Workplace protection factor measurements on powered air-purifying respirators at a secondary lead smelter--test protocol.

A study was conducted at a secondary smelter to evaluate the workplace performance of the 3M Model W-344 and Racal Model AH3 powered air-purifying respirators ( PAPR ) equipped with helmets and high efficiency filters. The research protocol developed for obtaining leakage measurements in the field provides for proper respirator fitting, use, wear, maintenance and worker supervision, all of which are problems commonly associated with data acquisition when field testing respirators. The protocol proved to be very workable, even though it required extensive worker and equipment monitoring. Based upon the successful implementation of this protocol, the performance of these PAPRs should be indicative of their best performance under the workplace conditions experienced in this study. This research protocol is proposed as a model for conducting field studies on other types of respirators as well as the basis on which to develop new and improved field test procedures. The results of one such study are presented in a comparison paper.