The latest front in the ever-expanding Proposition 65 enforcement battle: plastic packaging. Since the start of the year, dozens of notices of violation have been filed, not for actual products, but for the packaging in which they are wrapped.

The allegations contained in this latest series of Prop 65 “60 day notices” involve phthalates, primarily DEHP, in various types of plastic wraps and product packaging. While high levels of some phthalates may be found in such packaging, the cases raise serious questions of whether “average daily exposure” to the typical user would potentially result in exposure levels that require a warning (i.e., exceed the established “safe harbor levels” for DEHP of 310 µg/day for cancer risk and 410 µg/day for developmental effects). If packaging is disposable, then exceeding these thresholds seems unlikely. If it is reusable, then factors such as the frequency and duration of contact should be examined.

A science-based exposure assessment, which can be performed at a relatively modest cost, can be very helpful in answering these questions and providing support for a robust legal defense. Faced with such an analysis, founded in conservative and very defensible exposure assumptions, plaintiffs may decide that it is best to withdraw the notice of violation and move on to “lower hanging fruit.” This approach has proven successful in some recent Prop 65 packaging cases.