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.

October 15, 1990

Mr. Bill Betzner
Applications Manager Notifier
12 Clintonville Road
Northford, Connecticut 06472-1001

Dear Mr. Betzner:

This is in response to your inquiry of June 11, to Mr. Joseph Bode of my staff. You requested that the Occupational Safety and Health Administration (OSHA) confirm your position that control systems used for emergency evacuation are required to be listed by Underwriter's Laboratories. Please accept my apology for the delay in response.

OSHA's electrical standards for general industry are contained in 29 CFR 1910.301 through .339 (Subpart S). Paragraph (a) of 1910.303 states that conductors and equipment required or permitted by this subpart shall be acceptable (i.e., all conductors and equipment covered by Subpart S) only if approved. The definitions of "approved" and "acceptable" indicate that acceptance by a nationally recognized testing laboratory, such as those listed in the enclosure, is necessary to meet the requirement in 1910.303(a). Since Subpart S generally applies to all electrical equipment and conductors that are installed as part of the premises wiring, permanently installed communications equipment would also need such approval.

If we can be of further assistance, please do not hesitate to contact us.


Patricia K. Clark
Director Designate
Directorate of Compliance Programs