Effect of exhaled moisture on breathing resistance of N95 filtering facepiece respirators.
Roberge-RJ; Bayer-E; Powell-JB; Coca-A; Roberge-MR; Benson-SM
Ann Occup Hyg 2010 Aug; 54(6):671-677
This study evaluated the effect of exhaled moisture on the breathing resistance of three classes of filtering facepiece respirators (FFR) following 4 h of continuous wear at a breathing volume of 40 L min-1, utilizing an automated breathing and metabolic simulator as a human surrogate. After 4 h, inhalation and exhalation resistance increased by 0.43 and 0.23 mm of H2O pressure, respectively, and average moisture retention in the respirators was 0.26 ml. Under ambient conditions similar to those of the current study, and at similar breathing volumes, it is unlikely that exhaled moisture will add significantly to the breathing resistance of filtering facepiece respirators (FFR) over 4 h of use.
Respirators; Respiratory-protection; Respiratory-protective-equipment; Personal-protective-equipment; Ventilation; Breathing; Filters;
Author Keywords: breathing resistance; filtering facepiece respirators; moisture; N95; respiratory protective equipment
Raymond J. Roberge, National Institute for Occupational Safety and Health, National Personal Protective Technology Laboratory, Pittsburgh, PA 15236, USA
Healthcare and Social Assistance
Annals of Occupational Hygiene