Although measuring the workplace protection factor (WPF) is important to verify the performance of particulate respirators in a real work environment, there are no reports of such measurements in Japan. The aim of this study was to measure the WPF of a replaceable particulate respirator (RPR) and a powered air-purifying respirator (PAPR). Eight participants were subjected to three conditions: wearing a RPR correctly (C-RPR), wearing a RPR as usual (but incorrectly) (U-RPR), and wearing a PAPR in the same way as U-RPR (PAPR). Subjects performed dust-generating tasks for 15 min, during which the WPF was measured. The WPF was calculated by dividing the concentration of particles outside the particulate respirator (Co) by that inside the particulate respirator (Ci). A fit testing instrument was used to measure the number of particles. Ci was measured by inserting the test guide into the face piece, and Co was measured by fixing the test guide near the breathing area of the subjects. The WPF geometric mean values (standard deviations) for C-RPR, U-RPR, and PAPR were 17.7 (2.59), 27.0 (3.86), and 117.3 (5.25), respectively. It is important to generate knowledge about the performance of particulate respirators to prevent occupational respiratory diseases.
