---
type: threshold
id: osmium-tetroxide-as-os
asset: workplace-exposure-limits
title: "Osmium tetroxide (as Os) — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side"
sources:
  - https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
source_quote: "Osmium tetroxide (as Os) | 20816-12-0 | - | 0.002 | - |"
generated: true
harvested: 2026-08-05
stale_after: 2027-08-05
substance: "Osmium tetroxide (as Os)"
cas_number: "20816-12-0"
pel_mgm3: "0.002"
verified: true
---
**Substance:** Osmium tetroxide (as Os)

**CAS No.:** 20816-12-0

**PEL (mg/m³):** 0.002

> Osmium tetroxide (as Os) | 20816-12-0 | - | 0.002 | - |

Source: <https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1>