[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
