NIOSH, NPPTL, Pittsburgh, Pennsylvania.
NIOSH/NPPTL, Morgantown, West Virginia.
J Occup Environ Hyg. 2021 Jul;18(7):305-313. doi: 10.1080/15459624.2021.1919685. Epub 2021 May 26.
Recently, total inward leakage (TIL) for filtering facepiece and elastomeric half-mask respirators (EHRs) was measured according to the International Organization for Standardization (ISO) test method standard 16900-1:2014 that showed larger TIL for corn oil aerosol than for NaCl aerosol. Comparison of TIL measured for different aerosols for higher protection level respirators is lacking. The objective of this study was to determine TIL for EHRs, full-facepiece respirators, and loose-fitting and tight-fitting powered air-purifying respirators (PAPRs) using NaCl and corn oil aerosols to compare. TIL was measured for two models each of EHRs, full-facepiece respirators, and loose-fitting and tight-fitting PAPRs. After fit testing with a PortaCount (TSI, St. Paul, MN) using the Occupational Safety and Health Administration (OSHA) protocol, eight subjects were tested in the NaCl aerosol chamber first and then in the corn oil aerosol chamber, while another eight subjects tested in the reverse order. Subjects were randomly assigned to one of the two groups. TIL was measured as a ratio of mass-based aerosol concentrations inside the mask to the test chamber while the subjects performed ISO 16900-1-defined exercises using continuous sampling methods. The concentration of corn oil aerosol was measured with one light scattering photometer, alternately, and NaCl aerosol was measured using two flame photometers. Results showed the geometric mean TIL for EHR was significantly ( < 0.05) larger for corn oil aerosol than for NaCl aerosol. EHR models equipped with P100 filters showed relatively smaller TIL values than the same models with N95 filters showing that TIL was inversely related to filter efficiency. Interestingly, TIL was significantly ( < 0.05) larger for NaCl aerosol than for corn oil aerosol for PAPRs, but not for full-facepiece respirators. TIL was inversely related to fit factors of respirator types. Overall, filter efficiency and faceseal leakage determine TIL. The relative trends in TIL for the two aerosols' test methods differ between respirator types indicating that generalization of TIL for respirator types may not be appropriate when using different test agents.
最近,根据国际标准化组织(ISO)测试方法标准 16900-1:2014,对过滤式面罩和弹性半面罩呼吸器(EHR)的总向内泄漏(TIL)进行了测量,结果表明玉米油气溶胶的 TIL 比氯化钠气溶胶大。对于更高防护水平的呼吸器,不同气溶胶的 TIL 测量比较缺乏。本研究的目的是使用氯化钠和玉米油气溶胶来确定 EHR、全面罩呼吸器以及宽松贴合和紧密贴合动力空气净化呼吸器(PAPR)的 TIL,并进行比较。使用氯化钠和玉米油气溶胶分别对每种型号的 EHR、全面罩呼吸器和宽松贴合和紧密贴合的 PAPR 进行了 TIL 测量。在使用职业安全与健康管理局(OSHA)协议的 PortaCount(TSI,明尼苏达州圣保罗)进行拟合测试后,首先将 8 名受试者放入氯化钠气溶胶室进行测试,然后放入玉米油气溶胶室进行测试,而另外 8 名受试者则按相反顺序进行测试。受试者被随机分配到两组中的一组。TIL 是通过使用连续采样方法,在受试者进行 ISO 16900-1 定义的运动时,以面罩内的基于质量的气溶胶浓度与测试室的比值来测量的。交替使用一台光散射光度计测量玉米油气溶胶的浓度,使用两台火焰光度计测量氯化钠气溶胶的浓度。结果表明,EHR 的几何平均 TIL 对于玉米油气溶胶明显(<0.05)大于氯化钠气溶胶。配备 P100 过滤器的 EHR 模型显示出相对较小的 TIL 值,而具有 N95 过滤器的相同模型则显示出 TIL 与过滤效率成反比。有趣的是,对于 PAPR,TIL 对于氯化钠气溶胶明显(<0.05)大于玉米油气溶胶,但对于全面罩呼吸器则不然。TIL 与呼吸器类型的拟合因子呈反比。总体而言,过滤器效率和面部密封泄漏决定了 TIL。两种气溶胶测试方法的 TIL 相对趋势在呼吸器类型之间存在差异,这表明当使用不同的测试剂时,对于呼吸器类型的 TIL 进行概括可能并不合适。