[Federal Register Volume 61, Number 242 (Monday, December 16, 1996)]
[Notices]
[Page 66056]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-31779]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES

National Toxicology Program; Availability of Technical Report on 
Toxicology and Carcinogenesis Studies of 2,2-Bis(Bromomethyl)-1,3-
Propanediol

    The HHS' National Toxicology Program announces the availability of 
the NTP Technical Report on the toxicology and carcinogenesis studies 
of 2,2-bis(bromomethyl)-1,3-propanediol which is used as a fire 
retardant in unsaturated polyester resins, in molded products, and in 
rigid polyurethane foam.
    Toxicology and carcinogenicity studies were conducted by 
administering 2,2-bis(bromomethyl)-1,3-propanediol to groups of 60 
F344/N rats of each sex in feed at exposures of 0, 2,500, 5,000, or 
10,000 for 104 to 105 weeks. Nine or ten control animals and five to 
nine animals from each of the continuous-exposure groups were evaluated 
at 15 months. Additional male rats added for a ``stop-study'' received 
0 or 20,000 ppm for 3 months, after which animals received undosed feed 
for the remainder of the 2-year study. Groups of 60 B6C3F1 mice of 
each sex received 0, 312, 625, or 1,250 ppm in feed for 104 to 105 
weeks. Eight to 10 animals were evaluated at 15 months.
    Under the conditions of these 2-year feed studies, there was clear 
evidence of carcinogenic activity\1\ of 2,2-bis(bromomethyl)-1,3-
propanediol (FR-1138) in male F344/N rats based on increased 
incidences of neoplasms of the skin, subcutaneous tissue, mammary 
gland, Zymbal's gland, oral cavity, esophagus, forestomach, small and 
large intestines, mesothelium, urinary bladder, lung, thyroid gland, 
and seminal vesicle, and the increased incidence of mononuclear cell 
leukemia.
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    \1\ 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 2,2-
bis(bromomethyl)-1,3-propanediol in female F344/N rats based on 
increased incidences of neoplasms of the oral cavity, esophagus, 
mammary gland, and thyroid gland. There was clear evidence of 
carcinogenic activity of 2,2-bis(bromomethyl)-1,3-propanediol in male 
B6C3F1 mice based on increased incidences of neoplasms of the 
harderian gland, lung, and kidney.
    There was clear evidence of carcinogenic activity of 2,2-
bis(bromomethyl)-1,3-propanediol in female B6C3F1 mice based on 
increased incidences of neoplasms of the harderian gland, lung, and 
subcutaneous tissue. Slight increases in the incidences of neoplasms of 
the pancreas and kidney in male rats; forestomach in male mice; and 
forestomach mammary gland, and circulatory system in female mice may 
have also been related to treatment.
    Exposure of male and female rats to 2,2-bis(bromomethyl)-1,3-
propanediol was associated with alveolar/bronchiolar hyperlasia in the 
lung (males only); focal atrophy, papillary degeneration, transitional 
epithelial hyperplasia (pelvis), and papillary epithelial hyperplasia 
in the kidney; follicular cell hyperplasia in the thyroid gland (males 
only); hyperplasia in the seminal vesicle and pancreas (males only); 
mucosal hyperplasia in the forestomach (males only); and urinary 
bladder hyperplasia (males only). Exposure of mice to 2,2-
bis(bromomethyl)-1,3-propanediol was associated with hyperplasia of the 
alveolar epithelium in females.
    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 2,2-
Bis(bromomethyl)-1,3-propanediol (CAS No. 3296-90-0) (TR-452) are 
available without charge from Central Data Management, NIEHS, MD E1-02, 
P.O. Box 12233, Research Triangle Park, NC 27709; telephone (919) 541-
3419.

    Dated: November 13, 1996.
Samuel H. Wilson,
Deputy Director, NIEHS.
[FR Doc. 96-31779 Filed 12-13-96; 8:45 am]
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