Antimony trioxide (Cancer)
Antimony trioxide is listed under California Proposition 65 for the Cancer endpoint. Its established safe harbor level is 50 µg/day as a NSRL, determined for exposure primarily via the inhalation route. CAS registry number: 1309-64-4.
Safe Harbor Level
| Field | Value |
|---|---|
| Chemical | Antimony trioxide |
| CAS Number | 1309-64-4 |
| Toxicity Endpoint | Cancer |
| Safe Harbor Basis | NSRL |
| Safe Harbor Level | 50 µg/day |
| Primary Exposure Route | Inhalation |
What this level means
A NSRL is a daily exposure level for Antimony trioxide that — at or below 50 µg/day per day — does not require a Proposition 65 warning because it poses no significant risk for the Cancer endpoint. This is the No Significant Risk Level (NSRL) — the daily intake for the cancer endpoint.
- Level: 50 µg/day per day (NSRL).
- Endpoint: Cancer.
- Route: exposure is assessed primarily through the inhalation route.
- CAS: 1309-64-4.
Businesses that expose consumers to more than the safe harbor level for Antimony trioxide must provide a clear and reasonable Prop 65 warning. Compliance is assessed against the applicable OEHHA safe harbor level above; where no safe harbor level is established, an exposure assessment may be required.
Compliance notes
- Compare the daily exposure to the NSRL of 50 µg/day.
- If exposure exceeds the level, a Prop 65 warning is generally required.
- Confirm the current OEHHA listing and any updates to the level before relying on it — safe harbor levels are amended periodically.
Frequently Asked Questions
What is the Prop 65 safe harbor level for Antimony trioxide?
50 µg/day per day (NSRL).
What is the CAS number for Antimony trioxide?
1309-64-4.
What endpoint is Antimony trioxide listed for?
Cancer.
What is the primary route of exposure for Antimony trioxide?
The inhalation route.
What is the difference between an NSRL and a MADL?
An NSRL (No Significant Risk Level) applies to cancer endpoints; a MADL (Maximum Allowable Dose Level) applies to reproductive and developmental endpoints.