A New Technique for Evaluating Respirator Performance

Evaluation of respirators used for protection against dusts, fumes, and mists significantly more toxic than lead can be conducted utilizing a uranine aerosol with a geometric mean size of 0.20 micron. The uranine aerosol is introduced into an exposure helmet chamber which permits exposure of the subject wearing the respirator to concentrations of below 4 mg/m3. The aerosol is collected continuously outside the respirator and during inhalation in the respirator void with membrane filters. Uranine analysis by fluorescence permits evaluation of respirator penetration as low as 0.05% in a fifteen minute study with an exposure concentration of 3 mg/m3.