硬指标：ASTM level 2 和 3，

来源: 于 2022-01-12 19:49:51 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

https://www.coronavirus.kdheks.gov/DocumentCenter/View/1416/Understanding-ASTM-Levels-for-Facemasks-PDF---7-30-20

 

https://rdimedical.com/differences-between-astm-level-face-masks-2/

Level 2 and 3 Masks

If you are at a higher risk of being exposed to COVID-19 or more importantly, have been infected, the ASTM level 2 or 3 masks should be worn. 
These will offer the best protection to others from the Coronavirus and ensure you are not cross-contaminating, provided you keep a reasonable distance from others.