On October 6, 2020, the California Developmental and Reproductive Toxicant Identification Committee (DARTIC) announced it will be meeting on December 11, 2020, to discuss the possible developmental and reproductive toxicity (DART) of 22 chemical substances and chemical groups, including glyphosate and its salts, and three neonicotinoid pesticides (acetamiprid, clothianidin, and imidacloprid).  DARTIC is composed of scientists who advise California’s Office of Environmental Health Hazard Assessment (OEHHA) on the prioritization of chemicals for potential Proposition 65 (Prop 65) listing and identification of chemicals that have been shown through scientifically valid testing according to generally accepted principles to cause reproductive toxicity.

Public comments on the 22 substances will be accepted until November 16, 2020, and OEHHA will forward those comments to DARTIC members prior to its meeting. 

The full list of chemicals and chemical groups that DARTIC will discuss are:

• Benzophenone-3;

• Bisphenol S;

• Diazinon;

• Diethylphthalate;

• Domoic acid;

• Glyphosate and its salts;

• Manganese;

• Neonicotinoid pesticides;

  • Acetamiprid;

  • Clothianidin;

  • Imidacloprid;

  • Thiamethoxam;

• Parabens;

  • Butyl paraben;

  • Isobutyl paraben;

  • Methyl paraben;

  • Propyl paraben;

• Per- and polyfluorinated substances (PFAS);

  • Perfluorodecanoic acid (PFDA);

  • Perfluorohexanesulfonic acid (PFHxS);

  • Perfluorononanoic acid (PFNA);

  • Perfluoroundecanoic acid (PFUnDA);

• Titanium dioxide nanoparticles;

• Vinpocetine; and

• Zearalenone.

OEHHA’s document, Prioritization: Chemicals Identified for Consultation with the Developmental and Reproductive Toxicant Identification Committee, presents information on these chemicals or chemical groups for DARTIC’s consideration.  Specifically, OEHHA states:  “For each, an initial, abbreviated appraisal of the scientific information identified through the screening-level literature search and the preliminary toxicological evaluation is presented.”  With regard to glyphosate and its salts, OEHHA provides “a brief overview of the relevant studies published within the last five years and those included in the Toxicological Profile for Glyphosate by ATSDR (ATSDR 2020) that were identified during the preliminary toxicological evaluation.”

No listing decisions will be made by DARTIC at the December meeting.  If OEHHA moves forward to propose to list any substances, it will separately issue a notice and seek public comments.

Discussion

The fact that OEHHA is seeking DARTIC’s review of glyphosate is particularly interesting, as glyphosate is already listed under Prop 65 based on a finding that glyphosate is a chemical known to cause cancer.  That listing is in jeopardy, however, based on a June 2020 court decision that prohibits OEHHA from requiring Prop 65 warnings because the basis for the listing, a determination by the International Agency for Research on Cancer (IARC) that the glyphosate is “probably” carcinogenic to humans, is not consistent with the findings of the U.S. Environmental Protection Agency (EPA) and other agencies.  Additional information regarding glyphosate’s Prop 65 listing is available here.  If OEHHA is not successful in its appeal of the court’s ruling and is successful in listing glyphosate based on its potential to cause developmental and reproductive toxicity effects, the result would be a new basis upon which to impose Prop 65 warning requirements.  At the same time, EPA’s registration review of glyphosate encompasses, in EPA’s view, a health risk assessment, which includes a pesticide’s potential risks of developmental and reproductive effects.  As a result, it is not clear if EPA’s arguments that its FIFRA labeling authority prohibits Prop 65 warnings also would apply to its registration review of health risks, which includes possible developmental and reproductive effects.