Weed Killer Ingredient to be Added to California Prop 65 List
California’s Office of Environmental Health Hazard Assessment announced March 28 that it is adding glyphosate, the active ingredient in a number of weed killers, to the list of chemicals known to the state to cause cancer for purposes of the Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65). OEHHA states that the effective date of this listing will depend on the outcome of a request for a stay in a lawsuit challenging the agency’s ability to list this chemical.
Prop 65 does not ban or restrict the use of listed chemicals. Instead, beginning one year after a chemical is added to the Prop 65 list businesses are required to provide a “clear and reasonable” warning before knowingly and intentionally exposing anyone to that chemical unless they can show that the anticipated exposure level will not pose a significant risk of cancer or is significantly below levels observed to cause birth defects or other reproductive harm. This warning can be given in several ways; e.g., labeling a consumer product.
OEHHA is accepting comments through May 22 on a proposed regulatory safe harbor level for glyphosate of 1100 micrograms per day. No warning would be required for exposures to glyphosate below this level, but businesses with 10 or more employees who cause exposures above this level might need to provide warnings. OEHHA does not know at this time which products and exposures would exceed the safe harbor level and require warnings.