California’s Office of Environmental Health Hazard Assessment (OEHHA) issued a safe use determination (SUD) for the use of diisononyl phthalate (DINP) in certain roofing materials and applications.
OEHHA determined that a Proposition 65 warning for the installation of single-ply polyvinyl chloride (PVC) roofing membranes is not required. It found that the reviewed exposure scenario to DINP, during installation, resulted in an excess cancer risk of less than one in 100,000, and an exposure to 83 micrograms of DINP per day, the equivalent of
57 percent of the proposed No Significant Risk Level (NSRL) for the substance.
The SUD calls for the PVC roofing membrane products with a nominal finished thickness of between 1.016 to 2.438 mm, containi
ng no more than 15 percent DINP and heated to surface temperatures up to and including 210ºC during installation.
The agency called for public comments on the proposed SUD in April and May, but none were submitted.
DINP is a plasticizer from the phthalate family of chemicals which make plastic materials more flexible.
DINP was listed by the state’s Carcinogen Identification in December 2013. The listing was subsequently challenged by the American Chemistry Council, which sued OEHHA in a declaratory relief lawsuit that was rejected by a Sacramento Superior Court Judge.
ACC subsequently filed an appeal which is pending.
The SUD was developed at the request of the Chemical Fabrics & Film Association (CFFA) earlier this year. It applies solely to CFFA’s PVC membrane roofing products.
Safe Use Determinations have been used sparingly by industry, but recent changes to the regulations have encouraged some companies to seek a determination, now that the risk of litigation to the requesting party is diminished.