In December 2013, the California Office of Environmental Health Hazard Assessment (OEHHA) added diisononyl phthalate (DINP) to California's Proposition 65 list as “known to the State to cause cancer” despite the weight of scientific evidence indicating that DINP should not be listed on Prop 65.
Currently, there are more than 800 substances on the Prop 65 list, including food ingredients and common household products, naturally occurring substances, ethyl alcohol in alcoholic beverages, aspirin and many prescription drugs. Prop 65 requires anyone doing business in California to label a product unless the anticipated human exposure to a listed substance in the product will not pose a significant risk of cancer or reproductive harm. Labeling requirements for DINP went into effect on December 20, 2014.
Under Prop 65, it is the responsibility of California businesses to determine whether a product warning is required. OEHHA has the authority, but is not required, to establish “safe harbor levels” for Prop 65 substances. For carcinogens, the safe harbor level is referred to as a “no significant risk level” (NSRL). Safe harbor levels have been established by OEHHA for only about 1/3 of the listed chemicals.