Proposition 65: No Significant Risk Levels for Titanium Dioxide (airborne, unbound particles of respirable size)

The Office of Environmental Health Hazard Assessment (OEHHA) has adopted No Significant Risk Levels (NSRL) for titanium dioxide (airborne, unbound particles of respirable size)of 440 micrograms per day for airborne, unbound titanium dioxide particles with diameters of 10 micrometers or less, and 44 micrograms per day for airborne, unbound titanium dioxide particles with diameters of 0.8 micrometers or less. (Adopted in Title 27, California Code of Regulations, section 25705(c)(2).)

Final Approval/OAL Action

The Office of Administrative Law (OAL) approved the rulemaking and filed it with the Secretary of State on June 18, 2025. The effective date for the regulation is October 1, 2025.

Final Regulatory Text 

Final Statement of Reasons

Proposed Rulemaking

On May 10, 2024, OEHHA issued a Notice of Proposed Rulemaking, proposing to adopt NSRL levels for titanium dioxide (airborne, unbound particles of respirable size) by amending Title 27, California Code of Regulations, section 25705(c)(2). The public comment period for this proposed rulemaking was open May 10 to July 1, 2024.

Notice of Proposed Rulemaking

Initial Statement of Reasons

Proposed Regulatory Text

Link to Public Comments

Link to Public Comments

Chemical Reference