NIOSHTIC-2 Publications Search

Are exhalation valves on N95 filtering facepiece respirators beneficial at low-moderate work rates: an overview.

Roberge RJ

J Occup Environ Hyg 2012 Nov; 9(11):617-623

https://doi.org/10.1080/15459624.2012.715066

20041517

Exhalation valves (EVs) are touted as useful in dissipating humidity, heat, and carbon dioxide from the dead space of N95 filtering facepiece respirators and decreasing exhalation resistance, thereby making the respirator more comfortable and less physiologically demanding. Despite decades of use, there is limited research on the psychophysiological impact of EVs on the wearer at the current, low-moderate work rates of many workers. The available literature indicates that past and current EVs on the market decrease exhalation resistance to a variable degree and may improve dead space heat dissipation and, consequently, the temperature of the skin covered by the respirator. EVs have little substantial effect on dead space humidity, respiratory rate, heart rate, core temperature, speech intelligibility, or dead space oxygen and carbon dioxide levels at the aforementioned work rates. The studies also indicate that EVs may impact comfort and tolerance when N95 filtering facepiece respirators are worn for extended periods or at high work rates. Because comfort and tolerance impact respirator use compliance and, by extension, protection, more research into the psychophysiological impact of EVs on wearers and the development of new EVs tailored for low-moderate work rates are warranted.

Performance-capability; Personal-protective-equipment; Respirators; Respiratory-equipment; Respiratory-protective-equipment; Air-purifying-respirators; Face-masks; Respiration; Psychological-reactions; Physiological-response; Work-performance; Work-capacity; Heat; Humidity; Author Keywords: N95 filtering facepiece respirators; exhalation valves; psychophysiological impact

Raymond J. Roberge, National Institute for Occupational Safety and Health, National Personal Protective Technology Laboratory, 626 Cochrans Mill Road, Pittsburgh, PA 15236, USA

JOEHA2

124-38-9

20121101

Journal Article

dtn0@cdc.gov

2013

B09262012

11

1545-9624

NPPTL

Wholesale and Retail Trade

Journal of Occupational and Environmental Hygiene

PA