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.

August 31, 1983

Mr. Thomas E. Camph
Engineer Manager
P.O. Box 7680
San Francisco, California 94120

Dear Mr. Camph:

This is in response to your letter of August 11, 1983, requesting a clarification of a safety requirement in Subpart G of our General Industry Standards.

29 CFR 1910.94(a)(3)(i)(d) does require safety glass protected by screening to be used in observation windows, where hard deep-cutting abrasives are used. However, employers using a plastic material with equivalent or greater strength and the same optical clarity of safety glass, protected by screening and properly maintained, would meet the intent of this standard.

Employers using the plastic material in lieu of safety glass could be in technical violation of 29 CFR 1910.94(a)(3)(i)(d). This technical departure from the standard would be noted as a de minimis violations, penalties are not proposed, and abatement of the violation is not required of the employer.

I hope I have answered your concerns. Please feel free to contact me if you have any questions or need additional information.


Thorne C. Auchter
Assistant Secretary

August 11, 1983

Mr. Thorne G. Auchter
Assistant Secretary
Occupational Safety and Health
U.S. Department of Labor
Washington, D.C. 20210

Dear Mr. Auchter:

By way of this letter I am hereby petitioning for the promulgation, modification, or revocation of an OSHA standard. The standard I refer to is Section 1910.94 (a) (3) (i) (d) of the Occupational Safety and Health Standards which states:

"Safety glass protected by screening shall be used in observation windows, where hard deep-cutting abrasives are used."

A question arises regarding the language in this statement, namely, does the reference to "safety glass" necessarily rule out other materials? The plastics industry has developed several materials that are more abrasion resistant and shatterproof than glass while maintaining the same optical clarity. We would like to investigate the use of these materials for blast cabinet windows.

Please let me know the proper interpretation of this Section, and, particularly, if there are any restrictions to exploring alternate window materials. If you have any questions or need more information, please feel free to contact me at any time.

Best regards,

Thomas E. Camph
Engineering Manager