kaduva:jupiter2: This chart shows the best and worst face masks Sourceto clarify about masks with
kaduva:jupiter2: This chart shows the best and worst face masks Source to clarify about masks with vents:they are not intended to prevent spread of pathogens. they exist solely to protect the wearer. they are intended for e.g. building sites or industrial settings where there may be dust & particles etc. in the air - i.e. they do a great job at filtering what comes in through the mask (hence the high stats), but they have a handy vent that opens when you breathe out. there is absolutely no filtering on the air coming out through that vent (because in the setting they’re designed for, there’s no need for it). do not wear these masks, they are almost useless in terms of preventing the spread of the virus. -- source link