Thanks to everyone for the great information! In addition to a clean mask, I use motorcycle goggle "anti-fog" treatment to keep my mask from fogging. This works great. I also purchase jumbo 2.5 gallon zip-lock bags that I keep my mask in, on scene, until I mask up to go in. They are disposable and will keep dirt, saw dust, and other yuck out of the mask until I need it on my face - clean.
Hey To all of YOU'NS on cleaning of the SCBA's facepiece I fave found from a local industrial janiatorial source a product that is totally BIO-DEGRADEABLE that you mix in CLEAN WATER contains NO ALCOHOL is SOLAVENT FREE
It is called SANI-T 10 made by SPARTAN INDUSTRIES. I first rinse out the facepiece with plain water then spray the cleaner the wipe dry with a dry towel. IT IS TOTALLY ANTIBACTIRAL MRSA VERSA HEP ABC HIV STAPH. It leaves no after taste or odor even if you put in use right after cleaning.