Proposition 65 - Risk Assessment

Under Proposition 65, “clear and reasonable warnings” must be applied to certain products and discharges to possibly potable water, based on risk to the public. Estimating the degree of risk is therefore essential, and depends partly on levels of exposure to the products or discharges. Levels of exposure are frequently estimated by calculation, using mathematical models that predict chemical distribution and dissipation. However, since most exposure scenarios are not specifically set out in regulation under Proposition 65, proper guidance from experts with an intimate knowledge of the law is fundamental to protecting a product from potential litigation under the Act.

Enforcement under Proposition 65 is by litigation, not by Agency decision like most environmental statutes. Therefore, exposure levels and penalties can be negotiated with plaintiffs and decided by courts if negotiations fail. Successful risk assessments under Proposition 65 follow the history of analogous litigation under the Act.

TSG’s consultants provide the knowledge and experience to help companies make sound decisions and avoid litigation. Our risk assessments may utilize:

▲ Use of chemicals listed under Proposition 65 as a basis for determining relevant exposures or the Safe Harbor Level in the absence of a default value established by the Office of Environmental Health Hazard Assessment  (OEHHA);

▲ Conservative assumptions, calculation models and absence of surrogate data or product data; and

▲ Use of presumptions that are in-line with previous actions and litigation under Proposition 65.

Our scientist’s risk assessments generate an exposure level that we use to calculate a value TSG terms the “Margin of Comfort” (Exposure Level ÷ Safe Harbor Level) for protection from litigation under Proposition 65. Margins below one are subject to warnings or discharge prohibitions, margins above one show that warnings or discharge prohibitions are not required, and margins in between require a variety of different approaches, depending on many factors.

TSG provides companies with:

▲ Expertise in conducting Proposition 65 risk assessments and experience with plaintiff's positions and tactics;

▲ Guidance and documentation to deter litigation; and

▲ Documentation to support customer requests.

TSG’s staff has been conducting risk assessments under Proposition 65 since the first week after voters approved the Act in November 1986. TSG’s consultants provide underlying documentation to deter litigation and satisfy client requests. We also assist clients by assessing products under notice of potential litigation and negotiating favorable outcomes with a plaintiff.