Products sold in California may be subject to California Proposition 65 Requirements, one of the most recognized chemical disclosure laws in the United States. The regulation requires businesses to evaluate consumer exposure and provide clear and reasonable warnings when exposure exceeds established safe harbor levels. Proposition 65 may apply to a wide range of products sold in California, including cosmetics and personal care products, food products, dietary supplements, medical equipment, toys, furniture, textiles, and other consumer goods.
Understanding these requirements is essential for reducing legal risk, maintaining consumer trust, and ensuring continued market access. This guide outlines the key Proposition 65 compliance requirements, warning obligations, and practical considerations for businesses selling products in California.
What is California Prop 65?
California Proposition 65, formally known as the Safe Drinking Water and Toxic Enforcement Act of 1986, is one of the most recognized chemical disclosure laws in the United States. The regulation is administered by the California Office of Environmental Health Hazard Assessment (OEHHA), which maintains and periodically updates the Proposition 65 list of chemicals based on available scientific evidence.
It requires businesses to provide clear and reasonable warnings before knowingly and intentionally exposing individuals in California to chemicals identified by the State as causing cancer, birth defects, or other reproductive harm.
The presence of a listed chemical does not automatically trigger a warning or prevent a product from being sold in California. Instead, businesses must evaluate whether consumer exposure exceeds the applicable safe harbor level. Consequently, scientifically robust exposure assessments and toxicological risk assessments are fundamental to determining compliance and supporting defensible warning decisions.
Understanding Safe Harbor Levels
A Proposition 65 warning is not determined solely by the presence of a listed chemical. Businesses must evaluate whether consumer exposure exceeds the applicable safe harbor level established by OEHHA.
No Significant Risk Level (NSRL)
The No Significant Risk Level (NSRL) applies to chemicals listed as carcinogens.
Where consumer exposure remains below the applicable NSRL, a Proposition 65 warning is generally not required.
Maximum Allowable Dose Level (MADL)
The Maximum Allowable Dose Level (MADL) applies to chemicals listed for reproductive toxicity, including birth defects and other reproductive harm.
Where consumer exposure remains below the applicable MADL, a Proposition 65 warning is generally not required.
OEHHA has established safe harbor levels for many, but not all, listed chemicals. Where no NSRL or MADL has been established, businesses are responsible for conducting a scientifically defensible exposure and toxicological risk assessment to determine whether a Proposition 65 warning is required.
Key Steps for California Proposition 65 Compliance
Review Ingredients and Raw Materials
Identify whether any ingredients, impurities, contaminants, packaging materials, or other product components contain chemicals listed under Proposition 65.
Supplier documentation and analytical testing may be necessary to verify the presence and concentration of listed substances.
Conduct an Exposure Assessment
Estimate consumer exposure to each listed chemical under the product's intended and reasonably foreseeable conditions of use. This assessment forms the basis for determining whether exposure exceeds the applicable safe harbor level.
Perform a Toxicological Risk Assessment
Compare estimated consumer exposure with the applicable NSRL or MADL. Where no safe harbor level has been established, a scientifically justified toxicological risk assessment is essential to support compliance decisions.
Determine Whether a Warning Is Required
If consumer exposure exceeds the applicable safe harbor level, a clear and reasonable Proposition 65 warning should be provided. Where exposure remains below the applicable threshold, businesses should retain the scientific evidence supporting that conclusion.
Maintain Supporting Documentation
Businesses should maintain scientific and regulatory documentation supporting compliance decisions, including supplier information, analytical testing results, exposure assessments, toxicological evaluations, and warning determinations.
Common California Proposition 65 Compliance Gaps to Avoid
Treating Proposition 65 compliance as a one-time assessment: Compliance should be reviewed periodically, particularly when formulations, suppliers, manufacturing processes, or regulatory requirements change.
Not evaluating impurities and contaminants: Heavy metals, residual solvents, and other unintended contaminants may trigger Proposition 65 obligations even when they are not intentionally added to the formulation.
Using supplier documentation without independent assessment: Supplier declarations are valuable but should be supported, where appropriate, by analytical testing and a product-specific exposure assessment.
Maintaining inadequate compliance documentation: Businesses should retain clear scientific records supporting exposure assessments, warning decisions, analytical testing, and toxicological evaluations to demonstrate compliance if challenged.
Conclusion
California Proposition 65 remains one of the most important chemical disclosure requirements for products sold in California. A proactive compliance strategy supported by ingredient review, exposure assessment, toxicological risk assessment, and robust documentation can help businesses reduce legal risk, strengthen consumer confidence, and support continued access to the California market.
SciQra provides science-driven regulatory and toxicological support for Proposition 65 compliance, from ingredient-level reviews and exposure assessments to warning determinations and compliance documentation.
California Prop 65 Compliance FAQs
What is the Proposition 65 chemical list?
The Proposition 65 list contains chemicals identified by California as causing cancer, birth defects, or other reproductive harm. The list contains more than 1000 substances and includes additives or ingredients in pesticides, common household products, food, drugs, dyes, or solvents.
Does Proposition 65 apply to companies located outside California?
Proposition 65 applies to products sold or distributed in California regardless of where the manufacturer, importer, or brand owner is located.
If a product has already been assessed for Proposition 65 compliance, does it need to be reviewed again?
Proposition 65 compliance is not a one-time exercise. Businesses should periodically reassess products when formulations, raw material suppliers, manufacturing processes, packaging materials, or intended use conditions change. In addition, the Proposition 65 chemical list and associated safe harbor levels are updated periodically by OEHHA. A product that was compliant at one point in time may require reassessment if new chemicals are added to the list or regulatory requirements change.
What does a Proposition 65 warning mean?
A Proposition 65 warning indicates that a listed chemical may be present at an exposure level requiring disclosure under California law. It does not automatically mean that the product is unsafe or prohibited for sale.
If a listed chemical is present only as an impurity, does Proposition 65 still apply?
Potentially, yes. Proposition 65 applies to consumer exposure from listed chemicals regardless of whether they are intentionally added ingredients or present as impurities, contaminants, or by-products. Exposure assessment is therefore a critical part of compliance evaluation.