Evaluation of Respirators for Engineered Nanoparticles

描述(申请人提供)：由于纳米材料独特的物理化学特性和广泛的应用，这些材料的产量不断增加。目前的科学证据表明，与化学成分相似的大颗粒相比，纳米颗粒可能具有更强的生物活性。因此，采取措施将工人的暴露降至最低是谨慎的。当工程和行政控制不能充分防止暴露在空气中的纳米材料时，建议使用NIOSH认证的N95和P100呼吸器。经认证的呼吸器的指定保护系数(APF)考虑了(1)颗粒通过过滤器的穿透和(2)面/密封界面区域周围的泄漏所导致的总向内泄漏。已有文献报道了使用标准测试气雾剂进行过滤效率的初步实验室测试。目前还没有关于实际工程纳米颗粒的呼吸器过滤效率的研究报告。初步测试也仅限于过滤器的渗透特性。目前还没有关于纳米颗粒面封泄漏的报告。因此，关于NIOSH认证的呼吸器用于职业暴露于工程纳米颗粒的呼吸保护的性能的信息不足。这项拟议研究的总体目标是评估N95和P100呼吸器对工程纳米颗粒的呼吸保护性能。这些呼吸器的过滤器穿透和面封泄漏都将使用经过改造的纳米颗粒进行表征。由于许多纳米颗粒具有与标准测试颗粒不同的物理特性，我们还计划对工程纳米颗粒的物理和传输特性进行表征。还将制定一个理论框架，将这些纳米颗粒的关键物理和运输特性与过滤过程联系起来。这项拟议的研究将对呼吸器工程颗粒防护的研究产生积极的影响，为在呼吸器测试、采样器的设计和开发以及暴露评估中使用现实工程颗粒提供一种研究方法和工具。 公共卫生相关性：拟议研究的总体目标是评估N95和P100口罩对工程纳米颗粒的呼吸保护性能。这些呼吸器的过滤器穿透和面封泄漏都将使用经过改造的纳米颗粒进行表征。还将制定一个理论框架，将这些纳米颗粒的关键物理和运输特性与过滤过程联系起来。这项研究将为NIOSH认证的呼吸器在职业环境中限制暴露于工程纳米颗粒的建议提供必要的信息。

DESCRIPTION (provided by applicant): Production of nanomaterials has increased continuously because of the unique physicochemical characteristics and extensive applications of these materials. Current scientific evidence indicates that nanoparticles may be more biologically reactive than larger particles of similar chemical composition. Therefore, it is prudent to take measures to minimize worker exposure. Respirators, including NIOSH-certified N95 and P100 respirators, are recommended when engineering and administrative controls do not adequately prevent exposures to airborne nanomaterials. The assigned protection factor (APF) of a certified respirator takes into account total inward leakage caused by (1) penetration of particles through the filter, and (2) leakage around the face/seal interface region. Preliminary laboratory tests of filtering efficiency using standard test aerosols have been reported in the literature. There are no reported studies on respirator filtration efficiency for actual engineered nanoparticles. The preliminary tests also were limited to the filter penetration characteristics. No reports on face seal leakage are available for nanoparticles. Therefore, there is insufficient information on the performance of NIOSH-certified respirators for respiratory protection of occupational exposure to engineered nanoparticles. The overall objective of the proposed study is to evaluate the performance of N95 and P100 respirators for respiratory protection of engineered nanoparticles. Both the filter penetration and face seal leakage of these respirators will be characterized using engineered nanoparticles. Because many nanoparticles have physical properties different from standard test particles, we also plan to characterize the physical and transport properties of engineered nanoparticles. A theoretical framework to relate the key physical and transport characteristics of these nanoparticles to the filtration process will also be developed. The proposed study will have a positive impact on the research of respirator protection of engineered particles by providing a research approach and tool to use realistic engineered particles in the respirator test, design, and development of samplers, and exposure assessment. PUBLIC HEALTH RELEVANCE: The overall objective of the proposed study is to evaluate the performance of N95 and P100 respirators for respiratory protection of engineered nanoparticles. Both the filter penetration and face seal leakage of these respirators will be characterized using engineered nanoparticles. A theoretical framework to relate the key physical and transport characteristics of these nanoparticles to the filtration process will also be developed. This study will develop necessary information for recommendations of NIOSH-certified respirators to limit exposure to engineered nanoparticles in occupational environments.