California Adopts Proposition 65 Safe Harbor Levels for Titanium Dioxide

On September 30, 2025, California’s Office of Environmental Health Hazard Assessment (OEHHA) adopted No Significant Risk Levels (NSRLs) for Titanium Dioxide (airborne, unbound particles of respirable size). Effective October 1, 2025, daily exposures at or below these thresholds are considered to pose no significant risk:

• 440 µg/day for unbound, airborne particles with diameters of 10 micrometers (µm) or less

• 44 µg/day for unbound, airborne particles with diameters of 0.8 µm or less

Titanium dioxide is widely used as a white pigment in cosmetic and personal care products. However, only the airborne particle form was listed as a carcinogen under California’s Proposition 65 in 2011. These particles may be found in certain aerosolized or spray-on personal care products, such as sunscreens, hair sprays, and cosmetic powders.

Since its listing, the chemical has been the subject of more than 500 violation notices and many lawsuits, primarily involving cosmetics and personal care manufacturers and retailers. To address industry concerns and reduce litigation risks, the Personal Care Products Council (PCPC) filed a constitutional challenge in 2024, and urged regulators to provide a safe harbor. OEHHA issued a proposal in May 2024, which has now been finalized without changes.

The finalized regulation provides businesses with regulatory certainty. Products with exposure levels below the established NSRLs will not require Proposition 65 warning labels.

Further Reading

• California Updates Proposition 65 Short-Form Warning Regulations

• An Overview of California’s Proposition 65

• U.S. State Legislations for Cosmetics: An In-Depth Look at California