Physiologic and fit factor profiles of N95 and P100 filtering facepiece respirators for use in hot, humid environments

• Published in: American journal of infection control Vol. 44; no. 2; pp. 194 - 198
• Main Authors: Kim, Jung-Hyun, PhD, Wu, Tianzhou, MS, Powell, Jeffrey B., MS, Roberge, Raymond J., MD, MPH
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2016; Mosby-Year Book, Inc; Mosby
• Subjects: Adult; Body Temperature; Carbon Dioxide - metabolism; Environment; Equipment Design; Exercise; Filtering facepiece respirators; Fit factors; Heart Rate - physiology; Hot humid environment; Hot Temperature; Humans; Humidity; Infection Control; Infectious Disease; Life support systems; Male; N95; Occupational Exposure - prevention & control; Oxygen - metabolism; P100; Perceptions; Physiology; Respiratory Protective Devices - standards; Respiratory Rate - physiology; Temperature; Thermophysiologic and subjective responses; Ventilators, Mechanical - standards; Young Adult; Filtering facepiece respirators; N95; P100; Hot humid environment; Fit factors; Thermophysiologic and subjective responses
• ISSN: 0196-6553; 1527-3296
• DOI: 10.1016/j.ajic.2015.08.027

Background To determine if hot, humid ambient conditions impact filtering facepiece respirators' (FFRs') fit, and to evaluate differences in physiologic and subjective responses between N95 FFRs and P100 FFRs. Methods Twelve subjects had physiologic monitoring and subjective perceptions monitored over 1 hour of treadmill exercise (5.6 km/h) in an environmental chamber (35°C, relative humidity 50%) wearing an N95 FFR, P100 FFR, or no respirator. Respirator quantitative fit testing was done before and after exercise. Results There was no significant difference in pass rates for both FFRs on initial fit testing, but subjects who passed were more likely to fail the postexercise test with N95 FFRs ( P  = .01). Wearing FFRs increased the temperature of facial skin covered by the FFR ( P  = .009) and breathing discomfort ( P  = .002). No significant differences were noted in other measured variables (heart rate, respiratory rate, oxygen saturation, transcutaneous carbon dioxide level, rectal temperature, global skin temperature, core temperature, and subjective perceptions) between controls and FFRs and between FFR models. Conclusion After 1 hour of exercise in hot, humid ambient conditions, P100 FFRs retained better fit than N95 FFRs, without additional physiologic or subjective impact. Wearing FFRs under these conditions does not add to the body's thermophysiologic or perceptual burdens.