[Federal Register Volume 59, Number 137 (Tuesday, July 19, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-17454]


[[Page Unknown]]

[Federal Register: July 19, 1994]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES
 

National Toxicology Program; Availability of Technical Report on 
Toxicology and Carcinogenesis Studies of 1,2,3-Trichloropropane

    The HHS' National Toxicology Program announces the availability of 
the NTP Technical Report on the toxicology and carcinogenesis studies 
of 1,2,3-Trichloropropane, a colorless liquid used as a paint and 
varnish remover, solvent, and degreasing agent, and as a crosslinking 
agent in the synthesis of polysulfides and hexafluoropropylene. 1,2,3-
Trichloropropane may be found as an impurity in certain nematocides and 
soil fumigants and as a contaminant of drinking and ground water.
    Toxicology and carcinogenesis studies were performed by 
administering 1,2,3-trichloropropane in corn oil by gavage to groups of 
60 F344/N rats of each sex at doses of 0, 3, 10, or 30 mg/kg body 
weight and to 60 B6C3F1 mice of each sex at doses of 0, 6, 20, or 
60 mg/kg body weight 5 days per week for up to 104 weeks.
    Under the conditions of these 2-year gavage studies, there was 
clear evidence of carcinogenic activity* of 1,2,3,-trichloropropane in 
male F344/N rats based on increased incidences of squamous cell 
papillomas and carcinomas of the oral mucosa and forestomach, adenomas 
of the pancreas and kidney, adenomas or carcinomas of the preputial 
gland, and carcinomas of the Zymbal's gland. Adenomatous polyps and 
adenocarcinomas of the intestine may have been related to chemical 
administration. There was clear evidence of carcinogenic activity of 
1,2,3-trichloropropane in female F344/N rats based on increased 
incidences of squamous cell papillomas and carcinomas of the oral 
mucosa and forestomach, adenomas or carcinomas of the clitoral gland, 
adenocarcinomas of the mammary gland, and carcinomas of the Zymbal's 
gland. Adenocarcinomas of the intestine may have been related to 
chemical administration.
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    *The NTP uses five categories of evidence of carcinogenic 
activity observed in each animal study: two categories for positive 
results (``clear evidence'' and ``some evidence''), one category for 
uncertain findings (``equivocal evidence''), one category for no 
observable effect (``no evidence''), and one category for studies 
that cannot be evaluated because of major flaws (``inadequate 
study'').
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    There was clear evidence of carcinogenic activity of 1,2,3-
trichloropropane in male B6C3F1 mice based on increased incidences of 
squamous cell papillomas and carcinomas of the forestomach, 
hepatocellular adenomas or carcinomas, and harderian gland adenomas. 
Squamous cell papillomas of the oral mucosa may have been related to 
chemical administration. There was clear evidence of carcinogenic 
activity of 1,2,3-trichloropropane in female B6C3F1, mice based on 
increased incidences of squamous cell carcinomas of the oral mucosa, 
squamous cell papillomas and carcinomas of the forestomach, 
hepatocellular adenomas or carcinomas, harderian gland adenomas, and 
uterine adenomas, adenocarcinomas, and stromal polyps.
    Nonneoplastic lesions associated with exposure to 1,2,3-
trichloropropane included increased severity of nephropathy in male 
rats and increased incidences of basal cell and squamous hyperplasia of 
the forestomach, acinar hyperplasia of the pancreas, renal tubule 
hyperplasia, and preputial or clitoral gland hyperplasia in male and 
female rats. Increased incidences of squamous hyperplasia of the 
forestomach and eosinophilic foci in the liver in male and female mice 
were chemical related.
    Questions or comments about the Technical Report should be directed 
to Central Data Management at P.O. Box 12233, Research Triangle Park, 
NC 27709 or telephone (919) 541-3419.
    Copies of Toxicology and Carcinogenesis Studies of 1,2,3-
Trichloropropane (CAS No. 96-18-4) in F344/N Rats and B6C3F1 Mice 
(Gavage Studies) (TR-384) are available without charge from Central 
Data Management, NIEHS, MD A0-01, P.O. Box 12233, Research Triangle 
Park, NC 27709; telephone (919) 541-3419.

    Dated: July 14, 1994.
Kenneth Olden,
Director, National Toxicology Program.
[FR Doc. 94-17454 Filed 7-18-94; 8:45 am]
BILLING CODE 4140-01-M