Archive Notice - OSHA Archive

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

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

February 25, 1977

Mr. Henry C. Gullo
State of New York
Executive Department
Office of General Services
Tower Building Empire
State Plaza Albany, New York 12242

Dear Mr. Gullo:

This is in response to your letter of November 24, 1976, addressed to Mr. Alfred Barden, our New York Regional Administrator, and subsequently forwarded to the Occupational Safety and Health Administration (OSHA) National Office. The letter requested information concerning OSHA standards on exit requirements in steam tunnels.

A steam tunnel is considered a structure. When an employee's worksite is in a steam tunnel, the employer is required to comply with the applicable standards of 29 CFR 1910.36, Means of Egress; General Requirements.

Section 1910.36(b)(1) defines the fundamental requirements stating, "Every building or structure, new or old, designed for human occupancy shall be provided with exits sufficient to permit prompt escape of occupants in case of fire or other emergency." For example, a man-tunnel parallel with the steam tunnel having connections every 50 feet as exits from the steam tunnel would be satisfactory. If this example is not practical, then there are requirements by the other section of the same standard which states, "The design of exits and other safeguards shall be such the reliance for safety to life in case of fire or other emergency will not depend solely on any single safeguard; additional safeguards shall be provided for life safety in case any single safeguard is ineffective due to some human or mechanical failure."

Regarding other safeguards and precautions on steam tunnels, we suggest you follow standard engineering practices, Code for Safety to Life from Fire in Buildings and Structures, NFPA 101, and other national concensus standards.

If I may be of any further assistance please feel free to contact me.


Richard P. Wilson
Deputy Director,
Federal Compliance and State Programs