Prop 65 (California)

Private enforcers filed over 800 Proposition 65 notices of violation in California during 2024 alone, generating more than $30 million in settlements. Unlike most compliance regimes enforced by government agencies, Prop 65 allows private citizens and advocacy groups to sue businesses that fail to provide "clear and reasonable" warnings about exposure to any of 900+ listed chemicals — making it the only major US regulation where enforcement is driven by plaintiff attorneys operating on contingency fees. Any product shipped to California, listed on Amazon, or sold through a retailer with California customers is within scope, regardless of where the manufacturer is headquartered.

Prop 65 compliance decisions are product-specific and substance-specific. For each product, you must determine which listed chemicals may be present, whether consumer exposure exceeds the applicable safe harbor level (if one exists), and what warning language is required under the 2018 updated regulations. REACH and RoHS substance testing data can inform Prop 65 assessments, but the frameworks are not interchangeable — Prop 65 covers naturally occurring substances, process contaminants, and byproducts that neither REACH nor RoHS address.

Sustalium organises Prop 65 compliance at the product-SKU level. Each product record maps its material composition against the current Prop 65 listed chemicals, documents the exposure assessment and safe harbor analysis, and stores the compliant warning text for physical labels and e-commerce listings. When California amends the listed chemicals or updates safe harbor levels, affected product records flag for review. For companies also managing US federal compliance (CPSIA, FSMA, UFLPA), the same underlying product and substance data serves multiple regulatory outputs without re-entry.

For a practical survival guide to UFLPA rebuttable presumption and Prop 65 lawsuits, read our UFLPA and Prop 65 survival guide.