# Silicon — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side

For Silicon, cas no. is 7440-21-3, verified against its source on 2026-08-05.

- **Substance:** Silicon
- **CAS No.:** 7440-21-3

## What the source says

> Silicon | 7440-21-3 | - | - | - |

## Source

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

Last verified: 2026-08-05. Review by: 2027-08-05.
Part of [US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side](https://referencesource.org/workplace-exposure-limits/).