The interpretation of the OSHA standards 1910.134 and 1910.156 which address the requirements for workers who are actively conducting operations in atmospheres that are immediately dangerous to life and health.

OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

November 1, 1995

Mr. Thomas N. Cooper
Certified Safety Professional
Fire Safety Specialist
Purdue University
1666 L.J. Freehafer
Hall of Administrative Services
West Lafayette, Indiana 47907-1666

Dear Mr. Cooper:

Respiratory protection and emergency escape requirements for IDLH atmospheres.

OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

January 13, 2003

Mr. John Randall
Water Pollution Control Facilities
7525 Bertram Road South East
Cedar Rapids, Iowa 52403-7111

Dear Mr. Randall:

Permit-Required Confined Space Entry Requirements For IDLH and Non-IDLH Spaces

OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

July 17, 2014

Mr. William Verhayden
Precision Industrial Maintenance, Inc.
1710 Erie Boulevard
Schenectady, New York 12308

Dear Mr. Verhayden:

Thank you for your letter to the Occupational Safety and Health Administration (OSHA) for a clarification of OSHA’s Permit-Required Confined Spaces standard, 29 CFR §1910.146 (hereinafter, "the standard"). This constitutes OSHA's interpretation only of the requirements discussed and may not be applicable to any question not delineated within your original correspondence.