# Uranium (natural), insoluble compounds, as U — workplace exposure limit

For Uranium (natural), insoluble compounds, as U, pel (mg/m³) is 0.2; stel (mg/m³) is 0.6, verified against its source on 2026-09-29.

- **Substance:** Uranium (natural), insoluble compounds, as U _(verified: appears in the quote below)_
- **PEL (mg/m³):** 0.2 _(verified: appears in the quote below)_
- **STEL (mg/m³):** 0.6 _(verified: appears in the quote below)_

## What the source says

> Uranium (natural), insoluble compounds, as U | -- | 0.2 | | -- | 0.6

## Source

- https://www.dir.ca.gov/title8/5155.html

Last verified: 2026-09-29. Review by: 2027-09-29.
Part of [US workplace chemical exposure limits: federal OSHA, Cal/OSHA and NIOSH, side by side](https://referencesource.org/workplace-exposure-limits/).