Standard Interpretations - Table of Contents
• Standard Number: 1926.601(b)(4); 1926.601(b)(4)(i); 1926.601(b)(4)(ii); 1926.602(a)(9)(ii)

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

May 27, 2004

Mr. Richard Holmes
Safety Department Manager
Aggregate Industries
1707 Cole Boulevard, Suite 100
Golden, Colorado 80401

Dear Mr. Holmes:

This is in response to your March 16, 2004, letter to the Occupational Safety and Health Administration's (OSHA) Englewood Area Office regarding the use of a reverse alarm, which is being manufactured in the United Kingdom, on construction sites. The alarm uses "white noise" instead of the more common single-tone alarm.

We have paraphrased your question below:

Question: Does a back-up alarm that uses "white noise" instead of a single tone meet the requirements of 29 CFR 1926.601(b)(4)(i) and 1926.602(a)(9)(ii)?

OSHA is generally precluded from approving or endorsing specific products. The variable working conditions at job sites and possible alteration or misapplication of an otherwise safe