On April 22, 2016, OEHHA added styrene as a carcinogen to the Proposition 65 list. In a separate regulatory proceeding, OEHHA also is proposing a “No Significant Risk Level” (NSRL) for styrene of 27 micrograms per day. Comments on the proposed NSRL must be submitted no later than June 6, 2016.
The NSRL is the level of exposure for a carcinogen, above which a Proposition 65 warning is required. (The equivalent level for a Proposition 65 reproductive toxicant is the “Maximum Acceptable Dose Level,” or MADL.) OEHHA’s proposal is surprising in that the agency’s promulgation of NSRLs and MADLs historically has lagged far behind the agency’s chemical listings, leaving businesses to develop their own NSRLs and MADLs at significant cost. Worse, where a business has undertaken the resource-intensive burden of calculating an NSRL or MADL to evaluate its own potential warning obligations, a plaintiff may dispute the calculation of the warning level and the assumptions underlying it — rendering the exercise not only expensive, but, in practical effect, worthless to avoid an enforcement action the first place. Apparently recognizing this difficulty, OEHHA recently has been promulgating NSRLs and MADLs at a more rapid pace.