The effect of storage conditions on the respirator performance

• Main Authors: Hong-Chin Yu, 游鴻欽
• Other Authors: 鄭曼婷
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/61658164412733814873

碩士 === 國立中興大學 === 環境工程學系所 === 97 === Abstract N95 respirators play an important role in epidemic diseases protection. Therefore, many countries have included N95 respirators as epidemic prevention materials, so have domestic public health offices. As a result, how long N95 respirators could be preserved and whether the temperature and humidity in the storage environment would affect the respirator''s performance, have become a concerning issue by medical organizations. Due to these concerns, this research is the first domestic study that used N95 respirators stored for five years as research subject. This research studied effect of the temperature and humidity on the filtration efficiency and the fitness of the respirator. To test the respirators filtration efficiency, an automatic filter tester was used to test the penetration and pressure drop of six different models of A, B, C, D, E, and F of five-year respirators and three models of A, B, and C of new respirators. In addition, the change of filtration efficiency of the new respirators treated over 24 hours under 90℃, 25℃, and -10℃ was also tested. This test was conducted by automizing a 2% sodium chloride solution by using an atomizer operated under 30 psi to generate the droplets. After drying the droplets, the count median diameter of the particles is 0.07μm. The filtration efficiency of a respirator is tested with the gas flow rate at 85L/min. To test the respirators fitness, we used quantitative fit test system to measure the fitness of the three models of new respirators worn by real person. The testing method is to use a differential mobility analyzer to select the particles of 40nm in diameter. N95 respirators are capable of filtering out almost all 40nm particles, therefore, the 40 nm particles measured within the respirator would be considered due to the leakage caused by poor fitness. Base on the experiment of results, it was found that the respirators filtration efficiency of model C and E of five year respirators are lower than 95%, these inefficient respirators accounted for 10% and 5% of model C and E respirators, respectively. High temperature at 90℃ significantly decreased the filtration efficiency and pressure drop of model C respirators. As to the respirator fit test, in average over 50% of testees failed. This implies the tested respirators did not fit the testees. Therefore it is necessary to test the fitness of the respirators of different sizes when the medical personnel first time use an N95 respirator.