I sent an email to the mycology professor at my alma mater, UCDavis, to get the expert opinion on this. While doing so, I remembered that my professor (of Mycology) tried to make sure than no one opened anything in the lab that contained black bread mold (Rhizopus) because it makes so many spores that is will totally contaminate the lab, and make it hard to get a pure culture. It was a total dream, because at least once a quarter someone would already have unleashed the hounds before they realized that everyone else in the lab was yelling, "DON'T OPEN THAT!!!" Hios other rule was that any petrie dish that had Rhizopus in it was to be put directly into the autoclave tub, without being opened. Because the heat and pressure of an autoclave will kill anything, spores included. Its how they sterilize medical instruments, etc. They make up trays with all the instruments for a certain procedure, wrap them in a freshly laundered surgical drape, clamp it shut with a hemostat, and autoclave it. Than you can open it with gloved hands using the hemostat, and everything stays sterile. But the point is, they autoclave the surgical drapes, which are COTTON FABRIC, and they seem to come out fine. I don't know if it causes wear on the fabric or not. Anyone here a doctor or nurse or such who knows about autoclaving?