Ezel / Labor Guidance / US
Back to Federal guidance

Muriatic acid and process safety management listing

Summary A chemical company asked if 32 percent muriatic acid was covered by OSHA's process safety management rule. OSHA said Appendix A listed hydrogen chloride and anhydrous hydrochloric acid, but did not list hydrochloric acid dissolved in water. It therefore said the muriatic acid solution was not subject to that listing.
Document
Federal opinion letter
Agency
Occupational Safety and Health Administration (OSHA)
Document number
1992-06-24-2
Date issued
June 24, 1992
Status
Active
Status last verified October 9, 2026
Topics
Workplace Safety OSHA 1910 Process Safety Management Hazardous Chemicals
Source
View the official document

Apply this to your situation

This page explains the general guidance. Ask about your specific situation and see what current federal labor law says, with citations.

About this page: The full text below is the official document from Occupational Safety and Health Administration (OSHA). Ezel adds the plain-English summary and tracks the document's status. The official source linked on this page is authoritative for any reliance.

June 24, 1992

Mr. Frank R. Samartinov
Process Safety Engineer
Hoechst Celanese
[Recipient address omitted]
Dear Mr. Samartino:

This is in response to your May 11 letter, requesting written confirmation that the Final Rule on Process Safety Management (PSM) of Highly Hazardous Chemicals published in Volume 57, Number 35 of the Federal Register on Monday, February 24, 1992 does not apply to muriatic (32% HCL) acid.

The chemical names: hydrogen chloride (HCL) and anhydrous hydrochloric acid are included in the highly hazardous chemicals listing in Appendix A of the PSM standard. Anhydrous (without water) hydrochloric acid is hydrogen chloride. Both hydrogen chloride and anhydrous hydrochloric acid are identified by the same Chemical Abstract Service (CAS) Number 7647-01-0, as denoted in Appendix A. Hydrochloric acid (muriatic acid), that is, a solution of hydrogen chloride gas in water, is not listed in Appendix A and therefore, is not considered to be a highly hazardous chemical subject to the PSM standard.

Thank you for your interest in occupational safety and health. If we may be of further assistance, please contact us.

Sincerely,

Patricia K. Clark, Director
Directorate of Compliance Programs

Related guidance

Permanently labeled locks for electrical lockout Opinion Letter · August 17, 2026 Helmet selection for lateral head-impact hazards Opinion Letter · August 17, 2026 Asbestos precautions when restoring drywall after flood damage Opinion Letter · May 7, 2026 Enforcement policy for recording and reporting COVID-19 cases Guidance · March 31, 2026

What does federal law require in your situation?

Ezel checks current federal labor law against your facts and answers with citations.

Opens in Ezel Pro.

  • Checks the law as it stands today, not only this page
  • Cites every source it relies on, so you can verify it
  • Chat, drafting and research in one workspace