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Target Organs and Levels of Evidence for TR-421

Toxicology and Carcinogenesis Studies of Talc (CASRN 14807-96-6) in F344/N Rats and B6C3F1 Mice (Inhalation Studies)

Chemical (Study Title) CASRN	Peer Review Date	Route/Exposure Levels	Study Laboratory
Talc 14807-96-6	06/23/1992	Inhalation R & M: 0, 6, AND 18 MG OF TALC/M3 OF ATMOSPHERE	Lovelace Biomedical & Environmental Research Institute

Levels of Evidence

Male Rats: Some Evidence

Type	Organ/Tissue (Lesion)
Neoplastic Lesions	Adrenal Gland Medulla: PHEOCHROMOCYTOMA 25/49 30/48 36/47 OR MALIGNANT PHEOCHROMOCYTOMA 3/49 3/48 7/47 COMBINED 26/49 32/48 37/47
Non-Neoplastic Lesions	LUNG: GRANULOMATOUS INFLAMMATION; INTERSTITIAL FIBROSIS; ALVEOLAR EPITHELIAL HYPERPLASIA; PERIBRONCHIAL HYPERPLASIA; ALVEOLAR SQUAMOUS METAPLASIA LYMPH NODE: (BRONCHIAL) HISTIOCYTIC HYPERPLASIA; (MEDIASTINAL) HISTIOCYTIC HYPERPLASIA NASAL CAVITY: RESPIRATORY EPITHELIAL HYPERPLASIA; CYTOPLASMIC ALTERATION

Female Rats: Clear Evidence

Type	Organ/Tissue (Lesion)
Neoplastic Lesions	Lung: ALVEOLAR/BRONCHIOLAR ADENOMA 1/50 0/48 9/50 OR ALVEOLAR/BRONCHIOLAR CARCINOMA 0/50 0/48 5/50 COMBINED 1/50 0/48 13/50 Adrenal Gland Medulla: PHEOCHROMOCYTOMA 13/48 14/47 18/49 OR MALIGNANT PHEOCHROMOCYTOMA 0/48 1/47 10/49 COMBINED 13/48 14/47 23/49
Non-Neoplastic Lesions	LUNG: GRANULOMATOUS INFLAMMATION; INTERSTITIAL FIBROSIS; ALVEOLAR EPITHELIAL HYPERPLASIA; PERIBRONCHIAL HYPERPLASIA; CYST; ALVEOLAR SQUAMOUS METAPLASIA LYMPH NODE: (BRONCHIAL) HISTIOCYTIC HYPERPLASIA; (MEDIASTINAL) HISTIOCYTIC HYPERPLASIA NASAL CAVITY: CYTOPLASMIC ALTERATION

Male Mice: No Evidence

Type	Organ/Tissue (Lesion)
Non-Neoplastic Lesions	LUNG: CHRONIC INFLAMMATION; MACROPHAGE HYPERPLASIA LYMPH NODE: (BRONCHIAL) HISTIOCYTIC HYPERPLASIA NASAL CAVITY: CYTOPLASMIC ALTERATION

Female Mice: No Evidence

Type	Organ/Tissue (Lesion)
Non-Neoplastic Lesions	LUNG: CHRONIC INFLAMMATION; MACROPHAGE HYPERPLASIA LYMPH NODE: (BRONCHIAL) HISTIOCYTIC HYPERPLASIA NASAL CAVITY: CYTOPLASMIC ALTERATION