[Federal Register Volume 59, Number 10 (Friday, January 14, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-909]


[[Page Unknown]]

[Federal Register: January 14, 1994]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES
 

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

    The HHS' National Toxicology Program announces the availability of 
the NTP Technical Report on the toxicology and carcinogenesis studies 
of acetaminophen, which is a widely consumed analgesic found in several 
nonprescription pharmaceuticals.
    Two-year toxicology and carcinogenesis studies were conducted by 
administering to both sexes of rats and mice doses of 0, 600, 3,000, or 
6,000 ppm acetaminophen in feed for 104 weeks.
    Under the conditions of these 2-year feed studies, there was no 
evidence of carcinogenic activity\1\ of acetaminophen in male F344/N 
rats that received 600, 3,000, or 6,000 ppm. There was equivocal 
evidence of carcinogenic activity of acetaminophen in female F344/N 
rats based on increased incidences of mononuclear cell leukemia. There 
was no evidence of carcinogenic activity of acetaminophen in male and 
female B6C3F1 mice that received 600, 3,000, or 6,000 ppm.
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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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    Nonneoplastic lesions associated with exposure to acetaminophen 
included increased severity of nephropathy and increased incidences of 
renal tubule hyperplasia and parathyroid hyperplasia in male rats, 
increased severity of nephropathy in female rats, and increased 
incidences of thyroid follicular cell hyperplasia in male and female 
mice.
    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 Acetaminophen 
(CAS No. 103-90-2) in F344/N Rats and B6C3F1 Mice (Feed Studies) (TR-
394) 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: January 7, 1994.
Kenneth Olden,
Director, National Toxicology Program.
[FR Doc. 94-909 Filed 1-13-94; 8:45 am]
BILLING CODE 4140-01-M