[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: 94-17451]
[[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 2,3-Dibromo-1-Propanol
The HHS' National Toxicology Program announces the availability of
the NTP Technical Report on the toxicology and carcinogenesis studies
of 2,3-Dibromo-1-propanol, a colorless liquid that has been used as a
flame retardant, as an intermediate in the preparation of the flame
retardant tris(2,3-dibromopropyl) phosphate, and as an intermediate in
the manufacture of pesticides and pharmaceutical preparations.
Toxicology and carcinogenicity studies were conducted by applying
2,3-dibromo-1-propanol (approximately 98% pure) in ethanol to the
subscapular area of the skin to groups of 50 F344/N rats and 50
B6C3F1 mice 5 days per week for 48 to 51 weeks (male rats), 52 to
55 weeks (female rats), 36 to 39 weeks (male mice), or 39 to 42 weeks
(female mice). Rats received dermal applications of 0, 188, or 375 mg/
kg 2,3-dibromo-1-propanol; mice received dermal applications of 0, 88,
or 177 mg/kg.
Originally planned to last for 2 years, the chronic study in rats
was terminated early because of reduced survival in the high-dose
groups related to chemical induced neoplasms. The chronic study in mice
was also terminated early because of the detection of antibodies to
lymphocytic choriomeningitis virus in sentinel mice.
Under the conditions of these long-term dermal studies, there was
clear evidence of carcinogenic activity* of 2,3-dibromo-1-propanol in
the male F344/N rats based on increased incidences of neoplasms of the
skin, nose, oral mucosa, esophagus, forestomach, small and large
intestine, Zymbal's gland, liver, kidney, tunica vaginalis, and spleen.
There was clear evidence of carcinogenic activity of 2,3-dibromo-1-
propanol in female F344/N rats based on increased incidences of
neoplasms of the skin, noses, oral mucosa, esophagus, forestomach,
small and large intestine, Zymbal's gland, liver, kidney, clitoral
gland, and mammary gland. There was clear evidence of carcinogenic
activity of 2,3-dibromo-1-propanol in female B6C3F1 mice based on
increased incidences of neoplasms of the skin and the forestomach. The
increased incidences of alveolar/bronchiolar adenomas in female mice
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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In rats, 2,3-dibromo-1-propanol caused increased incidences of
hyperkeratosis in the skin, forestomach, and esophagus, epithelial
dysplasia in the nose, pleomorphism and basophilic and clear cell
changes in the liver, and nuclear enlargement in the kidney. There was
also chemical-related increases in the incidences of forestomach ulcers
and acanthosis, angiectasis in the liver, and renal hyperplasia in male
rats and epithelial dysplasia of the forestomach and bile duct
hyperplasia in the liver in famale rats. Chemical-related increases
occurred in the incidences of hyperplasia in the skin, epithelial
dysplasia of the forestomach, bronchiolar epithelial pleomorphism and
hyperplasia in male and female mice and in the incidence of
eosinophilic cytoplasmic change in the liver in males.
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 2,3-Dibromo-1-
Propanol (CAS No. 96-13-9) in F344/N Rats and B6C3F1 Mice (Dermal
Studies) (TR-400) 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 13, 1994.
Kenneth Olden,
Director, National Toxicology Program.
[FR Doc. 94-17451 Filed 7-18-94; 8:45 am]
BILLING CODE 4140-01-M
