Proposition 65, California: Safe Exposure Levels for Titanium Dioxide

The California Office of Environmental Health Hazard Assessment (OEHHA) has officially approved Negligible Risk Levels (NSRLs) for titanium dioxide in its airborne, unbound, respirable form. This measure, effective October 1, 2025, establishes clear limits that define exposures considered safe under the state's Proposition 65.

Table of contents

• New benchmark values

• Conclusion

Proposition 65, California: Safe Exposure Levels for Titanium Dioxide

New benchmark values

• 440 µg/day for unbound and airborne particles with a diameter equal to or less than 10 µm

• 44 µg/day for unbound and airborne particles with a diameter equal to or less than 0.8 µm

Titanium dioxide is a widely used ingredient as a white pigment in cosmetics, personal care products, and other industrial sectors. However, only its airborne particulate form was included on Proposition 65's list of carcinogens in 2011. This classification particularly affects aerosolized or sprayable products, such as hairsprays, aerosol sunscreens, and cosmetic powders.

Since its inclusion on the list, the substance has been the subject of more than 500 non-compliance notices and numerous lawsuits, primarily against manufacturers and distributors in the cosmetics sector. In response, the Personal Care Products Council (PCPC) filed a constitutional challenge in 2024 requesting the definition of safe levels to reduce legal uncertainty and the litigation burden for companies.

The OEHHA published a proposed regulation in May 2024, which has now been adopted without modification. With this decision, companies now have a clearer regulatory framework: products that keep exposures below the NSRLs will not be required to include Proposition 65 warnings.

Conclusion

This update represents a significant step forward for the cosmetics and personal care industry, by offering scientific and consistent criteria that balance consumer protection with the legal certainty of manufacturers.