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” in December 2013. Although this listing goes against the weight of scientific evidence which has found that the thoroughly studied plasticizer does not pose any risk to human health at typical exposure levels, manufacturers selling to the state of California must still be compliant with the state’s labeling requirement.
Prop 65 is not a ban or restriction of use for the listed substances. Instead it requires anyone doing business in California to add a Prop 65 warning label a product if human exposure to a listed substance in the product is expected to be above a level the “Safe Harbor” limit that has been determined by the state. The Safe Harbor Level is also known as the No Significant Risk Level (NSRL) for chemicals listed as “known to cause cancer”. The NSRL is defined as the level of exposure that would result in not more than one excess case of cancer in 100,000 individuals exposed to the substance over a 70-year lifetime.
If your product’s exposure is at or below the NSRL, it does NOT require a Prop 65 warning label. OEHHA has set the NSRL of DINP at 146 micrograms per day effective April 1, 2016.
How do you know if your product’s human exposure to DINP is above the NSRL? Exposure can be determined with a number of calculations, and the American Chemistry Council (ACC) has developed a workbook with guidance and examples on how to estimate potential product exposures to DINP. In workbook helps users determine a “worst case” exposure level by considering three ways of exposure: direct skin absorption by touching the product, inhalation by breathing air containing DINP, and hand-to-mouth oral ingestion of DINP. Examples of scenarios that you might use the workbook for include walking barefoot on vinyl flooring, wearing PVC gloves, or installing PVC wires in the home.
What happens if you do not comply with Prop 65? Prop 65 is mostly enforced through civil lawsuits brought by the California Attorney General, certain district and city attorneys, or private parties acting in the public interest. If the business is found to be violating Prop 65, they will be ordered to comply with the law and could face civil penalties of up to $2,500 per day for each violation. Because exposure levels in consumer products containing DINP can be difficult to determine, the workbook could provide a good framework for any legal arguments on the subject.
For more information about the DINP, Prop 65, and the workbook, visit the ACC website.