https://ntp.niehs.nih.gov/go/12888

TDMS Study 90004-06 Pathology Tables

NTP Experiment-Test: 90004-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                PROPYLENE GLYCOL MONO-T-BUTYL ETHER                            Date: 01/02/02
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:38
                                                           FINAL/MICE
       Facility:  Battelle Northwest
       Chemical CAS #:  57018-52-7
       Lock Date:  12/11/00
       Cage Range:  All
       Reasons For Removal:    All
       Removal Date Range:     All
       Treatment Groups:       Include All
a  Number of animals examined microscopically at site and number of animals with lesion
                                                              Page   1
NTP Experiment-Test: 90004-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                PROPYLENE GLYCOL MONO-T-BUTYL ETHER                            Date: 01/02/02    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:38    
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      75 PPM       300 PPM      1200 PPM                                  
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 8           10            6            4                                     
    Natural Death                                      3            3            2            6                                     
    Accidently Killed                                               1                         1                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                39           36           41           38                                     
    Natural Death                                                                1            1                                     
  Animals Examined Microscopically                    50           50           50           49                                     
____________________________________________________________________________________________________________________________________
 ALIMENTARY SYSTEM                                                                                                                  
   Gallbladder                                        (40)         (39)         (43)         (33)                                   
      Cyst                                             1 (3%)                                                                       
   Intestine Large, Colon                             (48)         (49)         (50)         (48)                                   
      Infiltration Cellular, Mixed Cell                                                       1 (2%)                                
   Intestine Large, Rectum                            (48)         (49)         (50)         (48)                                   
      Necrosis                                                                                1 (2%)                                
   Intestine Large, Cecum                             (49)         (48)         (49)         (46)                                   
      Necrosis                                                                   2 (4%)                                             
   Intestine Small, Duodenum                          (49)         (47)         (50)         (46)                                   
      Infiltration Cellular, Mixed Cell                                                       1 (2%)                                
      Epithelium, Hyperplasia                                                    1 (2%)                                             
   Intestine Small, Jejunum                           (49)         (48)         (48)         (47)                                   
      Infiltration Cellular, Mixed Cell                                          1 (2%)                                             
      Inflammation, Suppurative                                                               1 (2%)                                
      Necrosis                                                                                1 (2%)                                
   Intestine Small, Ileum                             (49)         (48)         (48)         (45)                                   
      Hyperplasia                                      1 (2%)                                                                       
      Infiltration Cellular, Mixed Cell                2 (4%)       1 (2%)       3 (6%)       1 (2%)                                
      Necrosis                                                                                2 (4%)                                
      Epithelium, Hyperplasia                          1 (2%)                                                                       
   Liver                                              (49)         (50)         (50)         (49)                                   
      Angiectasis                                                                1 (2%)                                             
      Basophilic Focus                                 3 (6%)       4 (8%)       4 (8%)       2 (4%)                                
      Clear Cell Focus                                 4 (8%)       4 (8%)       6 (12%)      5 (10%)                               
      Eosinophilic Focus                              11 (22%)     10 (20%)      9 (18%)     27 (55%)                               
      Fatty Change                                     2 (4%)       1 (2%)       1 (2%)       1 (2%)                                
      Fatty Change, Focal                                           1 (2%)                                                          
      Hematopoietic Cell Proliferation                                           1 (2%)                                             
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    2                                                              
NTP Experiment-Test: 90004-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                PROPYLENE GLYCOL MONO-T-BUTYL ETHER                            Date: 01/02/02    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:38    
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      75 PPM       300 PPM      1200 PPM                                  
____________________________________________________________________________________________________________________________________
ALIMENTARY SYSTEM - CONT                                                                                                            
      Infarct                                                                    1 (2%)                                             
      Inflammation, Granulomatous                     23 (47%)      9 (18%)     17 (34%)     12 (24%)                               
      Tension Lipidosis                                4 (8%)       3 (6%)       6 (12%)      4 (8%)                                
      Thrombosis                                                                 1 (2%)                                             
      Bile Duct, Cyst                                  1 (2%)                                                                       
      Bile Duct, Hyperplasia                                        1 (2%)       1 (2%)                                             
      Centrilobular, Necrosis                                       3 (6%)                                                          
      Hepatocyte, Mitotic Alteration                                1 (2%)                                                          
   Mesentery                                          (17)         (21)         (13)         (2)                                    
      Infiltration Cellular, Mast Cell                 1 (6%)                                                                       
      Fat, Congestion                                  1 (6%)                                                                       
      Fat, Necrosis                                   14 (82%)     19 (90%)     12 (92%)      2 (100%)                              
   Oral Mucosa                                        (1)                                                                           
      Inflammation                                     1 (100%)                                                                     
   Pancreas                                           (49)         (50)         (50)         (48)                                   
      Atrophy                                          1 (2%)                    2 (4%)                                             
      Basophilic Focus                                 1 (2%)       1 (2%)       1 (2%)                                             
      Duct, Cyst                                                                 1 (2%)                                             
   Salivary Glands                                    (50)         (50)         (50)         (49)                                   
      Atrophy                                                                                 1 (2%)                                
   Stomach, Forestomach                               (49)         (50)         (50)         (48)                                   
      Hyperplasia, Squamous                            3 (6%)       5 (10%)      1 (2%)       6 (13%)                               
      Infiltration Cellular, Mast Cell                                           1 (2%)                                             
      Infiltration Cellular, Mixed Cell                1 (2%)                                                                       
      Inflammation                                     2 (4%)       5 (10%)      2 (4%)       6 (13%)                               
      Ulcer                                            2 (4%)                    1 (2%)       4 (8%)                                
   Stomach, Glandular                                 (49)         (48)         (50)         (48)                                   
      Mineralization                                   2 (4%)       1 (2%)       1 (2%)       1 (2%)                                
   Tooth                                              (50)         (50)         (50)         (49)                                   
      Inflammation, Chronic Active                     1 (2%)       2 (4%)       1 (2%)       7 (14%)                               
      Malformation                                     1 (2%)       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
 CARDIOVASCULAR SYSTEM                                                                                                              
   Blood Vessel                                                                 (2)                                                 
      Inflammation, Chronic                                                      1 (50%)                                            
   Heart                                              (50)         (50)         (50)         (49)                                   
      Cardiomyopathy                                   5 (10%)      4 (8%)       8 (16%)      3 (6%)                                
      Inflammation, Chronic                                         1 (2%)                                                          
      Mineralization                                   1 (2%)       1 (2%)                                                          
      Thrombosis                                                                              1 (2%)                                
      Artery, Inflammation, Chronic Active             1 (2%)                                                                       
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    3                                                              
NTP Experiment-Test: 90004-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                PROPYLENE GLYCOL MONO-T-BUTYL ETHER                            Date: 01/02/02    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:38    
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      75 PPM       300 PPM      1200 PPM                                  
____________________________________________________________________________________________________________________________________
CARDIOVASCULAR SYSTEM - CONT                                                                                                        
      Endocardium, Hyperplasia                                      1 (2%)                                                          
      Valve, Inflammation, Suppurative                              1 (2%)                                                          
____________________________________________________________________________________________________________________________________
 ENDOCRINE SYSTEM                                                                                                                   
   Adrenal Cortex                                     (49)         (50)         (50)         (48)                                   
      Hyperplasia                                      8 (16%)      3 (6%)       3 (6%)       4 (8%)                                
      Hypertrophy                                      7 (14%)      7 (14%)      1 (2%)       2 (4%)                                
      Necrosis                                         1 (2%)       1 (2%)                                                          
      Vacuolization Cytoplasmic                                     3 (6%)       3 (6%)                                             
   Adrenal Medulla                                    (47)         (49)         (50)         (48)                                   
      Hyperplasia                                      2 (4%)       4 (8%)       1 (2%)       3 (6%)                                
      Hypertrophy                                                                             1 (2%)                                
      Necrosis                                         1 (2%)                                                                       
   Islets, Pancreatic                                 (49)         (50)         (50)         (48)                                   
      Hyperplasia                                      1 (2%)                                 1 (2%)                                
   Pituitary Gland                                    (48)         (49)         (47)         (46)                                   
      Pars Distalis, Angiectasis                       1 (2%)                    1 (2%)       1 (2%)                                
      Pars Distalis, Hyperplasia                      16 (33%)     11 (22%)     16 (34%)     11 (24%)                               
   Thyroid Gland                                      (49)         (50)         (50)         (48)                                   
      Follicular Cell, Hyperplasia                     2 (4%)       1 (2%)       3 (6%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
 GENERAL BODY SYSTEM                                                                                                                
   Peritoneum                                                      (1)          (2)                                                 
      Inflammation, Chronic, Suppurative                            1 (100%)                                                        
____________________________________________________________________________________________________________________________________
 GENITAL SYSTEM                                                                                                                     
   Clitoral Gland                                     (42)         (43)         (48)         (45)                                   
      Inflammation, Chronic                                         1 (2%)                                                          
   Ovary                                              (50)         (49)         (49)         (48)                                   
      Angiectasis                                      1 (2%)       1 (2%)                                                          
      Atrophy                                                                                 1 (2%)                                
      Cyst                                            12 (24%)     12 (24%)     12 (24%)     11 (23%)                               
      Inflammation, Chronic Active                                  1 (2%)                                                          
      Thrombosis                                                                 1 (2%)                                             
   Uterus                                             (50)         (50)         (50)         (48)                                   
      Angiectasis                                      3 (6%)       1 (2%)       4 (8%)       2 (4%)                                
      Inflammation, Suppurative                                     1 (2%)       2 (4%)       2 (4%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    4                                                              
NTP Experiment-Test: 90004-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                PROPYLENE GLYCOL MONO-T-BUTYL ETHER                            Date: 01/02/02    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:38    
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      75 PPM       300 PPM      1200 PPM                                  
____________________________________________________________________________________________________________________________________
GENITAL SYSTEM - CONT                                                                                                               
      Thrombosis                                                    2 (4%)                                                          
      Endometrium, Fibrosis                            1 (2%)                                                                       
      Endometrium, Hyperplasia, Cystic                46 (92%)     48 (96%)     48 (96%)     45 (94%)                               
____________________________________________________________________________________________________________________________________
 HEMATOPOIETIC SYSTEM                                                                                                               
   Bone Marrow                                        (49)         (50)         (50)         (48)                                   
      Thrombosis                                                                              1 (2%)                                
   Lymph Node                                         (4)          (8)          (6)          (2)                                    
      Angiectasis                                                   2 (25%)                                                         
      Ectasia                                                                    1 (17%)                                            
      Lumbar, Angiectasis                              1 (25%)                                                                      
      Renal, Angiectasis                               1 (25%)                                                                      
      Renal, Ectasia                                   1 (25%)                                                                      
   Lymph Node, Mandibular                             (44)         (45)         (45)         (34)                                   
      Hyperplasia, Lymphoid                                                                   1 (3%)                                
      Infiltration Cellular, Plasma Cell                                                      1 (3%)                                
   Lymph Node, Mesenteric                             (48)         (48)         (48)         (48)                                   
      Angiectasis                                      1 (2%)       2 (4%)       2 (4%)       1 (2%)                                
      Infiltration Cellular, Plasma Cell                            1 (2%)                                                          
      Inflammation, Granulomatous                                                1 (2%)                                             
      Inflammation, Suppurative                                                               1 (2%)                                
   Lymph Node, Mediastinal                            (40)         (41)         (41)         (31)                                   
      Hemorrhage                                       1 (3%)                                                                       
   Spleen                                             (49)         (50)         (50)         (48)                                   
      Fibrosis                                                      1 (2%)                                                          
      Hematopoietic Cell Proliferation                 4 (8%)       4 (8%)       2 (4%)       3 (6%)                                
____________________________________________________________________________________________________________________________________
 INTEGUMENTARY SYSTEM                                                                                                               
   Skin                                               (50)         (50)         (50)         (49)                                   
      Hyperplasia, Squamous                            1 (2%)                                                                       
      Infiltration Cellular, Mixed Cell                1 (2%)       3 (6%)       2 (4%)                                             
      Inflammation, Acute                                                                     1 (2%)                                
      Inflammation, Chronic Active                                                            1 (2%)                                
      Subcutaneous Tissue, Inflammation, Acute                      1 (2%)                                                          
____________________________________________________________________________________________________________________________________
 MUSCULOSKELETAL SYSTEM                                                                                                             
   Bone                                               (50)         (50)         (50)         (49)                                   
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    5                                                              
NTP Experiment-Test: 90004-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                PROPYLENE GLYCOL MONO-T-BUTYL ETHER                            Date: 01/02/02    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:38    
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      75 PPM       300 PPM      1200 PPM                                  
____________________________________________________________________________________________________________________________________
MUSCULOSKELETAL SYSTEM - CONT                                                                                                       
      Synovial Tissue, Hyperplasia                                               1 (2%)                                             
   Skeletal Muscle                                    (1)          (2)                                                              
      Hemorrhage                                       1 (100%)                                                                     
      Inflammation, Acute                                           1 (50%)                                                         
____________________________________________________________________________________________________________________________________
 NERVOUS SYSTEM                                                                                                                     
   Brain                                              (50)         (50)         (50)         (49)                                   
      Meninges, Infiltration Cellular, Mononuclear                                                                                  
          Cell                                         1 (2%)                                                                       
   Spinal Cord                                        (2)                                                                           
      Hemorrhage                                       1 (50%)                                                                      
____________________________________________________________________________________________________________________________________
 RESPIRATORY SYSTEM                                                                                                                 
   Larynx                                             (50)         (50)         (50)         (48)                                   
      Metaplasia, Squamous                             1 (2%)                                                                       
   Lung                                               (50)         (50)         (50)         (49)                                   
      Foreign Body                                                               1 (2%)                                             
      Inflammation, Granulomatous                                                             2 (4%)                                
      Mineralization                                                             1 (2%)                                             
      Thrombosis                                       1 (2%)                                 2 (4%)                                
      Alveolar Epithelium, Hyperplasia                 3 (6%)       2 (4%)       4 (8%)       3 (6%)                                
      Alveolus, Infiltration Cellular, Histiocyte      2 (4%)       1 (2%)                    3 (6%)                                
      Artery, Inflammation, Acute                                                             2 (4%)                                
   Nose                                               (50)         (50)         (49)         (49)                                   
      Inflammation, Acute                                           1 (2%)                                                          
      Inflammation, Suppurative                        3 (6%)                    1 (2%)       1 (2%)                                
      Respiratory Epithelium, Metaplasia, Squamous     2 (4%)                                                                       
      Respiratory Epithelium, Necrosis                 2 (4%)                                 1 (2%)                                
   Pleura                                                          (1)          (1)                                                 
      Hyperplasia                                                   1 (100%)                                                        
____________________________________________________________________________________________________________________________________
 SPECIAL SENSES SYSTEM                                                                                                              
   Eye                                                (50)         (50)         (50)         (48)                                   
      Cataract                                                                                2 (4%)                                
      Anterior Chamber, Inflammation, Acute            1 (2%)                                 1 (2%)                                
      Cornea, Erosion                                                                         3 (6%)                                
      Cornea, Hyperplasia, Squamous                    1 (2%)       2 (4%)                    2 (4%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    6                                                              
NTP Experiment-Test: 90004-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                PROPYLENE GLYCOL MONO-T-BUTYL ETHER                            Date: 01/02/02    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:38    
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      75 PPM       300 PPM      1200 PPM                                  
____________________________________________________________________________________________________________________________________
SPECIAL SENSES SYSTEM - CONT                                                                                                        
      Cornea, Inflammation, Acute                                                             1 (2%)                                
      Cornea, Inflammation, Chronic Active             1 (2%)       2 (4%)                    4 (8%)                                
      Cornea, Mineralization                           1 (2%)       2 (4%)                   20 (42%)                               
      Cornea, Ulcer                                                 1 (2%)                    1 (2%)                                
      Retrobulbar, Inflammation, Granulomatous                                                1 (2%)                                
   Harderian Gland                                    (50)         (50)         (50)         (49)                                   
      Hyperplasia                                      3 (6%)       3 (6%)       4 (8%)       4 (8%)                                
____________________________________________________________________________________________________________________________________
 URINARY SYSTEM                                                                                                                     
   Kidney                                             (49)         (50)         (50)         (48)                                   
      Infarct                                          1 (2%)                    2 (4%)       3 (6%)                                
      Metaplasia, Osseous                              2 (4%)       1 (2%)       1 (2%)       1 (2%)                                
      Nephropathy                                     34 (69%)     34 (68%)     32 (64%)     34 (71%)                               
      Thrombosis                                                                 1 (2%)                                             
      Pelvis, Dilatation                                                         1 (2%)                                             
      Renal Tubule, Degeneration, Hyaline              1 (2%)                                 1 (2%)                                
      Renal Tubule, Necrosis                                                     1 (2%)                                             
   Urinary Bladder                                    (50)         (49)         (50)         (47)                                   
      Inflammation, Acute                                                                     1 (2%)                                
      Transitional Epithelium, Hyperplasia             1 (2%)                                                                       
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    7                                                              
NTP Experiment-Test: 90004-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                PROPYLENE GLYCOL MONO-T-BUTYL ETHER                            Date: 01/02/02    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:38    
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      75 PPM       300 PPM      1200 PPM                                  
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Natural Death                                     11            4            4            5                                     
    Moribund Sacrifice                                 4            6            6            8                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                35           40           40           37                                     
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
 ALIMENTARY SYSTEM                                                                                                                  
   Gallbladder                                        (38)         (41)         (39)         (40)                                   
      Degeneration, Hyaline                                         1 (2%)       2 (5%)                                             
   Intestine Large, Colon                             (46)         (48)         (48)         (47)                                   
      Serosa, Inflammation, Granulomatous                           1 (2%)                                                          
   Intestine Large, Rectum                            (46)         (48)         (48)         (46)                                   
      Infiltration Cellular, Mixed Cell                1 (2%)                                                                       
   Intestine Large, Cecum                             (43)         (47)         (48)         (48)                                   
      Necrosis                                         1 (2%)       1 (2%)                                                          
   Intestine Small, Jejunum                           (42)         (47)         (47)         (45)                                   
      Infiltration Cellular, Mixed Cell                2 (5%)                    2 (4%)                                             
      Inflammation, Granulomatous                      1 (2%)       1 (2%)                                                          
      Necrosis                                                                   1 (2%)                                             
      Epithelium, Hyperplasia                          1 (2%)                                                                       
   Intestine Small, Ileum                             (43)         (47)         (46)         (46)                                   
      Infiltration Cellular, Mixed Cell                4 (9%)       2 (4%)       2 (4%)       1 (2%)                                
      Inflammation, Acute                                                        1 (2%)                                             
      Inflammation, Chronic Active                                  1 (2%)       1 (2%)                                             
      Necrosis                                                                   1 (2%)                                             
      Epithelium, Hyperplasia                          1 (2%)       1 (2%)                                                          
   Liver                                              (50)         (49)         (50)         (50)                                   
      Basophilic Focus                                 6 (12%)     11 (22%)     16 (32%)      4 (8%)                                
      Clear Cell Focus                                20 (40%)     18 (37%)     16 (32%)     17 (34%)                               
      Eosinophilic Focus                               9 (18%)     14 (29%)     11 (22%)     29 (58%)                               
      Fatty Change                                                  1 (2%)                    2 (4%)                                
      Hematopoietic Cell Proliferation                 1 (2%)       1 (2%)       1 (2%)                                             
      Infarct                                          2 (4%)       1 (2%)       1 (2%)       3 (6%)                                
      Inflammation, Granulomatous                      9 (18%)     12 (24%)     11 (22%)      3 (6%)                                
      Mixed Cell Focus                                                                        4 (8%)                                
      Tension Lipidosis                                1 (2%)       2 (4%)       4 (8%)       2 (4%)                                
      Centrilobular, Necrosis                          1 (2%)       1 (2%)       1 (2%)                                             
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    8                                                              
NTP Experiment-Test: 90004-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                PROPYLENE GLYCOL MONO-T-BUTYL ETHER                            Date: 01/02/02    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:38    
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      75 PPM       300 PPM      1200 PPM                                  
____________________________________________________________________________________________________________________________________
ALIMENTARY SYSTEM - CONT                                                                                                            
      Hepatocyte, Multinucleated                      27 (54%)     23 (47%)     24 (48%)     46 (92%)                               
   Mesentery                                          (14)         (16)         (13)         (11)                                   
      Inflammation, Granulomatous                      2 (14%)      1 (6%)       4 (31%)      1 (9%)                                
      Artery, Inflammation                                                       1 (8%)       2 (18%)                               
      Fat, Necrosis                                   10 (71%)     14 (88%)      7 (54%)      7 (64%)                               
   Pancreas                                           (48)         (49)         (50)         (50)                                   
      Atrophy                                                       1 (2%)                                                          
      Basophilic Focus                                                                        1 (2%)                                
   Stomach, Forestomach                               (48)         (49)         (50)         (50)                                   
      Hyperkeratosis                                                             1 (2%)                                             
      Hyperplasia, Squamous                                                                   1 (2%)                                
      Inflammation                                     2 (4%)       3 (6%)       9 (18%)      9 (18%)                               
      Ulcer                                                                                   1 (2%)                                
      Artery, Inflammation, Chronic Active                                       1 (2%)                                             
      Epithelium, Hyperplasia, Squamous                2 (4%)       5 (10%)      9 (18%)      7 (14%)                               
      Epithelium, Ulcer                                1 (2%)       1 (2%)       3 (6%)       3 (6%)                                
   Stomach, Glandular                                 (46)         (48)         (50)         (48)                                   
      Hyperplasia                                      1 (2%)                                                                       
      Metaplasia, Squamous                             1 (2%)                                                                       
      Mineralization                                   1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Necrosis                                                      2 (4%)       1 (2%)                                             
   Tooth                                              (50)         (50)         (50)         (50)                                   
      Inflammation, Chronic Active                     3 (6%)       5 (10%)      4 (8%)      15 (30%)                               
      Malformation                                    24 (48%)     15 (30%)     15 (30%)     16 (32%)                               
____________________________________________________________________________________________________________________________________
 CARDIOVASCULAR SYSTEM                                                                                                              
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                   9 (18%)      8 (16%)     11 (22%)      7 (14%)                               
      Mineralization                                   1 (2%)       1 (2%)                                                          
      Necrosis                                         2 (4%)                                                                       
      Thrombosis                                                                 1 (2%)       1 (2%)                                
      Artery, Inflammation, Chronic Active                                       3 (6%)                                             
____________________________________________________________________________________________________________________________________
 ENDOCRINE SYSTEM                                                                                                                   
   Adrenal Cortex                                     (48)         (49)         (50)         (50)                                   
      Hyperplasia                                     11 (23%)      9 (18%)     14 (28%)      7 (14%)                               
      Hypertrophy                                     34 (71%)     32 (65%)     29 (58%)     18 (36%)                               
   Adrenal Medulla                                    (47)         (49)         (49)         (49)                                   
      Hyperplasia                                                   1 (2%)       1 (2%)       2 (4%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    9                                                              
NTP Experiment-Test: 90004-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                PROPYLENE GLYCOL MONO-T-BUTYL ETHER                            Date: 01/02/02    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:38    
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      75 PPM       300 PPM      1200 PPM                                  
____________________________________________________________________________________________________________________________________
ENDOCRINE SYSTEM - CONT                                                                                                             
      Infiltration Cellular, Polymorphonuclear                                   1 (2%)                                             
   Islets, Pancreatic                                 (48)         (49)         (50)         (50)                                   
      Hyperplasia                                                   1 (2%)                                                          
   Pituitary Gland                                    (43)         (48)         (50)         (48)                                   
      Cyst                                                          1 (2%)                                                          
      Pars Distalis, Hyperplasia                                    1 (2%)       4 (8%)       1 (2%)                                
   Thyroid Gland                                      (48)         (48)         (49)         (49)                                   
      Follicular Cell, Hyperplasia                                               1 (2%)                                             
____________________________________________________________________________________________________________________________________
 GENERAL BODY SYSTEM                                                                                                                
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
 GENITAL SYSTEM                                                                                                                     
   Epididymis                                         (50)         (50)         (50)         (50)                                   
      Granuloma Sperm                                  1 (2%)       1 (2%)                                                          
      Inflammation, Chronic                                         1 (2%)                                                          
   Preputial Gland                                    (50)         (50)         (50)         (50)                                   
      Ectasia                                          2 (4%)       1 (2%)       1 (2%)                                             
      Hyperplasia, Squamous                            1 (2%)                                 2 (4%)                                
      Inflammation, Chronic                                         2 (4%)       2 (4%)                                             
      Inflammation, Suppurative                                     3 (6%)       2 (4%)       2 (4%)                                
   Prostate                                           (49)         (49)         (47)         (50)                                   
      Inflammation, Suppurative                                                  1 (2%)                                             
      Artery, Inflammation, Chronic Active                          1 (2%)       1 (2%)                                             
   Seminal Vesicle                                    (47)         (49)         (49)         (49)                                   
      Inflammation, Chronic                                         2 (4%)       1 (2%)                                             
   Testes                                             (50)         (50)         (50)         (50)                                   
      Amyloid Deposition                                            1 (2%)                                                          
      Atrophy                                                       1 (2%)       1 (2%)                                             
      Mineralization                                   1 (2%)                                                                       
      Germinal Epithelium, Degeneration                1 (2%)                                 1 (2%)                                
____________________________________________________________________________________________________________________________________
 HEMATOPOIETIC SYSTEM                                                                                                               
   Bone Marrow                                        (49)         (49)         (50)         (50)                                   
      Thrombosis                                                                              1 (2%)                                
   Lymph Node, Bronchial                              (32)         (36)         (36)         (35)                                   
      Infiltration Cellular, Plasma Cell               1 (3%)                                                                       
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   10                                                              
NTP Experiment-Test: 90004-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                PROPYLENE GLYCOL MONO-T-BUTYL ETHER                            Date: 01/02/02    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:38    
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      75 PPM       300 PPM      1200 PPM                                  
____________________________________________________________________________________________________________________________________
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
   Lymph Node, Mandibular                             (28)         (38)         (30)         (25)                                   
      Infiltration Cellular, Plasma Cell                                                      1 (4%)                                
   Lymph Node, Mesenteric                             (48)         (49)         (49)         (50)                                   
      Angiectasis                                                                1 (2%)                                             
      Infiltration Cellular, Plasma Cell               2 (4%)       1 (2%)       4 (8%)                                             
      Infiltration Cellular, Mixed Cell                1 (2%)                                                                       
      Pigmentation                                                  1 (2%)                                                          
   Lymph Node, Mediastinal                            (39)         (39)         (43)         (36)                                   
      Inflammation, Granulomatous                                   1 (3%)                                                          
   Spleen                                             (48)         (48)         (50)         (50)                                   
      Angiectasis                                                                             1 (2%)                                
      Hematopoietic Cell Proliferation                 4 (8%)       2 (4%)       2 (4%)       2 (4%)                                
      Hyperplasia, Lymphoid                                                                   1 (2%)                                
      Infiltration Cellular, Histiocyte                1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
 INTEGUMENTARY SYSTEM                                                                                                               
   Skin                                               (49)         (50)         (50)         (50)                                   
      Infiltration Cellular, Mixed Cell                             1 (2%)                                                          
      Inflammation, Chronic Active                     4 (8%)       1 (2%)       6 (12%)      5 (10%)                               
      Epidermis, Hyperplasia                                                                  1 (2%)                                
      Subcutaneous Tissue, Edema                       1 (2%)                                                                       
      Subcutaneous Tissue, Hemorrhage                  1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
 MUSCULOSKELETAL SYSTEM                                                                                                             
   Bone                                               (50)         (50)         (50)         (50)                                   
      Fibrous Osteodystrophy                           1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
 NERVOUS SYSTEM                                                                                                                     
   Brain                                              (50)         (50)         (50)         (50)                                   
      Necrosis                                         1 (2%)                                                                       
      Artery, Inflammation, Chronic Active                                       1 (2%)                                             
____________________________________________________________________________________________________________________________________
 RESPIRATORY SYSTEM                                                                                                                 
   Larynx                                             (49)         (50)         (50)         (50)                                   
      Artery, Inflammation, Chronic Active                                       1 (2%)                                             
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   11                                                              
NTP Experiment-Test: 90004-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                PROPYLENE GLYCOL MONO-T-BUTYL ETHER                            Date: 01/02/02    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:38    
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      75 PPM       300 PPM      1200 PPM                                  
____________________________________________________________________________________________________________________________________
RESPIRATORY SYSTEM - CONT                                                                                                           
   Lung                                               (50)         (50)         (50)         (50)                                   
      Hemorrhage                                                    1 (2%)                    1 (2%)                                
      Inflammation, Granulomatous                                   1 (2%)                    1 (2%)                                
      Inflammation, Suppurative                                                  1 (2%)                                             
      Mineralization                                                1 (2%)                                                          
      Thrombosis                                                    3 (6%)                                                          
      Alveolar Epithelium, Hyperplasia                 6 (12%)      4 (8%)       4 (8%)                                             
      Alveolus, Infiltration Cellular, Histiocyte      1 (2%)                                 2 (4%)                                
   Nose                                               (50)         (49)         (50)         (50)                                   
      Amyloid Deposition                                            1 (2%)                                                          
      Inflammation, Suppurative                        5 (10%)                   4 (8%)       6 (12%)                               
      Olfactory Epithelium, Atrophy                                              1 (2%)                                             
      Respiratory Epithelium, Metaplasia, Squamous                                            1 (2%)                                
      Respiratory Epithelium, Necrosis                                           1 (2%)       1 (2%)                                
   Pleura                                             (1)                       (1)                                                 
      Necrosis, Fatty                                                            1 (100%)                                           
   Trachea                                            (48)         (48)         (50)         (50)                                   
      Degeneration, Hyaline                                                      1 (2%)                                             
      Inflammation, Suppurative                                                  1 (2%)                                             
____________________________________________________________________________________________________________________________________
 SPECIAL SENSES SYSTEM                                                                                                              
   Eye                                                (48)         (49)         (50)         (50)                                   
      Cornea, Erosion                                                                         1 (2%)                                
      Cornea, Hyperplasia, Squamous                    1 (2%)                                 1 (2%)                                
      Cornea, Inflammation, Chronic Active             1 (2%)                    1 (2%)       1 (2%)                                
      Cornea, Mineralization                                                                  3 (6%)                                
   Harderian Gland                                    (50)         (50)         (50)         (50)                                   
      Hyperplasia                                     10 (20%)      3 (6%)       5 (10%)      1 (2%)                                
   Zymbal's Gland                                     (35)         (35)         (36)         (32)                                   
      Hyperplasia                                      1 (3%)                                                                       
____________________________________________________________________________________________________________________________________
 URINARY SYSTEM                                                                                                                     
   Kidney                                             (50)         (49)         (50)         (50)                                   
      Amyloid Deposition                                            1 (2%)                                                          
      Cyst                                             1 (2%)       1 (2%)       2 (4%)                                             
      Infarct                                          3 (6%)       3 (6%)       3 (6%)       7 (14%)                               
      Inflammation, Chronic, Suppurative                            1 (2%)                    1 (2%)                                
      Metaplasia, Osseous                              3 (6%)       6 (12%)      2 (4%)                                             
      Mineralization                                                1 (2%)                                                          
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   12                                                              
NTP Experiment-Test: 90004-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                PROPYLENE GLYCOL MONO-T-BUTYL ETHER                            Date: 01/02/02    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 08:46:38    
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      75 PPM       300 PPM      1200 PPM                                  
____________________________________________________________________________________________________________________________________
URINARY SYSTEM - CONT                                                                                                               
      Nephropathy                                     41 (82%)     40 (82%)     44 (88%)     36 (72%)                               
      Artery, Inflammation, Chronic Active                                       2 (4%)       1 (2%)                                
      Papilla, Inflammation, Suppurative                                         1 (2%)                                             
      Pelvis, Dilatation                                                         1 (2%)       2 (4%)                                
      Renal Tubule, Hyperplasia                        2 (4%)                    1 (2%)                                             
      Renal Tubule, Necrosis                           1 (2%)                                                                       
      Transitional Epithelium, Hyperplasia                                                    2 (4%)                                
   Urinary Bladder                                    (48)         (48)         (49)         (50)                                   
      Inflammation, Chronic Active                                               1 (2%)                                             
      Artery, Inflammation, Chronic Active                          1 (2%)       1 (2%)                                             
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   13                                                              
                             ------------------------------------------------------------                                           
                             ----------              END OF REPORT             ----------                                           
                             ------------------------------------------------------------