holding up three different kinds of respirators with negative space

2019ncov and antipollution background buying care chinese clip coronavirus cough cov cover covid19 crisis daily disease dust everyday face ffp1 ffp3 filter friendly gray grey hand hazard health hour mask material metallic multiple n95 need negative new nonvalved normal nose objects outbreak pandemic pathogen piece pm25 pollution respirator reuse sars skin sneeze space texture the three types use valve valved virus yellow