You may need to research OSHA a bit for each contaminate in the air! In case of certain chemicals "Supplied Air" is your only option! But if it were ME... NO WAY I'd be walking around #Ohio without one of these puppies! (or several other states) Like I said... you may need to go "Full moon suit" And BTW.... OSHA REQUIRES "Fit Testing" for a reason! If you can breathe AT ALL when your respirator inlet is plugged up, you are NOT PROTECTED AT ALL! You hairy guys may wanna shave! And remember.... HCL Acid is neutralized by Sodium Bicarbonate! You may find this useful when the rain falling from the sky is actually HCL Acid! DO YOUR RESEARCH!