Abstract
Fit testing is essential to match the N95 (DS2) filtering facepiece respirator with the individual face. However, a properly fitted respirator is relatively difficult to find for women under 40 years old, so structural improvement of the N95 filtering facepiece respirator is required. Almost all N95 filtering facepiece respirators are fixed to the head with only elastic straps. The present study examined if the fitting ratio could be improved for women under 40 years old with adjustable head straps passed around the neck and attached to the respirator near the mouth with a sweat-absorbent 3-D facepiece lip cushion. Twenty subjects wore two types of N95 filtering facepiece respirators, with the adjustable head straps around the neck and attached to the respirator near the mouth with the sweat-absorbent 3-D facepiece lip cushion, and with only elastic straps as a control. Participants were tested with a quantitative fit test using the Mask Fitting Tester Model MT-03TM (Shibata Kagaku Corporation). The permissible range of leakage rate was less than 5.0%. All participants achieved leakage rates of less than 5.0% with normal breathing for the N95 filtering facepiece respirators with the adjustable head straps near the mouth and the sweat-absorbent 3-D facepiece lip cushion. However, five participants had leakage rates over 5.0% with normal breathing using the N95 filtering facepiece respirators with elastic straps only. Three participants had leakage rates of 5.0% or more when bending over with the N95 filtering facepiece respirators with the adjustable head straps near the mouth and the sweat-absorbent 3-D facepiece lip cushion. However, 11 participants had leakage rates over 5.0% when bending over with the N95 filtering facepiece respirators with only rubber elastic straps. This study suggests that the N95 filtering facepiece respirators with the adjustable elastic head straps near the mouth and the sweat-absorbent 3-D facepiece lip cushion provide better fitting for women under 40 years old.
