# Aluminum — workplace exposure limit For Aluminum, niosh rel, as stated is TWA 10 mg/m3 (total) TWA 5 mg/m3 (resp); cas no. is 7429-90-5, verified against its source on 2026-09-08. - **Substance:** Aluminum _(verified: appears in its own passage below)_ - **CAS No.:** 7429-90-5 _(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 - Aluminum ### CAS No. > CAS No. 7429-90-5 ## What osha.gov says > Aluminum, metal (as Al) | 7429-90-5 | - | - | - | Source: https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1 ## Source - https://www.cdc.gov/niosh/npg/npgd0022.html - https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1 Last verified: 2026-09-08. Review by: 2027-08-05. Part of [US workplace chemical exposure limits: federal OSHA, Cal/OSHA and NIOSH, side by side](https://referencesource.org/workplace-exposure-limits/).