ASBESTOS FIBER COLLECTION BY NIOSH-APPROVED RESPIRATORS

这项研究的目标是使用石棉气雾剂来研究 经认证与石棉一起使用的呼吸器的性能。一个 经认证的空气净化口罩的代表性样本将是 测试过。由于石棉是一种非常危险的材料，而且既然 它说，呼吸器被广泛用于保护工人免受石棉的伤害 非常重要的是，经过认证的呼吸器的性能符合预期。 不幸的是，目前的NIOSH认证程序不需要 对呼吸防护口罩进行石棉测试。这就是我们的目标 调查这一事件和其他可能事件的意义的研究 认证程序中的缺陷。 防石棉口罩的性能将与 对于二氧化硅，NIOSH认证中使用的标准粉尘 程序。呼吸器穿透性将在恒定流动下进行测量 条件，就像在认证测试中所做的那样，并且在循环流动下， 模拟实际使用条件。将执行三个重复测试 对于每种测试气溶胶和流型的组合，这样就可以进行十二次测试 将对每个呼吸器进行检查。将对测量结果进行分析 通过标准的统计技术，包括方差分析，给出 气雾剂类型、流型和呼吸器对性能的影响 模特。此外，还将进行探索性测试，以评估 高粉尘负荷和温湿度升高对大气环境的影响 呼吸器性能，以比较按相测量的穿透性 对比和扫描电子显微镜，并比较其性能 电动和非电动空气净化呼吸器。

The goal of this research is to use an asbestos aerosol to investigate the performance of respirators certified for use with asbestos. A representative sample of certified air-purifying respirators will be tested. Since asbestos is a very hazardous material, and since such respirators are widely used to protect workers from asbestos exposure, it is very important that certified respirators perform as expected. Unfortunately, the present NIOSH certification procedure does not require that respirators be tested against asbestos. It is the goal of this research to investigate the significance of this and other possible deficiencies in the certification procedure. The performance of the respirators against asbestos will be compared to that for silica, the standard dust used in the NIOSH certification procedure. Respirator penetration will be measured under steady flow conditions, as is done in the certification test, and under cyclic flow, to simulate actual use conditions. Three replicate tests will be performed for each combination of test aerosol and flow pattern, so that twelve tests will be performed for each respirator. The measurements will be analyzed by standard statistical techniques, including analysis of variance, to give the effects on performance of aerosol type, flow pattern, and respirator model. In addition, exploratory tests will be performed to assess the effects of high dust loading and elevated temperature and humidity on respirator performance, to compare penetration as measured by phase contrast and scanning electron microscopy, and to compare the performance of powered and non-powered air-purifying respirators.