Methidathion

CASRN 950-37-8

Notice - This site contains archived material

  • Status: The IRIS Assessment for the pesticide Methidathion has been archived and is not being reassessed by IRIS at this time.
  • Archived IRIS Summary (PDF) (10 pp, 103 K)
  • Archive Disclaimer: The IRIS Program has archived a number of IRIS entries for pesticides that have been assessed more recently by EPA's Pesticide Program. The IRIS program announced in 2004 that chemicals that are solely used as pesticides would not be re-assessed.

Information from EPA's Pesticide Program


Additional toxicity information is available from EPA's Pesticide Program, including the following:

Health Hazard Assessments for Effects Other than Cancer


This data is archived and for historical reference only. Please refer to the Pesticide Program Toxicity Value.

Reference Dose for Oral Exposure (RfD) (PDF) (10 pp, 103 K) archived on: 07/15/2016

RfD (mg/kg-day) System Basis PoD Composite UF Confidence
1 x10-3 Hepatic Liver toxicity NOEL : 1 x10-1
mg/kg-day
100 High

Reference Concentration for Inhalation Exposure (RfC) (PDF) (10 pp, 103 K) archived on: 07/15/2016
Not assessed under the IRIS Program.

Cancer Assessment


Weight of Evidence for Cancer (PDF) (10 pp, 103 K) archived on: 07/15/2016

WOE Characterization Framework for WOE Characterization
C (Possible human carcinogen) Guidelines for Carcinogen Risk Assessment (US EPA, 1986)
Basis:
  • Increased incidence of liver adenomas, carcinomas, and combined adenomas and carcinomas in male mice. There was no shortening of time to tumor. Short-term tests and structure/activity study were not supportive of a higher classification.
  • This may be a synopsis of the full weight-of-evidence narrative.

Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (10 pp, 103 K)

Not assessed under the IRIS Program.

Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure (PDF) (10 pp, 103 K)

Not assessed under the IRIS Program.

You will need Adobe Reader to view some of the files on this page. See EPA’s PDF page to learn more.