Injecting bleach into the mouth is a common step in a root canal procedure.

I don't know if its true, it just feels true: People with excruciating back pain are in general argumentative over stupid shit...

I wear a N-95 with a 2 or 3 layer mask outside to seal the edges.

I also have a heavy duty gold visor air tight helmet used for oil well fires. I haven't had the occaision to use it yet. Besides I don't have the insulated oxygen tank or rebreather but I have the fireproof pants and coat.