Home > Insights > Publications > Prop 65: 9 chemicals added to California’s list for required warnings

Prop 65: 9 chemicals added to California’s list for required warnings

Gary Wexler January 11, 2018

During 2017, the California Office of Environmental Health Hazard Assessment (OEHHA) added nine compounds to its list of chemicals that product manufacturers are required by law to disclose to consumers. 

The disclosure requirement originates with the Safe Drinking Water and Toxic Enforcement Act of 1986, commonly known as Proposition 65 (Prop 65), and applies to chemicals that the State of California claims cause cancer, birth defects or other reproductive harm. (Note: This article does not discuss or take a position on the propriety, or lack thereof, of OEHHA’s regulatory standards for chemicals; it simply reports on the recent actions taken by the administrative agency.)

The chemicals that appear on the list are regulated under Prop 65, but the law’s warning requirements do not apply for a given chemical until 12 months after it is listed. Thus, chemicals added to the list during 2017 will not require compliant Prop 65 warnings until their effective dates in 2018. 


Prop 65 provides that a person (defined as including an individual, corporation, company and partnership) in the course of doing business is required to warn an individual before exposing that individual to a chemical on the list, unless an exemption applies. One such exemption is the 12-month period following listing of that chemical. 

The warning must be "clear and reasonable," meaning that the warning must 1) clearly state that the chemical involved is known to cause cancer, birth defects or other reproductive harm; and 2) be given in such a way that it will effectively reach the individual before he or she is exposed to that chemical. 

OEHHA previously adopted new Prop 65 regulations that materially change the existing requirements for, among other things, the content and method of transmission of "clear and reasonable" warnings. Those changes become effective on August 30, 2018. 

A person found in violation of Prop 65 is subject to civil penalties of up to $2,500 per day for each violation and an injunction against selling or offering for sale in California the violating product. A violator may also be required to pay the attorneys’ fees of the person or entity that served the Prop 65 notice, whether the alleged violation is resolved by court action or settlement. 

The Prop 65 list of chemicals was most recently updated on November 10, 2017. The nine chemicals added during 2017 and the dates listed are as follows (as a reminder, the warning requirement will apply to each chemical 12 months after its listing date):

Chemical Type of Toxicity Date Listed
N,N-Dimethylformamide cancer $27-Oct-17
Glyphosate cancer $7-Jul-17
2-Mercaptobenzothiazole cancer 27-Oct-17
pentabromodiphenyl ether mixture [DE-71 (technical grade)] cancer 7-Jul-17
Perfluorooctane sulfonate (PFOS) developmental 10-Nov-17
Perfluorooctanoic acid (PFOA) developmental 10-Nov-17
Pertuzumab developmental 27-Jan-17
Tetrabromobisphenol A cancer 27-Oct-17
Vismodegib developmental, female, male 27-Jan-17

Gary Wexler is a partner in the firm's litigation department with a practice that focuses on real estate. You can reach him at (310) 282-9470 or gwexler@thompsoncoburn.com.