# bis-Chloromethyl ether — workplace exposure limit For bis-Chloromethyl ether, niosh rel, as stated is Ca See Appendix A; cas no. is 542-88-1, verified against its source on 2026-09-08. - **Substance:** bis-Chloromethyl ether _(verified: appears in its own passage below)_ - **CAS No.:** 542-88-1 _(verified: appears in its own passage below)_ - **NIOSH REL, as stated:** Ca See Appendix A _(verified: appears in the quote below)_ ## What the source says > NIOSH REL Ca See Appendix A ## 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 - bis-Chloromethyl ether ### CAS No. > CAS No. 542-88-1 ## Source - https://www.cdc.gov/niosh/npg/npgd0128.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/).