On May 10, 2024, OEHHA issued a notice of proposed rulemaking to adopt a Proposition 65 No Significant Risk Level (NSRL) for titanium dioxide (airborne, unbound particles of respirable size).  This chemical was listed as a Prop 65 chemical known to cause cancer in September 2011. As recognized in OEHHA’s Initial Statement of Reasons for the proposed NSRL, potential plaintiffs have sent an increasing number of 60-Day Notices for exposures to this chemical in recent years, and a First Amendment challenge to warnings for such exposures from cosmetic and personal care products is pending in federal court (The Personal Care Products Council v. Bonta, E.D. Cal. No. 2:23-cv-01006-TLN-JDP).  

OEHHA’s proposed NSRL for titanium dioxide (airborne, unbound particles of respirable size) requires both that: 

1. The exposure to particles with diameters of 0.8 µm or less is below 44 µg/day; and 
2. The exposure to particles with diameters of 10 µm or less is below 440 µg/day.

The deadline for public comments on this proposed rulemaking is June 24, 2024. More information on the rulemaking can be found here.