NEW METHODS FOR QUANTITATIVE RESPIRATOR FIT TESTING

《核管理条例》要求定量测试口罩适合性 原子能设施工人健康保护委员会， 和工人职业安全与健康管理局 接触铅、丙烯腈、无机砷和焦炉废气。 在常规工艺中，邻苯二甲酸二乙基己酯(DOP)已被 用作测试气雾剂，以及 掩模是通过测量光量来确定的 DOP云的散射光强度。然而，DOP拥有 最近被怀疑是一种潜在的人类致癌物质。有建议说 改装连续流动冷凝核计数器(CnC)以适应 使用可更换的滤芯测试负压呼吸器。此外，还有一个 将制定新的测试方案。数控机床的扩容 亚微米大小的细颗粒进入光散射范围，所以 几乎任何无害的细颗粒云都可以用来进行拟合 测试。一种特殊的气溶胶静电计的使用将作为一个 潜在的更简单的测量方法。在探索新的和 简单的适配测试技术，保护系数也将作为 由于呼吸器的性能是预期的，因此颗粒大小的函数 取决于拟合测试生成的颗粒大小分布 设备或实际工业环境。在不存在任何方法 随身携带的一次性口罩，用于适合性测试 二氧化硅、煤或一般有害粉尘。有人提出，一种惰性的， 无毒、超微米大小的粉尘，如石灰石，可通过 一种沸腾床的方法和几种尺寸的粉尘浓度 掩码内部和外部的范围通过使用 空气动力学粒度分析仪。使用商业上可获得的 强调仪器是为了达到可使用的技术 立即由从业者完成。新的FIT测试方法将是 通过测量呼吸器在工业环境中的适用性进行现场评估。

Quantitative respirator fit testing is required by the Nuclear Regulatory Commission for the health protection of workers in atomic installations, and by the Occupational Safety and Health Administration for workers exposed to lead, acrylonitrile, inorganic arsenic and coke oven emissions. In the conventional technique, di-2 (ethyl-hexyl) phthalate (DOP) has been used as the test aerosol, and the concentrations inside and outside the mask have been determined photometrically through measurements of the scattered light intensities from the DOP clouds. DOP, however, has recently been implicated as a potential human carcinogen. It is proposed that a continuous-flow condensation nuclei counter (CNC) be adapted for fit testing negative pressure respirators with replaceable cartridges. Also, a new testing protocol will be developed. The CNC enlarges submicrometer-sized, fine particles into the light scattering range, so virtually any non-hazardous cloud of fine particles can be used for fit testing. The use of a special aerosol electrometer will be studied as a potentially even simpler measurement method. While exploring new and simple fit testing techniques, protection factor will also be measured as a function of particle size since the performance of a respirator is expected to depend on the particle size distribution generated by the fit testing apparatus or the actual industrial environment. No method exists at present for fit testing disposable masks which are worn in the presence of silica, coal, or general nuisance dusts. It is proposed that an inert, nontoxic, supermicrometer-sized dust such as limestone be dispersed by means of a fluidized bed and that the dust concentration for several size ranges inside and outside the mask be determined through use of an aerodynamic particle size analyzer. The use of commercially available instruments is stressed in order to arrive at techniques that can be used immediately by the practitioner. The new fit test methods will be field-evaluated by measuring respirator fits in industrial environments.