%)  11/35 (31%)  13/31 (42%)   9/33 (27%) |
|FIRST INCIDENCE (DAYS) |   ---          729 (T)      729 (T)      ---       |   457 (I)      645          610          622       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.340N     P=0.306      P=0.650        (e)      |  P=0.527      P=0.523      P=0.117      P=0.572N   |
|INCIDENTAL TUMOR       |  P=0.340N     P=0.306      P=0.650        (e)      |  P=0.330      P=0.400      P=0.070      P=0.403    |
|LOGISTIC REGRESSION    |  P=0.340N     P=0.306      P=0.650        (e)      |  P=0.369      P=0.379      P=0.071      P=0.496    |
|COCHRAN-ARMITAGE       |  P=0.458N                                          |  P=0.468                                           |
|FISHER EXACT           |               P=0.248      P=0.500        (e)      |               P=0.310      P=0.071      P=0.500    |
|=================================================================================================================================|
|                                                                                                                                 |
|Mammary Gland                                                                                                                    |
|     Fibroma, Fibroadenoma, Carcinoma, or Adenoma                                                                                |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/56 (0%)    2/56 (4%)    1/56 (2%)    0/56 (0%)  | 14/56 (25%)  15/55 (27%)  21/56 (38%)  14/56 (25%) |
|ADJUSTED (b)           |   0.0%         8.7%         2.8%         0.0%      |  39.3%        38.3%        54.7%        37.6%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  1/10 (10%)   0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    2/23 (9%)    1/36 (3%)    0/28 (0%)  |  9/29 (31%)  11/35 (31%)  14/31 (45%)  10/33 (30%) |
|FIRST INCIDENCE (DAYS) |   ---          729 (T)      729 (T)      ---       |   457 (I)      645          610          622       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.340N     P=0.306      P=0.650        (e)      |  P=0.510N     P=0.467N     P=0.172      P=0.476N   |
|INCIDENTAL TUMOR       |  P=0.340N     P=0.306      P=0.650        (e)      |  P=0.378      P=0.530      P=0.102      P=0.497    |
|LOGISTIC REGRESSION    |  P=0.340N     P=0.306      P=0.650        (e)      |  P=0.405      P=0.558      P=0.112      P=0.584    |
|COCHRAN-ARMITAGE       |  P=0.458N                                          |  P=0.508                                           |
|FISHER EXACT           |               P=0.248      P=0.500        (e)      |               P=0.477      P=0.111      P=0.586N   |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE   9
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Oral Cavity (Oral Mucosa, Tongue, Pharynx, Tooth, Gingiva)                                                                       |
|     Squamous Cell Carcinoma, Papilloma Squamous, or Papilloma                                                                   |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/56 (0%)    1/56 (2%)    0/56 (0%)    0/56 (0%)  |  1/56 (2%)    1/55 (2%)    2/56 (4%)    1/56 (2%)  |
|ADJUSTED (b)           |   0.0%         4.3%         0.0%         0.0%      |   2.2%         2.9%         6.5%         2.5%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    1/23 (4%)    0/36 (0%)    0/28 (0%)  |  0/29 (0%)    1/35 (3%)    2/31 (6%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   ---          729 (T)      ---          ---       |   516          733 (T)      733 (T)      617       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.500N     P=0.560        (e)          (e)      |  P=0.597      P=0.745N     P=0.510      P=0.750    |
|INCIDENTAL TUMOR       |  P=0.500N     P=0.560        (e)          (e)      |  P=0.599N     P=0.739      P=0.469      P=0.755N   |
|LOGISTIC REGRESSION    |  P=0.500N     P=0.560        (e)          (e)      |  P=0.589      P=0.754      P=0.500      P=0.743N   |
|COCHRAN-ARMITAGE       |  P=0.565N                                          |  P=0.592                                           |
|FISHER EXACT           |               P=0.500        (e)          (e)      |               P=0.748      P=0.500      P=0.752N   |
|=================================================================================================================================|
|                                                                                                                                 |
|Pituitary Gland: Pars Distalis or Unspecified Site                                                                               |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 30/55 (55%)  25/56 (45%)  30/56 (54%)  30/55 (55%) | 26/56 (46%)  16/53 (30%)  20/55 (36%)  18/56 (32%) |
|ADJUSTED (b)           |  75.3%        71.7%        62.9%        73.5%      |  65.4%        42.0%        53.1%        45.7%      |
|INTERIM SACRIFICE 1 (c)|  5/10 (50%)   1/10 (10%)   5/10 (50%)   3/10 (30%) |  1/10 (10%)   1/10 (10%)   0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  8/16 (50%)  14/23 (61%)  19/36 (53%)  17/27 (63%) | 16/29 (55%)  12/33 (36%)  13/30 (43%)  12/33 (36%) |
|FIRST INCIDENCE (DAYS) |   427          456 (I)      456 (I)      456 (I)   |   457 (I)      457 (I)      604          483       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.126N     P=0.043N*    P=0.016N*    P=0.095N   |  P=0.115N     P=0.019N*    P=0.149N     P=0.058N   |
|INCIDENTAL TUMOR       |  P=0.391      P=0.161N     P=0.474      P=0.557N   |  P=0.161N     P=0.076N     P=0.217N     P=0.101N   |
|LOGISTIC REGRESSION    |  P=0.478      P=0.141N     P=0.497N     P=0.490N   |  P=0.183N     P=0.044N*    P=0.171N     P=0.088N   |
|COCHRAN-ARMITAGE       |  P=0.390                                           |  P=0.136N                                          |
|FISHER EXACT           |               P=0.197N     P=0.535N     P=0.576N   |               P=0.061N     P=0.189N     P=0.088N   |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE  10
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Pituitary Gland: Pars Distalis or Unspecified Site                                                                               |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 30/55 (55%)  25/56 (45%)  30/56 (54%)  30/55 (55%) | 27/56 (48%)  16/53 (30%)  21/55 (38%)  18/56 (32%) |
|ADJUSTED (b)           |  75.3%        71.7%        62.9%        73.5%      |  66.2%        42.0%        54.3%        45.7%      |
|INTERIM SACRIFICE 1 (c)|  5/10 (50%)   1/10 (10%)   5/10 (50%)   3/10 (30%) |  1/10 (10%)   1/10 (10%)   0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  8/16 (50%)  14/23 (61%)  19/36 (53%)  17/27 (63%) | 16/29 (55%)  12/33 (36%)  13/30 (43%)  12/33 (36%) |
|FIRST INCIDENCE (DAYS) |   427          456 (I)      456 (I)      456 (I)   |   457 (I)      457 (I)      604          483       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.126N     P=0.043N*    P=0.016N*    P=0.095N   |  P=0.095N     P=0.013N*    P=0.155N     P=0.043N*  |
|INCIDENTAL TUMOR       |  P=0.391      P=0.161N     P=0.474      P=0.557N   |  P=0.133N     P=0.065N     P=0.231N     P=0.073N   |
|LOGISTIC REGRESSION    |  P=0.478      P=0.141N     P=0.497N     P=0.490N   |  P=0.156N     P=0.030N*    P=0.237N     P=0.061N   |
|COCHRAN-ARMITAGE       |  P=0.390                                           |  P=0.109N                                          |
|FISHER EXACT           |               P=0.197N     P=0.535N     P=0.576N   |               P=0.042N*    P=0.191N     P=0.061N   |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Basal or Sq. Cell Carcinoma, Carcinoma, Basosq. Tumor (M or B), Basal                                                       |
|     Cell Adenoma, Adenoma, Papilloma, Sq Papilloma, Keratoacanthoma, Trichoepithelioma                                          |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  3/56 (5%)    4/56 (7%)    4/56 (7%)    1/56 (2%)  |  1/56 (2%)    1/55 (2%)    0/56 (0%)    1/56 (2%)  |
|ADJUSTED (b)           |  13.5%        13.6%        10.8%         3.3%      |   3.4%         2.7%         0.0%         2.5%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  1/17 (6%)    2/23 (9%)    3/36 (8%)    0/28 (0%)  |  1/29 (3%)    0/35 (0%)    0/31 (0%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   639          645          719          722       |   733 (T)      720          ---          617       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.092N     P=0.649N     P=0.462N     P=0.177N   |  P=0.613N     P=0.719N     P=0.487N     P=0.749N   |
|INCIDENTAL TUMOR       |  P=0.225N     P=0.584      P=0.519      P=0.358N   |  P=0.648      P=0.755      P=0.487N     P=0.751    |
|LOGISTIC REGRESSION    |  P=0.138N     P=0.571      P=0.619N     P=0.232N   |  P=0.619N     P=0.736N     P=0.487N     P=0.761    |
|COCHRAN-ARMITAGE       |  P=0.211N                                          |  P=0.614N                                          |
|FISHER EXACT           |               P=0.500      P=0.500      P=0.309N   |               P=0.748      P=0.500N     P=0.752N   |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE  11
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Fibroma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/56 (0%)    0/56 (0%)    1/56 (2%)    2/56 (4%)  |  0/56 (0%)    2/55 (4%)    0/56 (0%)    1/56 (2%)  |
|ADJUSTED (b)           |   0.0%         0.0%         2.8%         7.1%      |   0.0%         4.6%         0.0%         1.8%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    0/23 (0%)    1/36 (3%)    2/28 (7%)  |  0/29 (0%)    1/35 (3%)    0/31 (0%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   ---          ---          729 (T)      729 (T)   |   ---          378          ---          394       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.103        (e)        P=0.650      P=0.353    |  P=0.545      P=0.258        (e)        P=0.496    |
|INCIDENTAL TUMOR       |  P=0.103        (e)        P=0.650      P=0.353    |  P=0.619      P=0.214        (e)        P=0.557    |
|LOGISTIC REGRESSION    |  P=0.103        (e)        P=0.650      P=0.352    |  P=0.626      P=0.229        (e)        P=0.687    |
|COCHRAN-ARMITAGE       |  P=0.070                                           |  P=0.543                                           |
|FISHER EXACT           |                 (e)        P=0.500      P=0.248    |               P=0.243        (e)        P=0.500    |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Fibroma, Fibrosarcoma, Sarcoma, Myxoma, Myxosarcoma, or Fibrous Histiocytoma                                                |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/56 (2%)    0/56 (0%)    2/56 (4%)    2/56 (4%)  |  1/56 (2%)    2/55 (4%)    0/56 (0%)    1/56 (2%)  |
|ADJUSTED (b)           |   2.7%         0.0%         5.6%         7.1%      |   3.4%         4.6%         0.0%         1.8%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    0/23 (0%)    2/36 (6%)    2/28 (7%)  |  1/29 (3%)    1/35 (3%)    0/31 (0%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   611          ---          729 (T)      729 (T)   |   733 (T)      378          ---          394       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.341      P=0.490N     P=0.682      P=0.620    |  P=0.490N     P=0.541      P=0.487N     P=0.748N   |
|INCIDENTAL TUMOR       |  P=0.336      P=0.657N     P=0.538      P=0.591    |  P=0.423N     P=0.497      P=0.487N     P=0.714N   |
|LOGISTIC REGRESSION    |  P=0.294      P=0.505N     P=0.577      P=0.561    |  P=0.454N     P=0.486      P=0.487N     P=0.742N   |
|COCHRAN-ARMITAGE       |  P=0.244                                           |  P=0.496N                                          |
|FISHER EXACT           |               P=0.500N     P=0.500      P=0.500    |               P=0.493      P=0.500N     P=0.752N   |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE  12
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Keratoacanthoma                                                                                                             |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  2/56 (4%)    2/56 (4%)    2/56 (4%)    1/56 (2%)  |  0/56 (0%)    0/55 (0%)    0/56 (0%)    0/56 (0%)  |
|ADJUSTED (b)           |  10.8%         7.1%         5.6%         3.3%      |   0.0%         0.0%         0.0%         0.0%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  1/17 (6%)    1/23 (4%)    2/36 (6%)    0/28 (0%)  |  0/29 (0%)    0/35 (0%)    0/31 (0%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   695          651          729 (T)      722       |   ---          ---          ---          ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.225N     P=0.574N     P=0.410N     P=0.324N   |    (e)          (e)          (e)          (e)      |
|INCIDENTAL TUMOR       |  P=0.376N     P=0.580N     P=0.565N     P=0.548N   |    (e)          (e)          (e)          (e)      |
|LOGISTIC REGRESSION    |  P=0.280N     P=0.631N     P=0.498N     P=0.382N   |    (e)          (e)          (e)          (e)      |
|COCHRAN-ARMITAGE       |  P=0.373N                                          |    (e)                                             |
|FISHER EXACT           |               P=0.691N     P=0.691N     P=0.500N   |                 (e)          (e)          (e)      |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Squamous Cell Papilloma, Papilloma, Squamous Cell Carcinoma or Keratoacanthoma                                              |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  3/56 (5%)    3/56 (5%)    3/56 (5%)    1/56 (2%)  |  1/56 (2%)    1/55 (2%)    0/56 (0%)    1/56 (2%)  |
|ADJUSTED (b)           |  13.5%        11.3%         8.1%         3.3%      |   3.4%         2.7%         0.0%         2.5%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  1/17 (6%)    2/23 (9%)    2/36 (6%)    0/28 (0%)  |  1/29 (3%)    0/35 (0%)    0/31 (0%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   639          651          719          722       |   733 (T)      720          ---          617       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.103N     P=0.524N     P=0.352N     P=0.177N   |  P=0.613N     P=0.719N     P=0.487N     P=0.749N   |
|INCIDENTAL TUMOR       |  P=0.233N     P=0.604N     P=0.635      P=0.358N   |  P=0.648      P=0.755      P=0.487N     P=0.751    |
|LOGISTIC REGRESSION    |  P=0.147N     P=0.591N     P=0.500N     P=0.232N   |  P=0.619N     P=0.736N     P=0.487N     P=0.761    |
|COCHRAN-ARMITAGE       |  P=0.222N                                          |  P=0.614N                                          |
|FISHER EXACT           |               P=0.661N     P=0.661N     P=0.309N   |               P=0.748      P=0.500N     P=0.752N   |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE  13
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Skin                                                                                                                             |
|     Squamous Cell Papilloma, Papilloma, or Keratoacanthoma                                                                      |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  2/56 (4%)    2/56 (4%)    2/56 (4%)    1/56 (2%)  |  1/56 (2%)    1/55 (2%)    0/56 (0%)    1/56 (2%)  |
|ADJUSTED (b)           |  10.8%         7.1%         5.6%         3.3%      |   3.4%         2.7%         0.0%         2.5%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  1/17 (6%)    1/23 (4%)    2/36 (6%)    0/28 (0%)  |  1/29 (3%)    0/35 (0%)    0/31 (0%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   695          651          729 (T)      722       |   733 (T)      720          ---          617       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.225N     P=0.574N     P=0.410N     P=0.324N   |  P=0.613N     P=0.719N     P=0.487N     P=0.749N   |
|INCIDENTAL TUMOR       |  P=0.376N     P=0.580N     P=0.565N     P=0.548N   |  P=0.648      P=0.755      P=0.487N     P=0.751    |
|LOGISTIC REGRESSION    |  P=0.280N     P=0.631N     P=0.498N     P=0.382N   |  P=0.619N     P=0.736N     P=0.487N     P=0.761    |
|COCHRAN-ARMITAGE       |  P=0.373N                                          |  P=0.614N                                          |
|FISHER EXACT           |               P=0.691N     P=0.691N     P=0.500N   |               P=0.748      P=0.500N     P=0.752N   |
|=================================================================================================================================|
|                                                                                                                                 |
|Spleen                                                                                                                           |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/56 (2%)    1/55 (2%)    0/56 (0%)    2/55 (4%)  |  0/56 (0%)    0/55 (0%)    0/54 (0%)    1/56 (2%)  |
|ADJUSTED (b)           |   5.9%         4.3%         0.0%         6.9%      |   0.0%         0.0%         0.0%         3.0%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  1/17 (6%)    1/23 (4%)    0/36 (0%)    1/28 (4%)  |  0/29 (0%)    0/35 (0%)    0/31 (0%)    1/33 (3%)  |
|FIRST INCIDENCE (DAYS) |   729 (T)      729 (T)      ---          728       |   ---          ---          ---          733 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.497      P=0.694N     P=0.350N     P=0.674    |  P=0.205        (e)          (e)        P=0.526    |
|INCIDENTAL TUMOR       |  P=0.399      P=0.694N     P=0.350N     P=0.547    |  P=0.205        (e)          (e)        P=0.526    |
|LOGISTIC REGRESSION    |  P=0.504      P=0.694N     P=0.350N     P=0.683    |  P=0.205        (e)          (e)        P=0.526    |
|COCHRAN-ARMITAGE       |  P=0.363                                           |  P=0.200                                           |
|FISHER EXACT           |               P=0.748      P=0.500N     P=0.493    |                 (e)          (e)        P=0.500    |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE  14
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Testes                                                                                                                           |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 34/56 (61%)  34/56 (61%)  38/56 (68%)  39/56 (70%) |                                                    |
|ADJUSTED (b)           |  90.7%        81.7%        86.0%        84.0%      |                                                    |
|INTERIM SACRIFICE 1 (c)|  3/10 (30%)   6/10 (60%)   4/10 (40%)   8/10 (80%) |                                                    |
|TERMINAL (d)           | 14/17 (82%)  16/23 (70%)  30/36 (83%)  21/28 (75%) |                                                    |
|FIRST INCIDENCE (DAYS) |   427          456 (I)      456 (I)      456 (I)   |                                                    |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.165N     P=0.150N     P=0.006N**   P=0.182N   |                                                    |
|INCIDENTAL TUMOR       |  P=0.261      P=0.471N     P=0.534N     P=0.275    |                                                    |
|LOGISTIC REGRESSION    |  P=0.220      P=0.486N     P=0.518      P=0.291    |                                                    |
|COCHRAN-ARMITAGE       |  P=0.143                                           |                                                    |
|FISHER EXACT           |               P=0.577N     P=0.277      P=0.214    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Thyroid Gland: C-Cell                                                                                                            |
|     Adenoma                                                                                                                     |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/55 (2%)    1/56 (2%)    5/56 (9%)    4/56 (7%)  |  1/56 (2%)    4/55 (7%)    2/56 (4%)    3/56 (5%)  |
|ADJUSTED (b)           |   3.2%         1.9%        13.9%        13.7%      |   3.4%        11.4%         5.8%         9.1%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    1/10 (10%)   0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    0/23 (0%)    5/36 (14%)   3/28 (11%) |  1/29 (3%)    4/35 (11%)   1/31 (3%)    3/33 (9%)  |
|FIRST INCIDENCE (DAYS) |   640          456 (I)      729 (T)      722       |   733 (T)      733 (T)      674          733 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.161      P=0.738N     P=0.316      P=0.331    |  P=0.406      P=0.239      P=0.532      P=0.352    |
|INCIDENTAL TUMOR       |  P=0.128      P=0.677      P=0.206      P=0.230    |  P=0.371      P=0.239      P=0.515      P=0.352    |
|LOGISTIC REGRESSION    |  P=0.105      P=0.756      P=0.214      P=0.269    |  P=0.376      P=0.239      P=0.512      P=0.352    |
|COCHRAN-ARMITAGE       |  P=0.081                                           |  P=0.376                                           |
|FISHER EXACT           |               P=0.748N     P=0.107      P=0.187    |               P=0.176      P=0.500      P=0.309    |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE  15
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Thyroid Gland: C-Cell                                                                                                            |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/55 (2%)    0/56 (0%)    0/56 (0%)    1/56 (2%)  |  0/56 (0%)    2/55 (4%)    0/56 (0%)    0/56 (0%)  |
|ADJUSTED (b)           |   4.3%         0.0%         0.0%         3.6%      |   0.0%         5.7%         0.0%         0.0%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    0/23 (0%)    0/36 (0%)    1/28 (4%)  |  0/29 (0%)    2/35 (6%)    0/31 (0%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   667          ---          ---          729 (T)   |   ---          733 (T)      ---          ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.675      P=0.428N     P=0.385N     P=0.658N   |  P=0.387N     P=0.280        (e)          (e)      |
|INCIDENTAL TUMOR       |  P=0.576      P=0.438N     P=0.657N     P=0.761N   |  P=0.387N     P=0.280        (e)          (e)      |
|LOGISTIC REGRESSION    |  P=0.630      P=0.484N     P=0.478N     P=0.717N   |  P=0.387N     P=0.280        (e)          (e)      |
|COCHRAN-ARMITAGE       |  P=0.597                                           |  P=0.400N                                          |
|FISHER EXACT           |               P=0.495N     P=0.495N     P=0.748N   |               P=0.243        (e)          (e)      |
|=================================================================================================================================|
|                                                                                                                                 |
|Thyroid Gland: C-Cell                                                                                                            |
|     Carcinoma or Adenoma                                                                                                        |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  2/55 (4%)    1/56 (2%)    5/56 (9%)    5/56 (9%)  |  1/56 (2%)    5/55 (9%)    2/56 (4%)    3/56 (5%)  |
|ADJUSTED (b)           |   7.4%         1.9%        13.9%        17.1%      |   3.4%        14.3%         5.8%         9.1%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    1/10 (10%)   0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    0/23 (0%)    5/36 (14%)   4/28 (14%) |  1/29 (3%)    5/35 (14%)   1/31 (3%)    3/33 (9%)  |
|FIRST INCIDENCE (DAYS) |   640          456 (I)      729 (T)      722       |   733 (T)      733 (T)      674          733 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.175      P=0.435N     P=0.535      P=0.421    |  P=0.477      P=0.149      P=0.532      P=0.352    |
|INCIDENTAL TUMOR       |  P=0.120      P=0.552N     P=0.312      P=0.266    |  P=0.443      P=0.149      P=0.515      P=0.352    |
|LOGISTIC REGRESSION    |  P=0.111      P=0.507N     P=0.369      P=0.328    |  P=0.446      P=0.149      P=0.512      P=0.352    |
|COCHRAN-ARMITAGE       |  P=0.083                                           |  P=0.443                                           |
|FISHER EXACT           |               P=0.493N     P=0.226      P=0.226    |               P=0.099      P=0.500      P=0.309    |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE  16
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Thyroid Gland: Follicular Cell                                                                                                   |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |                                                    |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/55 (2%)    1/56 (2%)    2/56 (4%)    1/56 (2%)  |  0/56 (0%)    0/55 (0%)    0/56 (0%)    2/56 (4%)  |
|ADJUSTED (b)           |   5.9%         2.9%         5.1%         3.4%      |   0.0%         0.0%         0.0%         6.1%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  1/17 (6%)    0/23 (0%)    1/36 (3%)    0/28 (0%)  |  0/29 (0%)    0/35 (0%)    0/31 (0%)    2/33 (6%)  |
|FIRST INCIDENCE (DAYS) |   729 (T)      651          631          728       |   ---          ---          ---          733 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.550N     P=0.701N     P=0.692      P=0.641N   |  P=0.049 *      (e)          (e)        P=0.267    |
|INCIDENTAL TUMOR       |  P=0.554      P=0.691N     P=0.538      P=0.761N   |  P=0.049 *      (e)          (e)        P=0.267    |
|LOGISTIC REGRESSION    |  P=0.604N     P=0.733N     P=0.593      P=0.641N   |  P=0.049 *      (e)          (e)        P=0.267    |
|COCHRAN-ARMITAGE       |  P=0.595                                           |  P=0.047 *                                         |
|FISHER EXACT           |               P=0.748N     P=0.507      P=0.748N   |                 (e)          (e)        P=0.248    |
|=================================================================================================================================|
|                                                                                                                                 |
|Tongue                                                                                                                           |
|     Squamous Cell Carcinoma or Papilloma Squamous                                                                               |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/56 (0%)    1/56 (2%)    0/56 (0%)    0/56 (0%)  |  1/56 (2%)    1/55 (2%)    2/56 (4%)    1/56 (2%)  |
|ADJUSTED (b)           |   0.0%         4.3%         0.0%         0.0%      |   2.2%         2.9%         6.5%         2.5%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    1/23 (4%)    0/36 (0%)    0/28 (0%)  |  0/29 (0%)    1/35 (3%)    2/31 (6%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   ---          729 (T)      ---          ---       |   516          733 (T)      733 (T)      617       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.500N     P=0.560        (e)          (e)      |  P=0.597      P=0.745N     P=0.510      P=0.750    |
|INCIDENTAL TUMOR       |  P=0.500N     P=0.560        (e)          (e)      |  P=0.599N     P=0.739      P=0.469      P=0.755N   |
|LOGISTIC REGRESSION    |  P=0.500N     P=0.560        (e)          (e)      |  P=0.589      P=0.754      P=0.500      P=0.743N   |
|COCHRAN-ARMITAGE       |  P=0.565N                                          |  P=0.592                                           |
|FISHER EXACT           |               P=0.500        (e)          (e)      |               P=0.748      P=0.500      P=0.752N   |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE  17
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Uterus                                                                                                                           |
|     Polyp Stromal                                                                                                               |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |                                                    |  2/56 (4%)    5/55 (9%)    6/56 (11%)   2/56 (4%)  |
|ADJUSTED (b)           |                                                    |   6.1%        12.5%        17.6%         4.8%      |
|INTERIM SACRIFICE 1 (c)|                                                    |  0/10 (0%)    1/10 (10%)   0/10 (0%)    1/10 (10%) |
|TERMINAL (d)           |                                                    |  1/29 (3%)    3/35 (9%)    4/31 (13%)   1/33 (3%)  |
|FIRST INCIDENCE (DAYS) |                                                    |   658          457 (I)      650          457 (I)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |                                                    |  P=0.456N     P=0.281      P=0.160      P=0.667N   |
|INCIDENTAL TUMOR       |                                                    |  P=0.554N     P=0.233      P=0.147      P=0.649    |
|LOGISTIC REGRESSION    |                                                    |  P=0.487N     P=0.215      P=0.142      P=0.694N   |
|COCHRAN-ARMITAGE       |                                                    |  P=0.477N                                          |
|FISHER EXACT           |                                                    |               P=0.212      P=0.135      P=0.691N   |
|=================================================================================================================================|
|                                                                                                                                 |
|Uterus                                                                                                                           |
|     Sarcoma Stromal or Polyp Stromal                                                                                            |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |                                                    |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |                                                    |  3/56 (5%)    5/55 (9%)    6/56 (11%)   2/56 (4%)  |
|ADJUSTED (b)           |                                                    |   8.2%        12.5%        17.6%         4.8%      |
|INTERIM SACRIFICE 1 (c)|                                                    |  0/10 (0%)    1/10 (10%)   0/10 (0%)    1/10 (10%) |
|TERMINAL (d)           |                                                    |  1/29 (3%)    3/35 (9%)    4/31 (13%)   1/33 (3%)  |
|FIRST INCIDENCE (DAYS) |                                                    |   516          457 (I)      650          457 (I)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |                                                    |  P=0.343N     P=0.425      P=0.274      P=0.481N   |
|INCIDENTAL TUMOR       |                                                    |  P=0.410N     P=0.348      P=0.240      P=0.521N   |
|LOGISTIC REGRESSION    |                                                    |  P=0.365N     P=0.345      P=0.247      P=0.489N   |
|COCHRAN-ARMITAGE       |                                                    |  P=0.359N                                          |
|FISHER EXACT           |                                                    |               P=0.348      P=0.245      P=0.500N   |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE  18
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|Zymbal's Gland                                                                                                                   |
|     Carcinoma                                                                                                                   |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  0/56 (0%)    3/56 (5%)    1/56 (2%)    1/56 (2%)  |  0/56 (0%)    0/55 (0%)    0/56 (0%)    0/56 (0%)  |
|ADJUSTED (b)           |   0.0%         8.3%         2.6%         1.8%      |   0.0%         0.0%         0.0%         0.0%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    1/23 (4%)    0/36 (0%)    0/28 (0%)  |  0/29 (0%)    0/35 (0%)    0/31 (0%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   ---          436          712          330       |   ---          ---          ---          ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.578N     P=0.148      P=0.649      P=0.500    |    (e)          (e)          (e)          (e)      |
|INCIDENTAL TUMOR       |  P=0.519      P=0.040 *    P=0.343        (e)      |    (e)          (e)          (e)          (e)      |
|LOGISTIC REGRESSION    |  P=0.561      P=0.111      P=0.582        (e)      |    (e)          (e)          (e)          (e)      |
|COCHRAN-ARMITAGE       |  P=0.593                                           |    (e)                                             |
|FISHER EXACT           |               P=0.122      P=0.500      P=0.500    |                 (e)          (e)          (e)      |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Hemangiosarcoma                                                                                                             |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/56 (2%)    1/56 (2%)    0/56 (0%)    2/56 (4%)  |  0/56 (0%)    0/55 (0%)    0/56 (0%)    1/56 (2%)  |
|ADJUSTED (b)           |   5.9%         4.3%         0.0%         6.9%      |   0.0%         0.0%         0.0%         3.0%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  1/17 (6%)    1/23 (4%)    0/36 (0%)    1/28 (4%)  |  0/29 (0%)    0/35 (0%)    0/31 (0%)    1/33 (3%)  |
|FIRST INCIDENCE (DAYS) |   729 (T)      729 (T)      ---          728       |   ---          ---          ---          733 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.497      P=0.694N     P=0.350N     P=0.674    |  P=0.205        (e)          (e)        P=0.526    |
|INCIDENTAL TUMOR       |  P=0.409      P=0.694N     P=0.350N     P=0.563    |  P=0.205        (e)          (e)        P=0.526    |
|LOGISTIC REGRESSION    |  P=0.504      P=0.694N     P=0.350N     P=0.683    |  P=0.205        (e)          (e)        P=0.526    |
|COCHRAN-ARMITAGE       |  P=0.367                                           |  P=0.199                                           |
|FISHER EXACT           |               P=0.752N     P=0.500N     P=0.500    |                 (e)          (e)        P=0.500    |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE  19
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Leukemia: Lymphocytic, Monocytic, Mononuclear, or Undifferentiated                                                          |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 27/56 (48%)   2/56 (4%)    1/56 (2%)    1/56 (2%)  | 15/56 (27%)   1/55 (2%)    0/56 (0%)    1/56 (2%)  |
|ADJUSTED (b)           |  79.2%         8.0%         2.3%         2.6%      |  38.3%         2.5%         0.0%         3.0%      |
|INTERIM SACRIFICE 1 (c)|  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |  1/10 (10%)   0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           | 11/17 (65%)   1/23 (4%)    0/36 (0%)    0/28 (0%)  |  6/29 (21%)   0/35 (0%)    0/31 (0%)    1/33 (3%)  |
|FIRST INCIDENCE (DAYS) |   495          702          552          611       |   457 (I)      659          ---          733 (T)   |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P<0.001N**   P<0.001N**   P<0.001N**   P<0.001N** |  P<0.001N**   P<0.001N**   P<0.001N**   P<0.001N** |
|INCIDENTAL TUMOR       |  P<0.001N**   P<0.001N**   P<0.001N**   P<0.001N** |  P<0.001N**   P<0.001N**   P<0.001N**   P<0.001N** |
|LOGISTIC REGRESSION    |  P<0.001N**   P<0.001N**   P<0.001N**   P<0.001N** |  P<0.001N**   P<0.001N**   P<0.001N**   P<0.001N** |
|COCHRAN-ARMITAGE       |  P<0.001N**                                        |  P<0.001N**                                        |
|FISHER EXACT           |               P<0.001N**   P<0.001N**   P<0.001N** |               P<0.001N**   P<0.001N**   P<0.001N** |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Mesothelioma: Benign, Malignant, NOS                                                                                        |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            |  1/56 (2%)    1/56 (2%)    4/56 (7%)    2/56 (4%)  |  0/56 (0%)    0/55 (0%)    0/56 (0%)    0/56 (0%)  |
|ADJUSTED (b)           |   1.9%         4.3%        10.0%         6.2%      |   0.0%         0.0%         0.0%         0.0%      |
|INTERIM SACRIFICE 1 (c)|  1/10 (10%)   0/10 (0%)    0/10 (0%)    0/10 (0%)  |  0/10 (0%)    0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           |  0/17 (0%)    1/23 (4%)    3/36 (8%)    1/28 (4%)  |  0/29 (0%)    0/35 (0%)    0/31 (0%)    0/33 (0%)  |
|FIRST INCIDENCE (DAYS) |   456 (I)      729 (T)      200          636       |   ---          ---          ---          ---       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.424      P=0.727N     P=0.332      P=0.570    |    (e)          (e)          (e)          (e)      |
|INCIDENTAL TUMOR       |  P=0.470      P=0.727N     P=0.516      P=0.534    |    (e)          (e)          (e)          (e)      |
|LOGISTIC REGRESSION    |  P=0.412      P=0.754      P=0.147      P=0.483    |    (e)          (e)          (e)          (e)      |
|COCHRAN-ARMITAGE       |  P=0.312                                           |    (e)                                             |
|FISHER EXACT           |               P=0.752N     P=0.182      P=0.500    |                 (e)          (e)          (e)      |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE  20
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Benign Tumors                                                                                                               |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 50/56 (89%)  52/56 (93%)  49/56 (88%)  54/56 (96%) | 35/56 (63%)  36/55 (65%)  35/56 (63%)  34/56 (61%) |
|ADJUSTED (b)           |  96.1%       100.0%        96.0%       100.0%      |  78.7%        78.0%        81.4%        77.0%      |
|INTERIM SACRIFICE 1 (c)|  8/10 (80%)   8/10 (80%)   7/10 (70%)  10/10 (100%)|  3/10 (30%)   2/10 (20%)   0/10 (0%)    1/10 (10%) |
|TERMINAL (d)           | 15/17 (88%)  23/23 (100%) 34/36 (94%)  28/28 (100%)| 20/29 (69%)  25/35 (71%)  23/31 (74%)  23/33 (70%) |
|FIRST INCIDENCE (DAYS) |   427          456 (I)      456 (I)      456 (I)   |   457 (I)      378          604          394       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.030N*    P=0.139N     P<0.001N**   P=0.064N   |  P=0.335N     P=0.306N     P=0.436N     P=0.326N   |
|INCIDENTAL TUMOR       |  P=0.124      P=0.382      P=0.596N     P=0.075    |  P=0.533      P=0.426      P=0.529      P=0.574N   |
|LOGISTIC REGRESSION    |  P=0.113      P=0.411      P=0.386N     P=0.172    |  P=0.536N     P=0.502      P=0.485      P=0.542N   |
|COCHRAN-ARMITAGE       |  P=0.156                                           |  P=0.408N                                          |
|FISHER EXACT           |               P=0.371      P=0.500N     P=0.135    |               P=0.450      P=0.577N     P=0.500N   |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant Tumors                                                                                                            |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 32/56 (57%)  15/56 (27%)  14/56 (25%)  15/56 (27%) | 22/56 (39%)   7/55 (13%)   6/56 (11%)   8/56 (14%) |
|ADJUSTED (b)           |  84.5%        46.2%        32.7%        40.1%      |  51.2%        18.0%        16.2%        22.1%      |
|INTERIM SACRIFICE 1 (c)|  2/10 (20%)   0/10 (0%)    0/10 (0%)    0/10 (0%)  |  1/10 (10%)   0/10 (0%)    0/10 (0%)    0/10 (0%)  |
|TERMINAL (d)           | 12/17 (71%)   7/23 (30%)   8/36 (22%)   7/28 (25%) |  9/29 (31%)   4/35 (11%)   2/31 (6%)    6/33 (18%) |
|FIRST INCIDENCE (DAYS) |   415          436          200          330       |   457 (I)      645          504          533       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P<0.001N**   P<0.001N**   P<0.001N**   P<0.001N** |  P=0.005N**   P<0.001N**   P=0.001N**   P=0.003N** |
|INCIDENTAL TUMOR       |  P=0.006N**   P=0.001N**   P=0.002N**   P=0.001N** |  P=0.006N**   P=0.003N**   P<0.001N**   P=0.006N** |
|LOGISTIC REGRESSION    |  P=0.002N**   P<0.001N**   P<0.001N**   P<0.001N** |  P=0.007N**   P=0.005N**   P<0.001N**   P=0.006N** |
|COCHRAN-ARMITAGE       |  P=0.003N**                                        |  P=0.004N**                                        |
|FISHER EXACT           |               P=0.001N**   P<0.001N**   P=0.001N** |               P=0.001N**   P<0.001N**   P=0.003N** |
|=================================================================================================================================|
         DATE: 05/20/95                     EXPERIMENT: 05185 TEST: 03                                                 PAGE  21
                         STATISTICAL ANALYSIS OF PRIMARY TUMORS IN RATS(FISCHER344) -- ISOBUTYL NITRITE (IBN)
                                                 TERMINAL SACRIFICE AT 105 WEEKS
|=================================================================================================================================|
|                       |                                                    |                                                    |
|                       |                       MALES                        |                      FEMALES                       |
|                       |                                                    |                                                    |
|DOSE                   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |   CONTROL      37.5 PPM     75 PPM       150 PPM   |
|                       |                                                    |                                                    |
|=================================================================================================================================|
|                                                                                                                                 |
|All Organs                                                                                                                       |
|     Malignant and Benign Tumors                                                                                                 |
|                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------|
|TUMOR RATES            |    #            #            #            #        |    #            #            #            #        |
|-----------            |                                                    |                                                    |
|OVERALL (a)            | 54/56 (96%)  53/56 (95%)  52/56 (93%)  56/56 (100%)| 44/56 (79%)  36/55 (65%)  37/56 (66%)  36/56 (64%) |
|ADJUSTED (b)           | 100.0%       100.0%        98.1%       100.0%      |  89.6%        78.0%        84.1%        79.8%      |
|INTERIM SACRIFICE 1 (c)|  8/10 (80%)   8/10 (80%)   7/10 (70%)  10/10 (100%)|  4/10 (40%)   2/10 (20%)   0/10 (0%)    1/10 (10%) |
|TERMINAL (d)           | 17/17 (100%) 23/23 (100%) 35/36 (97%)  28/28 (100%)| 24/29 (83%)  25/35 (71%)  24/31 (77%)  24/33 (73%) |
|FIRST INCIDENCE (DAYS) |   415          436          200          330       |   457 (I)      378          504          394       |
|-----------------------|                                                    |                                                    |
|STATISTICAL TESTS (f)  |                                                    |                                                    |
|-----------------------|                                                    |                                                    |
|LIFE TABLE             |  P=0.018N*    P=0.062N     P<0.001N**   P=0.032N*  |  P=0.104N     P=0.023N*    P=0.100N     P=0.057N   |
|INCIDENTAL TUMOR       |  P=0.130      P=0.707      P=0.385N     P=0.234    |  P=0.142N     P=0.096N     P=0.096N     P=0.096N   |
|LOGISTIC REGRESSION    |  P=0.214      P=0.574N     P=0.283N     P=0.224    |  P=0.151N     P=0.061N     P=0.135N     P=0.078N   |
|COCHRAN-ARMITAGE       |  P=0.194                                           |  P=0.099N                                          |
|FISHER EXACT           |               P=0.500N     P=0.339N     P=0.248    |               P=0.092N     P=0.102N     P=0.071N   |
|=================================================================================================================================|
 (a)  Number of tumor-bearing animals / number of animals examined at site.
 (b)  Kaplan-Meier estimated lifetime tumor incidence after adjustment for 
      intercurrent mortality.
 (c)  Observed incidence at interim kill.
          Male interim sacrifices(days):   456
          Female interim sacrifices(days): 457
 (d)  Observed incidence at terminal kill.
 (f)  Beneath the control incidence are the P-values associated with the trend 
      test.  Beneath the dosed group incidence are the P-values corresponding to 
      pairwise comparisons between the controls and that dosed group.  The life
      table analysis regards tumors in animals dying  prior to terminal kill as
      being (directly or indirectly) the cause of death.  The incidental tumor 
      test regards these lesions as non-fatal.  Logistic regression is an alternative
      method for analyzing the incidence of non-fatal tumors.  The Cochran-Armitage
      and Fisher's exact tests compare directly the overall incidence rates.  
      For all tests, a negative trend is indicated by "N".
 (e)  Value of Statistic cannot be computed. 
 (I)  Interim sacrifice
 (T)  Terminal sacrifice
  #   Tumor rates based on number of animals necropsied.
  *   To the right of any statistical result, indicates significance at (P<=0.05).
  **  To the right of any statistical result, indicates significance at (P<=0.01).