Metribuzin

CASRN 21087-64-9 | DTXSID6024204

IRIS Summary (PDF) (14 pp, 117 K)
Status: EPA announced in a 2004 Federal Register Notice that chemicals used as pesticides would not be re-assessed by the IRIS Program. This entry in the IRIS database is preserved at the request of EPA program and regional offices. Additional toxicological information may be found under "Other EPA Information."

On this page:

System	RfD (mg/kg-day)	Basis	PoD	Composite UF	Confidence
Hepatic, Urinary, Other	2.5 x 10 ^-2	Liver and kidney effects, decreased body weight, mortality	NOEL : 2.5 mg/kg-day	100	Medium

Not assessed under the IRIS Program.

Weight of Evidence for Cancer (PDF) (14 pp, 117 K) Last Updated: 12/01/1993

WOE Characterization	Framework for WOE Characterization
D (Not classifiable as to human carcinogenicity)	Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986)

Basis:

No human data and inadequate evidence ffom animal bioassays. Metribuzin did not increase the incidence of tumors in a lifetime dietary study using CD-1 mice when compared with both concurrent and historic controls. In a 2-year feeding study in Wistar rats, no significant differences in neoplastic findings between the test and control groups were found. Short-term studies in bacteria and mammalian systems suggest that metribuzin is not mutagenic.
This may be a synopsis of the full weight-of-evidence narrative.

Not assessed under the IRIS Program.

Not assessed under the IRIS Program.

Additional EPA toxicity information may be available by visiting the following sites:

Human Health Benchmarks for Pesticides (HHBP). This database provides human health benchmarks for pesticides that may be present in drinking water.
Office of Pesticide Programs Pesticide Chemical Search. This database provides links to health effects information and registration status for pesticides.
Chemistry Dashboard. This database provides information on chemical structures, experimental and predicted physicochemical, and toxicity data.