Standard Interpretations - Table of Contents
• Standard Number: 1926.500(b) ; 1926.501(b)(1); 1926.501(b)(4)(i); 1926.501(b)(4)(ii); 1926.502(b)

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

September 30, 2004

Mr. Bob Kersten
Received via e-correspondence

Dear Mr. Kersten:

In your e-correspondence submitted June 28, 2004, and in subsequent telephone conversations with our staff, you asked about OSHA construction standards that pertain to a depression in a finished concrete ground floor.

We have paraphrased your question as follows:

Question: Scenario: There is a depression in a finished concrete ground floor. The ground floor measures approximately 200 feet by 350 feet. The depression is 7 feet wide, 70 feet long, and 33 inches deep. It has concrete walls and a concrete floor. Are guardrails required under 29 CFR Part 1926 Subpart M around this depression?

The answer to your question depends on whether, under the standard, the depression constitutes an unprotected side/edge or a hole.

Section 1926.501(b)(1)(unprotected sides and edges) states: