Fitting characteristics of eighteen N95 filtering-facepiece respirators
Fitting characteristics of eighteen N95 filtering-facepiece respirators
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DOI：
10.1080/15459620490433799
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发表时间：
2004-04-01
影响因子：
2
通讯作者：
Jensen, PA
中科院分区：
文献类型：
--
作者：
Coffey, CC;Lawrence, RB;Jensen, PA
用4个性能指标评价了18款N95口罩的拟合特性：(1)第5百分位模拟工作场所保护系数(SWPF)值，(2)移位平均SWPF值，(3)辅助分配误差的h值。还评估了适合性测试对呼吸器提供的保护水平的影响。这些口罩在25名不同脸型的受试者身上进行了测试。模拟的工作场所保护系数值由6次总渗透(面封泄漏加过滤器渗透)测试确定，并在每次测试之间重新穿上，用于指示呼吸器的性能。使用了五种匹配测试：Bitrex(TM)、糖精、针对过滤器渗透进行修正的生成气雾剂、针对过滤器渗透进行修正的PortaCounr(R)Plus以及带有N95-Companion(TM)附件的PortaCount Plus。在不进行匹配测试的情况下，所有模型的第5百分位数SWPF合计为2.9，单个模型的值在1.3到48.0之间。通过适合性测试通常会增加保护措施。此外，还计算了每个呼吸器的h值。H值已被确定为将获得适当保护水平的个人的总体比例(即，SWPF大于或等于10，这是半面式呼吸器的预期保护级别)，当根据制造商的说明选择并佩戴呼吸器(包括用户的密封性检查)而不进行适配测试时。所有模型的h值加在一起是0.74(即，所有Donnings的74%导致了足够的保护水平)，单个模型的h值在0.31到0.99之间。只有三款机型的h值超过0.95。通过排除为不合格的测试对象/呼吸器组合确定的SWPF值，实现了更高的SWPF值。H值较低的口罩型号的改善最大。使用移位平均值和分配误差的概念来测量呼吸器的性能也得到了类似的结果。提供最高级别保护的是，通过了具有良好适配特性的呼吸器的适配测试。
Four performance measures were used to evaluate the fitting characteristics of 18 models of N95 filtering-facepiece respirators: (1) the 5th percentile simulated workplace protection factor (SWPF) value, (2) the shift average SWPF value, (3) the h-value, aid (4) the assignment error. The effect of fit-testing on the level of protection provided by the respirators was also evaluated. The respirators were tested on a panel of 25 subjects with various face Sizes. Simulated workplace protection factor values, determined from six total penetration (face-seal leakage plus filter penetration) tests with re-donning, between each test, were used to indicate respirator performance. Five fit-tests were used: Bitrex(TM), saccharin, generated aerosol corrected for filter penetration, PortaCounr(R) Plus corrected for filter penetration,and the PortaCount Plus with the N95-Companion(TM) accessory. Without fit-testing, the 5th percentile SWPF for all models combined was 2.9 with individual model values ranging from 1.3 to 48.0. Passing a fit-test generally resulted in an increase in protection. In addition, the h-value of each respirator was computed. The h-value has been determined to be the population fraction of individuals who will obtain an adequate level of protection(i.e.. SWPF greater than or equal to 10, which is the expected level of protection of half-facepiece respirators) when a respirator is selected and donned (including a users seal check) in accordance with the manufacturer's instructions without fit-testing. The h-value for all models combined was 0.74 (i.e., 74% of all donnings resulted in an adequate level of proteclion), with individual model h-values ranging from 0.31 to 0.99. Only three models had h-values above 0.95. Higher SWPF values were achieved by excluding SWPF values determined for test subject/respirator combinations that failed a fittest.. The improvement was greatest for respirator models with lower h-values. Using the concepts of shift average and assignment error to measure respirator performance yielded similar results. The highest level of protection was provided by, passing a fit-test with a respirator having good fitting characteristics.