California’s Office of Environmental Health Hazard Assessment (OEHHA) has finalized the listing of “cannabis (marijuana) smoke” and delta-9-tetrahydrocannabinol (THC) as reproductive toxins under Proposition 65.

The listings are effective as of January 3, 2020. Under Prop 65, enforcement of the warning requirements begins one year after listing, which, in this case, gives businesses until January 3, 2021, to determine if warnings are required for their products and, if so, to post a proper warning (such as on a product label, website page, and/or shelf sign, among other options).

As discussed in an earlier post, marijuana smoke has been listed as a Prop 65 carcinogen since 2009. In December, the Developmental and Reproductive Toxicant Identification Committee (DARTIC) of OEHHA’s Science Advisory Board — in its official capacity as the “state’s qualified experts” — voted in support of listing as a reproductive toxin based on a determination that cannabis smoke and THC “have been shown to cause reproductive toxicity based on the developmental endpoint.”

While Prop 65 warnings already appear on many marijuana-based products, the new listing of cannabis smoke is likely to require businesses to amend their warnings to address both cancer and reproductive toxicity. Failure to do so can give plaintiff groups an opening to challenge the adequacy of the current warning statement for these products.

The THC listing brings a broader range of marijuana products into the Prop 65 world, namely, cannabis products that do not expose users to smoke, such as edibles, beverages, or vape cartridges.

Plaintiff groups have been extremely active on the marijuana front in the last year or so, filing hundreds of Prop 65 notices of violations against businesses for failure to provide a required warning.

More information on the new listings can be found on OEHHA’s website here.