Wearing an N95 respirator concurrently with a powered air-purifying respirator: effect on protection factor.
Roberge-MR; Vojtko-MR; Roberge-RJ; Vojtko-RJ; Landsittel-DP
Respir Care 2008 Dec; 53(12):1685-1690
OBJECTIVE: To determine if using an N95 filtering face-piece respirator concurrently with a loose-fitting powered air-purifying respirator (PAPR) offers additional protection to the wearer. METHODS: We used a breathing mannequin programmed to deliver minute volumes of 25 L/min and 40 L/min. We measured the baseline protection factor of the PAPR with its motor operational and then deactivated (to simulate mechanical or battery failure). We tested 3 replicates of 3 different N95 models. We glued each N95 to the breathing mannequin and obtained a minimum protection factor of 100 at 25 L/min. We then placed the PAPR on the mannequin and took protection factor measurements with the N95-plus-PAPR combination, at 25 L/min and 40 L/min, with the PAPR operational and then deactivated. RESULTS: The N95 significantly increased the PAPR's protection factor, even with the PAPR deactivated. The effect was multiplicative, not merely additive. CONCLUSIONS: An N95 decreases the concentration of airborne particles inspired by the wearer of a PAPR.
Respirators; Respiratory-protective-equipment; Respiratory-protection; Personal-protection; Personal-protective-equipment; Air-purifying-respirators;
Author Keywords: N95; respirator; powered air-purifying respirator; protection factor
National Personal Protective Technology Laboratory, PO Box 18070, 626 Cochrans Mill Road, Pittsburgh PA 15236
Journal Article; Academic/Scholarly