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 12, 1996

Mr. James R. Rhudy
Corporate Safety Manager
Chicago Bridge & Iron Company
1501 North Division Street
Plainfield, Illinois 60544-8929

Dear Mr. Rhudy:

This is in response to your letter dated June 27, 1996 in which you requested standard interpretations on the following: 29 CFR 1910.23(a)(9) and 1910.24(e).

In your letter you asked, "Is there an interpretation that permits a 2 inch opening, or can we use a toeboard to protect a floor hole where no one can accidentally walk?"

29 CFR 1910.27(b)(4) of the proposed standard (a copy is attached for your information) states: "A floor hole less than one foot (30.5 cm) in its least dimension (the shortest distance from the edge of the work surface or toeboard to the object going through the work surface) provided for passage of machinery, piping, or other equipment that may expand, contract, vibrate and/or move in a similar manner, need only be guarded by a toeboard or equivalent means to prevent the feet of employees from entering the hole or tools from falling through the opening and onto employees below."

In reference to your second question in which you asked, "What is the permissible tolerance or variation in riser height? Can we have a step that is 9 inches vertically from another step and then have the next step at 8-7/8 inches? The construction standard 1926.1052(a)(3), permits a 1/4 inch variation in riser height or tread depth. What is permitted in General Industry?"

The De Minimis Violation Section of OSHA's Instruction CPL 2.103 states that minor deviations from standards that have no direct or immediate relationship to employee safety or health are acceptable.

If you have any further questions about this response, please contact Ms. Patricia Biles of my staff at 202-219-8031, ext.111. We thank you for your interest in safety and health.

Sincerely,



John B. Miles, Jr., Director
Directorate of Compliance Programs




June 27, 1996

Mr. John Miles, Director
Compliance Program
U.S. Department of Labor/OSHA
Room N-3468
200 Constitution Avenue, N.W.
Washington, DC 20210

Re: Request for Interpretation 1910.23(a)(9) and 1910.24(e)

Dear Mr. Miles:

Pursuant to a discussion with Don Kallstrom, we would appreciate an official interpretation on the following:

1910.23(a)(9)

We have a cutout in floor grating for a 13 inch diameter pipe. Attached to the pipe near grating level is a victaulic coupling that joins the pipes together. The diameter at the two bolting location of the victaulic coupling is 15-3/8 inches. There is a 3-1/2 inch space between the pipe and grating, except in the bolting locations. A cover that leaves so more than 1 inch wide at the pipe is not practical. It would impede access to the bolts and be a difficult fit at best.

Isn't there an interpretation that permits a 2 inch opening in this application? Or, can we use a toe board to protect this floor hole where no one can accidentally walk? This would keep tools, equipment, etc. from being inadvertently knocked into the hole and would permit ready access to the bolts for the victaulic coupling.

1910.24(e)

We would appreciate a definition of uniform. For example, if we have a stairway at 45 degrees, the rise is 8-3/4 inches. What is the permissible tolerance or variation in riser height? Can we have a step that is 9 inches vertically from another step and then have the next step at 8-7/8 inches? The construction standard 1926.1052(a)(3), permits a 1/4 inch variation in riser height or tread depth. What is permitted in General Industry?

We would appreciate a prompt response. My direct phone number is (815) 439-6689; our department's fax number is (815) 439-6677.

Yours truly,



James R. Rhudy
Corporate Safety Manager