Evaluation and risk communication of effects of alcohol exposure on disposable procedure masks and portable air purifiers

As electret technology can drastically improve the filtration efficiency of disposable procedure masks and portable air purifiers, it is widely used to prevent the airborne transmission of SARS-CoV-2. Furthermore, alcohol disinfectants are now widely used in offices, hospitals, and homes to prevent contact infection; hence, there is a concern that alcohol exposure may inactivate electret. In this study, 5 types of high-efficiency particulate air filter (HEPA) air purifiers—of which, one was made of fiberglass HEPA filter—14 types of cubical masks, and 11 types of pleated masks available to Japanese citizens were subjected to discharge according to the alcohol exposure protocol based on ISO (International Organization for Standardization) 16890, and changes in filtration efficiency and pressure drop were measured before and after the discharge. The results revealed that 17 (68%) of the 25 masks exhibited a significant decrease in filtration efficiency; this decrease due to discharge depended on the filter material. However, masks of polypropylene, polyethylene, and poly-vinylidene-difluoride composite fiber materials exhibited no significant decrease in filtration efficiency. In addition, 4 (80%) of the 5 HEPA filters showed a 40–64% decrease in filtration efficiency, while no decrease in filtration efficiency was observed for the fiberglass HEPA filter. Our survey (n = 500 Japanese adults, including 30 healthcare professionals) revealed that approximately 90% of the general public was unaware that the performance of masks and air purifiers could be degraded by direct spraying of alcohol—for disinfection purposes—or vapor exposure. Furthermore, 36% of the surveyed healthcare professionals indicated that they had sprayed alcohol directly on their masks. Therefore, based on the results of this experiment, we examined effective consumer warnings that could be utilized on the product labels and in the instructions. The results showed that it would be more effective to detail the extent and duration of the adverse effects of disregarding the precautions.

驻极体（electret）技术可大幅提升一次性手术口罩与便携式空气净化器的过滤效率，因此被广泛用于阻断严重急性呼吸综合征冠状病毒2型（SARS-CoV-2）的空气传播。当前，酒精消毒剂在办公室、医院及家庭中被广泛用于预防接触传播，由此引发一项担忧：酒精暴露可能会使驻极体材料失活。
本研究针对日本民众可购得的5款高效空气过滤器（High Efficiency Particulate Air Filter，HEPA）空气净化器（其中1款采用玻璃纤维HEPA过滤器）、14款立体口罩及11款折叠式口罩，依照基于国际标准化组织（International Organization for Standardization，ISO）16890的酒精暴露规程进行处理，并测量了处理前后的过滤效率与压降变化。
结果显示，25款口罩中有17款（68%）的过滤效率出现显著下降，该下降程度与过滤器材质相关。其中，采用聚丙烯、聚乙烯及聚偏二氟乙烯复合纤维材质的口罩，其过滤效率未出现显著变化。此外，5款HEPA过滤器中有4款（80%）的过滤效率下降了40%至64%，而玻璃纤维HEPA过滤器未出现过滤效率降低的情况。
本调研覆盖500名日本成年人（含30名医护人员），结果表明约90%的普通民众并不知晓，为消毒目的直接喷洒酒精或暴露于酒精蒸汽中，会降低口罩与空气净化器的性能。另有36%的受访医护人员表示，他们曾直接在口罩上喷洒酒精。
基于本实验结果，我们研究了可用于产品标签及使用说明书的有效消费者警示方案。结果显示，详细说明忽视防护注意事项可能带来的不良影响范围与持续时间，可使警示更具实效。