January 10, 1994

Mr. David S. Pearson
Atlantic Environmental Incorporated
2 E. Blackwell Street
Dover, New Jersey 07801

Dear Mr. Pearson:

Thank you for your letter of December 13, 1993 concerning respirator selection requirements prescribed in the Occupational Safety and Health Administration (OSHA) standard on benzene exposure, 29 CFR 1910.1028. You requested confirmation of answers of two questions for which Mr. Ching-tsen Bien of my staff had responded during your telephone conversation with him.

The answers to your questions follow:

1. Is a hood type powered air-purifying respirator, which meets the performance criteria prescribed in the footnote of Table 1 of the benzene standard, acceptable for protection against up to 100 ppm concentrations of benzene?

Yes, if during intended applications a positive pressure is maintained inside the respirator inlet covering.

2. Is a continuous flow supplied air hood acceptable for protection against up to 1,000 ppm concentrations of benzene?

Yes, if during intended applications a positive pressure is maintained inside the respirator inlet covering.

Please contact us again if you need further assistance.

Sincerely,



Patricia K. Clark
Director
Directorate of Technical Support