96-10834. National Toxicology Program; Availability of Technical Report on Toxicology and Carcinogenesis Studies of Benzethonium Chloride

[Federal Register Volume 61, Number 85 (Wednesday, May 1, 1996)]
[Notices]
[Page 19306]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-10834]



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DEPARTMENT OF HEALTH AND HUMAN SERVICES

National Toxicology Program; Availability of Technical Report on 
Toxicology and Carcinogenesis Studies of Benzethonium Chloride

    The HHS' National Toxicology Program announces the availability of 
the NTP Technical Report on the toxicology and carcinogenesis studies 
of benzethonium chloride, which is used primarily in cosmetics for its 
antimicrobial and cationic surfactant properties.
    Toxicology and carcinogenicity studies were conducted by dermal 
administration of benzethonium chloride to groups of 60 F344/N rats and 
60 B6C3F1 mice of each sex at doses of 0, 0.15, 0.5, or 1.5 mg/kg 
body weight. Benzethonium chloride was administered to rats in ethanol 
5 days per week and doses were adjusted weekly according to the average 
body weights of the groups. As many as nine rats per group were 
evaluated after 15 months. Mice received doses administered in ethanol 
and dose volumes were adjusted weekly according to average body weights 
of the groups. As many as ten mice per group were evaluated after 15 
months of chemical administration.
    Under the conditions of these 2-year dermal studies, there was no 
evidence of carcinogenic activity 1 of benzethonium chloride in 
male or female F344 rats or in male or female B6C3F1 mice.
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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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    Exposure of rats and mice to benzethonium chloride by dermal 
application in ethanol for 2 years resulted in epithelial hyperplasia 
in male and female rats and mice and sebaceous gland hyperplasia and 
ulcers in female rats at the site of application.
    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 [phone].
    Copies of Toxicology and Carcinogenesis Studies of Benzethonium 
Chloride (CAS No. 121-54-0) (TR-438) are available without charge from 
Central Data Management, NIEHS, MD E1-02, P.O. Box 12233, Research 
Triangle Park, NC 27709; telephone [phone].

    Dated: April 12, 1996.
Kenneth Olden,
Director, National Toxicology Program.
[FR Doc. 96-10834 Filed 4-30-96; 8:45 am]
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