Notice of Intent to List: Tetrachlorvinphos, Parathion, Malathion, Glyphosate

The California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) intends to list the chemicals identified in the table below as known to the state to cause cancer under the Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65¹). This action is being proposed pursuant to the “Labor Code” listing mechanism² . OEHHA has determined that tetrachlorvinphos, parathion, malathion, and glyphosate meet the criteria for listing by this mechanism.

* The International Agency for Research on Cancer (IARC) indicates the following chemicals are “also relevant: 38641-94-0 (glyphosate-isopropylamine salt) 40465-66-5 (monoammonium salt) 69254-40-6 (diammonium salt) 34494-03-6 (glyphosate-sodium) 81591-81-3 (glyphosate-trimesium)” (IARC, 2015b), because these salts dissociate to free glyphosate.

Background on listing by the Labor Code mechanism: Health and Safety Code section 25249.8(a) incorporates California Labor Code section 6382(b)(1) into Proposition 65. The law requires that certain substances identified by the International Agency for Research on Cancer (IARC) be listed as known to cause cancer under Proposition 65. Labor Code section 6382(b)(1) refers to substances identified as human or animal carcinogens by IARC. As the lead agency for the implementation of Proposition 65, OEHHA evaluates whether a chemical’s listing is required by Proposition 65.

OEHHA’s determination: Tetrachlorvinphos, parathion, malathion, and glyphosate each meet the requirements for listing as known to the state to cause cancer for purposes of Proposition 65.

IARC has published on its website a list entitled “Agents classified by the IARC Monographs, Volume 1-112" (IARC, 2015a) and the glyphosate monograph in Volume 112 of the IARC Monographs series (IARC, 2015b). IARC concludes that malathion and glyphosate are classified in Group 2A (“probably carcinogenic to humans”) and that tetrachlorvinphos and parathion are classified in Group 2B (“possibly carcinogenic to humans”). IARC concludes that there is sufficient evidence of carcinogenicity in experimental animals for tetrachlorvinphos, parathion, malathion, and glyphosate (Guyton et al., 2015; IARC, 2015a & b).

Opportunity for comment: OEHHA is providing this opportunity to comment as to whether the chemicals identified above meet the requirements for listing as causing cancer specified in Health and Safety Code section 25249.8(a) and Labor Code section 6382(b)(1). Because these are ministerial listings, comments should be limited to whether IARC has identified the specific chemical or substance as a known or potential human or animal carcinogen. Under this listing mechanism, OEHHA cannot consider scientific arguments concerning the weight or quality of the evidence considered by IARC when it identified these chemicals and will not respond to such comments if they are submitted.

Written comments must be received by 5:00 p.m. on Monday, October 5, 2015 to be considered. We encourage you to submit comments in electronic form, rather than in paper form. Comments transmitted by e‑mail should be addressed to P65Public.Comments@oehha.ca.gov, and should include “NOIL” and the chemical name in the subject line. Comments submitted in paper form may be mailed, faxed, or delivered in person to the address below.

Note: the comment period for Parathion, Malathion and/or Glyphosate has been extended to October 20, 2015.

Mailing Address: Ms. Esther Barajas-Ochoa
Office of Environmental Health Hazard Assessment
P.O. Box 4010, MS-19B
Sacramento, California 95812-4010
Fax: (916) 323-2265

Street Address: 1001 I Street
Sacramento, California 95814

Comments received during the public comment period will be posted on the OEHHA web site after the close of the comment period.

If you have any questions, please contact Esther Barajas-Ochoa at Esther.Barajas-ochoa@oehha.ca.gov or at (916)445-6900.