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NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.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

August 30, 1991

Mr. Steven J. Benda
Block-Out Products, Inc.
P.O. Box 782
Cokato, Minnesota 55321

Dear Mr. Benda:

This is in response to your letter of July 1, in which you request an opinion regarding compliance with 29 CFR 1910.147 (Lockout/Tagout) for your circuit breaker blocking and locking devices. You enclosed literature on both your single pole model and multi-pole device, as well as your explanation of the products. We apologize for the delay in responding.

A review of the literature and your explanation of the products revealed the following concern. It was noticed on the multi-pole device that a standard electrical tie wrap is being used as part of a lockout device. This does not meet the intent of 1910.147(c)(5)(ii)(C)(1) which states, "Lockout devices shall be substantial enough to prevent removal without the use of excessive force or unusual techniques, such as with the use of bolt cutters or other metal cutting tools." We do not feel that a standard electrical tie wrap meets this criteria.

Due to constraints placed on OSHA we can neither endorse nor approve products in advance that are to be used in industry, since through improper installation or misuse, the products may not protect employees as intended.

Your interest in workplace safety and health is appreciated.


Patricia K. Clark, Director
Directorate of Compliance Programs