Despite industry opposition, on May 20, 2016, the Office of Environmental Health Hazard Assessment (OEHHA) added three commonly used pesticides, malathion (CAS No. 121-75-5), parathion (CAS No. 56-38-2), and tetrachlorvinphos (CAS No. 22248-79-9), to the Prop 65 list. OEHHA also stated that it will publish a decision about whether to list another major pesticide, glyphosate (CAS No. 1071-83-6), at a later date.

Malathion is an organophosphate insecticide that is widely used in agriculture, residential landscaping, residential insect control, and public health programs. Parathion is an organophosphate insecticide and acaricide which is primarily used on plants bearing cotton, fruit, vegetables, nuts, and wheat. Tetrachlorvinphos is an organophosphate insecticide mainly used to kill fleas and ticks. It is found primarily in dermal and feed-through insect control treatment for livestock and in pet flea and tick collars, powders, and sprays.

OEHHA listed the three pesticides despite significant industry opposition, including 230 comments. It rejected eight comments via a detailed response when it listed the pesticides.

Prop 65 warnings will be required for malathion, parathion, and tetrachorvinphos starting on May 20, 2017. OEHHA intends to propose a safe harbor level for malathion prior to that date.

Notice of Intent to List Bromodichloroacetic Acid

On May 27, 2016, OEHHA published a Notice of Intent to List Bromodichloroacetic Acid (CAS No. 71133-14-7), based on a 2015 National Toxicology Program report finding that the chemical causes cancer. Bromodichloroacetic acid is a byproduct formed after water is disinfected with halogenated oxidants, usually chlorine. Comments are due by June 27, 2016.