As of January 2, 2021, any product sold in California which contains a measurable amount of Δ9-tetrahydrocannabinol (Δ9-THC), familiarly known as THC, will be subject to the warning requirement of California’s Safe Drinking Water and Toxic Enforcement Act of 1986, popularly known as Proposition 65. See Proposition 65.  This requirement is based upon a determination that marijuana smoke and THC in any form are teratogens, or developmental toxicants.

THC is a psychoactive cannabinoid, one of many cannabinoids contained in cannabis. Another cannabinoid, cannabidiol, known CBD and which is not psychoactive, has become wildly popular and is contained in a multitude of products making an assortment of wellness claims. Since industrial hemp, the primary source of CBD, contains trace amounts of THC (legally at a concentration of 0.3% or less), all CBD products derived from hemp are likely to contain a trace amount of THC.

At a December 11, 2019, meeting the Developmental and Reproductive Toxicant Identification Committee (“DARTIC”) of California’s Office of Environmental Health Hazard Assessment (“OEHHA”) adopted an amendment to the list of chemicals subject to notice under the act adding marijuana smoke and THC.  California Notice of Proposition 65 Listing of Marijuana Smoke and THC.  The listing was premised on a review prepared by OEHHA’s Reproductive and Cancer Hazard Assessment Branch. See Evidence on the Developmental Toxicity of Cannabis (Marijuana) Smoke and THC.

Proposition 65 warnings for products may take the form either of a warning on the label of the product, or a posted notice at the point of sale, alerting the customer (or person exposed to the product) that the product contains a teratogen. Next year CBD products sold in California will be subject to the  warning requirement. Such a warning on a CBD product with wellness claims, whether on the product label or a point-of-sale notice, stating that the product contains a teratogen, will certainly create a paradox for marketers of wellness products. Presumably the marijuana smoke warning will apply to the sale of marijuana flower, but such a warning would likely pose less of an obstacle to its sale. Social lounges where marijuana is smoked will likely follow the practice of establishments serving alcohol and post a warning sign at their entrances,