The Office of Environmental Health Hazard Assessment (OEHHA) is proposing to adopt a Proposition 65 No Significant Risk Level (NSRL) for antimony trioxide at 0.13 micrograms per day . Antimony trioxide is a c omponent of flame retardant treatment for polymers; opacifying agent for glasses, ceramics, and enamels; specialty pigments; naturally occurring as valentinite and senarmontite. The public consultation will open until October 12, 2022.