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Understanding Exposure Levels Under Prop 65

Proposition 65 is often misinterpreted as banning certain chemicals that are known to cause cancer or reproductive harm in California. The purpose of Prop 65 is not to prohibit certain chemicals or to require substitution of chemicals. Rather, the law mandates warnings when exposures to listed chemicals exceed specified regulatory levels. Identifying exposure levels is not synonymous with determining how much of the chemical is present in the product. This distinction is critical in enforcement actions when assessing whether a company has complied with the Proposition 65 warning requirement.

When deciding whether a product requires a Proposition 65 warning, the central issue is not how much of a chemical is present in a product, but rather how extensive the exposure to the chemical is. Exposure refers to the amount of the chemical that the consumer comes into contact with in the course of using the product, accounting for a number of factors including the nature of the product, the chemical composition, and the manner or frequency with which the product is used. Exposure essentially is the dose of the listed chemical that the consumer receives from the use of a product, expressed in micrograms per day.

In calculating exposure levels, all foreseeable routes of exposure to the listed chemical must be evaluated. There are various avenues through which exposure can occur including eating, touching and breathing in the chemical.

In a Proposition 65 lawsuit, it is defendant’s burden to prove that the alleged exposure is below the warning level for the listed chemical. In contrast, plaintiffs typically rely on calculations of how much of a chemical is present in a certain product to establish a prima facie claim of a Proposition 65 violation. The amount of a chemical in a product can be determined using established testing procedures. As opposed to evaluating exposure levels, evaluating the makeup of a product is usually much simpler and more straightforward – which accounts for how easily a plaintiff can initiate a Proposition 65 claim.

Grimaldi Law Offices has been advising clients for over 20 years on chemical and product law. For knowledgeable advice and in-depth analysis on your Prop 65 compliance obligations, contact Grimaldi Law Offices at (415) 463-5186 or email us at [email protected].

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Ms. Grimaldi maintains a diverse environmental law practice focusing on chemical and product regulation and litigation defense. Her practice areas include Proposition 65, California's Safer Consumer Products Regulations, California's Rigid Plastic Packaging Container Act and the federal Toxic Substances Control Act. Ms. Grimaldi graduated from the University of California Hastings College of the Law magna cum laude and holds a Bachelor of Science Degree in Bacteriology from University of California, Davis. Prior to attending law school, she worked as a research assistant in laboratories at the University of California, San Francisco Cancer Research Institute and at the University of California, San Francisco School of Medicine.