Can someone explain to me how a mask that (according to government) can not stop smoke particles as small as 1 millionth of a meter, but will stop a virus that is .070 th .160 millionth of a meter.
Can someone explain to me how a mask that (according to government) can not stop smoke particles as small as 1 millionth of a meter, but will stop a virus that is .070 th .160 millionth of a meter.
