Contributing factors to sandblasters' silicosis: inadequate respiratory protection equipment and standards.

National concordance standards for respiratory protection during abrasive blasting have existed for more than 50 years; however, these standards have not kept pace with advances in blast equipment, have not provided realistic estimates of expected protection in the workplace, and have been misused by manufacturers and distributors of respiratory protective equipment who have assured, through sales literature, that the equipment is acceptable for conditions under which they have never been tested. This situation has contributed to exposure of sandblasters to hazardous levels of respirable free silica, and is reviewed here to prevent a continuation of the incompatibility of these and other standards for respiratory protection with the actual exposures to various noxious inhalants in the workplace.