Plastic observation windows for abrasive blasting

August 31, 1983

Mr. Thomas E. Camph
Engineer Manager
[Recipient address omitted]
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.

Sincerely,
Thorne C. Auchter
Assistant Secretary

[Requester letter reproduced on OSHA page; omitted here.]