Proposition 65 Assessments
Since the early 1990's, we have provided technical expertise to parties involved in California Proposition 65 issues and assessments. Such assessments can be used by parties considering filing claims of significant risk to health, as well as by parties defending against such claims. We are expert at assessing all relevant behaviors, scenarios, and routes of exposure — inhalation, ingestion, and absorption across skin. For each scenario and route of exposure, we search for empirical data (either on the chemical of interest or on reasonable surrogate chemicals), determine whether additional test data are desired and/or required, and develop and apply mathematical models to make best estimates of doses to consumers, workers, and others. Often, these models — whether of the fate and transport of chemicals in indoor air, for example, or of chemical-uptake by people exposed in various ways — are not straightforward. Modeling dermal exposure from a cosmetic, lotion, or aqueous solution, for example, typically involves approximate solutions of a differential equation for diffusion through skin, combined with analysis of, and comparison with, a large experimental database on dermal permeation of chemicals. Our ability to use and document such techniques is central to our producing high-quality assessments and reports.
We are also skilled in analyzing and extrapolating dose-response data in order to comment intelligently and compellingly on proposed "no significant risk levels" (NSRLs) and "maximum allowable dose levels" (MADLs).
Examples of our Proposition 65 reports are available at the links below.