# Perlite — workplace exposure limit

For Perlite, niosh rel, as stated is TWA 10 mg/m3 (total) TWA 5 mg/m3 (resp); cas no. is 93763-70-3, verified against its source on 2026-09-08.

- **Substance:** Perlite _(verified: appears in its own passage below)_
- **CAS No.:** 93763-70-3 _(verified: appears in its own passage below)_
- **NIOSH REL, as stated:** TWA 10 mg/m3 (total) TWA 5 mg/m3 (resp) _(verified: appears in the quote below)_

## What the source says

> NIOSH REL TWA 10 mg/m3 (total) TWA 5 mg/m3 (resp)

## Where each value comes from

This source states these in separate places, so each value is shown with the passage that states it.

### Substance

> CDC - NIOSH Pocket Guide to Chemical Hazards - Perlite

### CAS No.

> CAS No. 93763-70-3

## Source

- https://www.cdc.gov/niosh/npg/npgd0491.html

Last verified: 2026-09-08. Review by: 2027-09-08.
Part of [US workplace chemical exposure limits: federal OSHA, Cal/OSHA and NIOSH, side by side](https://referencesource.org/workplace-exposure-limits/).