Sandia National Laboratories, Albuquerque, NM, United States of America.
PLoS One. 2021 Apr 8;16(4):e0248859. doi: 10.1371/journal.pone.0248859. eCollection 2021.
In response to personal protective equipment (PPE) shortages in the United States due to the Coronavirus Disease 2019, two models of N95 respirators were evaluated for reuse after gamma radiation sterilization. Gamma sterilization is attractive for PPE reuse because it can sterilize large quantities of material through hermetically sealed packaging, providing safety and logistic benefits. The Gamma Irradiation Facility at Sandia National Laboratories was used to irradiate N95 filtering facepiece respirators to a sterilization dose of 25 kGy(tissue). Aerosol particle filtration performance testing and electrostatic field measurements were used to determine the efficacy of the respirators after irradiation. Both respirator models exhibited statistically significant decreases in particle filtering efficiencies and electrostatic potential after irradiation. The largest decrease in capture efficiency was 40-50% and peaked near the 200 nm particle size. The key contribution of this effort is correlating the electrostatic potential change of individual filtration layer of the respirator with the decrease filtration efficiency after irradiation. This observation occurred in both variations of N95 respirator that we tested. Electrostatic potential measurement of the filtration layer is a key indicator for predicting filtration efficiency loss.
针对 2019 年冠状病毒病导致美国个人防护设备 (PPE) 短缺的问题，对两种 N95 呼吸器模型进行了评估，以确定其在伽马射线辐射消毒后的重复使用情况。伽马消毒是 PPE 重复使用的一种有吸引力的方法，因为它可以通过密封包装对大量材料进行消毒，从而提供安全性和后勤方面的好处。桑迪亚国家实验室的伽马辐照设施被用于将 N95 过滤面罩呼吸器辐射到 25 kGy（组织）的灭菌剂量。气溶胶颗粒过滤性能测试和静电场测量用于确定辐射后的呼吸器的功效。两种呼吸器模型在辐射后都表现出颗粒过滤效率和静电势的统计学显著下降。捕获效率的最大降幅为 40-50%，峰值出现在 200nm 粒径附近。这项工作的主要贡献是将单个过滤层的静电势变化与辐射后过滤效率的下降相关联。我们测试的两种 N95 呼吸器都出现了这种观察结果。过滤层的静电势测量是预测过滤效率损失的关键指标。
