The US Centers for Disease Control and Prevention has changed its mask guidelines to recommend that people "wear the most protective mask you can that fits well and that you will wear consistently." The agency describes well-fitting respirators approved by the National Institute of Occupational Safety & Health (NIOSH) -- such as N95 masks -- as offering "the highest level of protection."


원문출처 : https://www.cnn.com/2022/01/15/health/mask-guide-faq-n95-kn95-wellness/index.html