B. Johnson et al., EFFICACY OF SELECTED RESPIRATORY PROTECTIVE EQUIPMENT CHALLENGED WITHBACILLUS-SUBTILIS SUBSP NIGER, Applied and environmental microbiology, 60(6), 1994, pp. 2184-2186
The efficacy of powered air-purifying respirators, surgical masks, dus
t/mist respirators, and high-efficiency respirators were tested,vith a
biological aerosol under simulated breathing conditions. Protective a
bility ranged from 67 to 99.95%. The majority of penetration in negati
ve-pressure respirators occurred at the face-mask interface rather tha
n through the filter material.