Document 7wQaBvZLDQ2yz03aoKkOY5rV

(dbp doreli bevis associates, inc. 14640 flint Le* Stood. Suite D Cnantiily. Virglnio 22021 (700) 076-0000 T1-- Oune 17, 1987 Mr. L.J. Cunningham Acting Chief Radiation Protection Branch, NRR U.S. Nuclear Regulatory Commission Washington, DC 20335 Dear Mr. Cunningham: This is to inquire as to the official NRC enforcement position regarding the acceptability of the use of a relatively new device, the TSI Portacount Respirator Fit Tester, as a quantitative respirator fit test instrument. As you may be aware, this new instrument - manufactured by T51 Incorporated, 500 Cardigan Road, P.O, Box 64394, St. Paul, MN 55164? (612) 483-0900 - uses the ambient air particulate matter as the ^challenge" for its comparative measurement of concentrations outside and inside a respirator facepiece to determine a fit factor. Since this concept or type of instrument is not discussed in any existing regulation or guidance, some question has been raised over its ability to meet the require ments of quantitative respirator fit testing and the NRC's acceptance of its use. Please advise on this matter as soon as possible. Sincerely, Bohn P. Hale Director, Respirator Programs SPH/afb VVV 000006676