Abstract
Dust measurements should give results related closely to the health hazard, be simple, reproducible, and inexpensive. Measurement of total airborne mass concentration or, preferably, respirable mass concentration is simpler, cheaper and gives more reproducible results than the impinger. Comparative sampling indicates that a respirable dust limit of 10/(% Respirable Quartz + 2) mg/m3 would be equivalent to the present impinger TLV. A total dust limit proposed is: 30/(% Quartz + 2) mg/m3. Either mass limit permits personal sampling techniques to be used. Quartz analyses are made on the respirable fraction for the respirable limit, and on total dust for the total dust limit. Until safety of present quartz limits is demonstrated, the limits should be used conservatively.
