That would depend on the assumptions, those being: - context i.e. clinical setting vs on the street - type of mask - skill set of those using the equipment

That would depend on the assumptions, those being: - context i.e. clinical setting vs on the street - type of mask - skill set of those using the equipment For example, knives are very effective in surgery when they are: - in a surgical theatre - a scapel - used by a surgeon I don't suggest doing surgery in the street with a knife from your kitchen draw used by a teenager.