• Standard Number:

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 http://www.osha.gov.

July 20, 1983

Mr. F. K. Parmely
Corporate Safety and
Health Department
Brown and Root, Incorporation
P.O. Box 3
Houston, Texas 77801

Dear Mr. Parmely:

This is in response to your letter of July 7, 1983, requesting a clarification of 29 CFR 1910.23(a)(9) as it applies to fixed ladders and platforms. This also confirms your telephone conversation with a member of my staff, Mr. Simms. The answer to your specific questions follow.

1. 29 CFR 1910.23(a)(9) does apply to the distance between a vessel wall and a platform toeboard; however, the condition detailed in your letter appears to be a de minimis violation of the standard. I am enclosing a portion of OSHA Instruction CPL 2.45A, which defines a de minimis violation. Citations are not issued for de minimis violations, penalties are not proposed, and abatement of the violation is not required of the employer.

2. A vertical barrier, i.e., toeboard, terminates the walking/working surface of the platform, as illustrated on your Diagram D. This appears to be a de minimis violation of 29 CFR 1910.23(a)(9).

3. 29 CFR 1910.23(b)(5) and 29 CFR 1910.27(d)(2)(ii) are both applicable for platforms used with fixed ladder.

4. 29 CFR 1910.23(b)(5) addresses the condition where a wall normally provides the equivalent protection of a toeboard but, because of a wall hole at the toeboard elevation, a toeboard or an enclosing screen must be used to cover the wall hole, when the far side of the hole is more than 5 feet above the next lower level.

I hope this information is helpful to you. If I may be of further assistance, please feel free to contact me.


John K. Barto, Chief,
Division of Occupational
Safety Programming



M/R: This response was coordinated with the directorate of Safety Standards.

Mr. Don Shay
Occupational Safety and
Health Administration
Office of Administration
Washington, D.C. 20210

Dear Mr. Shay:

Request occupational safety and health [29 CFR 1910.23(a)(9)] standard clarification as to application of fixed ladders and platform in the attached Diagram A-D, "illustration only".

1. Does 29 CFR 1910.23(a)(9), April, 1981, quote, "every floor hole into which persons cannot accidentally walk (on account of fixed machinery, equipment, or walls) shall be protected by a cover that leaves no openings more than one (1) inch wide. The cover shall be securely held in place to prevent tolls or materials from falling through," unquote, apply to the distance between (as illustrated in attached Diagram B, C, and D) vessel wall and platform toeboard?

2. Does the installation of a vertical barrier i.e. toeboard terminate the walking/working surface of a floor or roof, as attached in Diagram D?

3. Does specific 29 CFR 1910 standards over ride the requirement of 20 CFR 1910.23(a)(9) such as 29 CFR 1910.27(d)(2)(ii) for fixed ladders?

4. Request standard clarification for 29 CFR 1910.23(b)(5) by diagram, photo, illustration, etc... if possible.

Your prompt response in writing would be appreciated. If you have any question pertaining to this request, please contact me at (713) 676-7824.


F. K. Parmely
Corporate Safety & Health Dept.