This study aim to evaluate the most frequently used non-powered tight-fitting air-purifying respirators with canister and N95 facemasks. The N95 facemask which the facepiece itself is the purifying element is also used by medical personnel. Research results have indicated the respirators are available and in use in only 20-30% of the work phases evaluated as needing them. Failure to use a respirator is influenced by the physiological burden caused by such as additional respiratory resistance and dead space, by psychological factors such as subjective discomforts, and by thermo stress caused by the environment and respirator itself. There were lots of researches addressing the physiological effects of wearing respirators with canister. Only little research focused on N95 facemask which is associated with smaller breathing resistance when compared with respirator with canister. However, the N95 facemask is still need to be assessed because it may become wet and the breathing resistance may increase after prolonged use. The subjective discomfort associated with respirator wearing has not been studied systematically, but it is widely agreed that wearer discomfort represents a crucial issue to interfere with the use of respirators. The climate of Taiwan is humid and hot in some seasons. Working with respirators under non-temperate environments may induce additional work stress and should be investigated. Therefore the present study intend to assess the physiological loads and subjective discomforts and their effects on the wearing behaviour for non-powered tight-fitting air-purifying respirator with canister and N95 facemask under prolonged use and thermo condition. The identified factors will facilitate the appropriate use of these two types of respirators.
