Dude, I've been in construction 30 yrs as an insulator, drywaller, taper and painter, aswell as autobody paint habby and I have been wearing various masks for sometimes days on end for all that time, and OSHA is up our asses about how often to wear them and masks have even gotten better since my early days and I have never ever contracted anything at all as far as you carbon monoxide or bacteria garbage you're crying about. Quit being so dramatic, it's embarrasing.