California’s Proposition 65 (or “Prop 65” as it is often referred to) requires companies doing business in California to notify consumers of potentially hazardous chemicals present in their products and packaging. For products that may cause significant exposure to listed compounds, the warning label must state that the product “contains chemicals known by the State of California to cause cancer or reproductive harm.” A proposition 65 label can cause consumers to seek alternative products, ultimately hurting sales.

Demonstrating compliance can be a daunting task for manufacturers and retailers selling their products in California. With almost 900 listed chemicals of concern in the Proposition 65 List of Chemicals, frequent changes to the list, and varying thresholds by product and substance, manufacturers need expertise and precision testing to meet Prop 65 requirements and avoid potential fees and litigation.

Manufacturers and retailers that sell in California, need to perform due diligence to determine if products require Proposition 65 labeling. UL’s customers rely on our toxicology and chemical testing expertise to help assess their risk of having chemicals of concern in their products.

  • Product Line and Supply Chain Assessment – UL will review raw material and component supply chains to determine the likelihood that chemicals of concern may be present. We make recommendations on supplier requirements and test programs to help monitor the presence of listed chemicals and mitigate risk in the supply chain.
  • Chemical Emissions Testing – UL uses dynamic environmental chamber technology to detect and measure the chemicals that a product emits, providing measurable, verifiable data – the first step in meeting Prop 65 requirements.
  • Chemical Testing – Around the world to conduct testing for the chemicals listed within the Prop 65 regulation in products and raw materials.
  • Exposure Assessments – For products that include one or more listed compounds, UL’s technical experts can perform an exposure assessment. An exposure assessment evaluates how much of a substance a person inhales, ingests or absorbs through the skin. Our product toxicology experts work with manufacturers to determine reasonable usage of their products to assess if exposure above the save harbor level is likely.
  • Safe Harbor Level Development – For chemicals that do not have a safe harbor level established by the state of California, UL’s toxicology experts can develop a reference level for use in the exposure assessment.

Do your products require a label under the Prop 65 regulation? Safe products are paramount to long-term business success, a strong brand and happy, loyal consumers. Protect your brand, differentiate your products, mitigate risk, and demonstrate your commitment to the safety and health of your consumers with UL’s Prop 65 Compliance solutions.



  • Reduce Risk
  • Reach Health-Conscious Buyers
  • Sell Safer Products

By working with UL to conduct Prop 65 testing, manufacturers help ensure that they are offering a safer, more sustainable product. They also benefit from testing and evaluation by a third party trusted by green and health-conscious buyers. UL has the expertise and capabilities to offer complete assessment, evaluation, testing and consulting services, allowing manufacturers the convenience of working with a single partner for all their needs. To learn more about California Proposition 65 and UL’s Proposition 65 Solutions, send an email to or call the phone numbers below. We look forward to helping you understand Proposition 65 testing requirements and the Prop 65 testing labs that meet your needs.

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For more information about UL’s Prop 65 Solutions, contact us at:



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