National Toxicology Program

National Toxicology Program

Regulatory Actions for Year 1999

Environmental Protection Agency (EPA)

Notice Type Title Summary of Notice NTP Information Cited CASRN
Final Rule Diflubenzuron; Pesticide Tolerances The EPA established tolerances for residues of the insecticide diflubenzuron and its metabolites 4-chlorophenylurea and 4-chloroaniline in/on rice grain at 0.02 ppm and rice straw at 0.8 ppm.

April 19, 1999 -- 64 FR 19050
The 4-chloroaniline (PCA) metabolite was classified as a Group B2 carcinogen (probable human carcinogen) based on the results of the NTP bioassay on PCA (TR-351). The NTP bioassay and the results of several NTP mutagenicity studies on PCA discussed in the bioassay report were part of the information used to estimate dietary risk assessments. 20265-96-7
Notice Acetonitrile: Community Right-to-Know Toxic Chemical Release Reporting The EPA is denying a petition to remove acetonitrile from the list of chemicals subject to the reporting requirements under section 313 of the Emergency Planning and Community Right-to-Know Act of 1986 (EPCRA) and section 6607 of the Pollution Prevention Act of 1990 (PPA).

March 05, 1999 -- 64 FR 10597
EPA reviewed all of the available data, including the NTP Technical Report of the Toxicology and Carcinogenesis of Acetonitrile (TR-447), to conclude that acetonitrile can reasonably be anticipated to cause serious or irreversible chronic health effects in humans, including neurotoxicity and death. 75-05-8
Notice Update on the Status of the Superfund Substance-Specific Applied Research Program This Notice provides the status of ATSDR's Superfund mandated Substance-Specific Applied Research Program (SSARP). To date, 188 priority data needs have been identified for the 50 priority hazardous substances frequently found at waste sites.

January 15, 1999 -- 64 FR 2759
The ATSDR maintains an interagency agreement (IAG) with NTP to conduct toxicologic testing of substances identified at National Priority List sites.  Under this agreement, the NTP filled the toxicity priority data need for the immunotoxicology study of carbon tetrachloride.  The NTP is currently addressing reproductive toxicity data needs for chlordane, endrin, and heptachor; the bioavailability of PCB's in soil; and dose-response data for di-n-butyl phthalate.

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Food and Drug Administration (FDA)

Notice Type Title Summary of Notice NTP Information Cited CASRN
Final Rule Diflubenzuron; Pesticide Tolerances The FDA is amending the food additive regulations to provide for the safe use of 4,5-dichloro-1,2-dithiol-3-one as a slimicide in the manufacture of food-contact paper and paperboard. Although the additive itself has not been shown to cause cancer, it has been found to contain minute amounts of tetrachloroethylene, a carcinogenic impurity resulting from the manufacture of the additive

December 15, 1999 -- 64 FR 69898
The FDA used data from the NTP Carcinogenicity Study of Tetrachloroethylene (TR-311), to estimate the upper-bound limit of lifetime human risk from exposure resulting from the use of the additive. And based on its estimates of worst case exposure, the FDA concluded that there is reasonable certainty that no harm from exposure to tetrachloroethylene would result from the proposed use of the additive. 127-18-4
Final Rule Diflubenzuron; Pesticide Tolerances The FDA is issuing a final rule establishing that the over-the-counter stimulant laxative ingredients danthron and phenolphthalein are not generally recognized as safe and effective and are misbranded.

January 29, 1999 -- 64 FR 4535
After reviewing all of the available data, including the NTP phenolphthalein studies, the FDA concluded that phenolphthalein caused chromosome aberrations, cell transformation, and mutagenicity in mammalian cells and is reasonably anticipated to have human carcinogenic potential. TR 465: Toxicology and Carcinogenesis Studies of Phenolphthalein in F344/N Rats and B6C3F1 Mice (Feed Studies) Dunnick JK et al.,; Phenolphthalein Induces Thymic Lymphomas Accompanied By Loss Of The P53 Wild Type Allele In Heterozygous P53-Deficient (+/-) Mice,; Toxicologic Pathology 1997, 25(6): 533-540.

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NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.