'fit testing'

never come across this procedure before.  An obnoxious tasting substance is sprayed inside the hood whilst we breathe through the mask, contort around in various positions and talk. 
If you can taste or smell it then the mask doesn't fit correctly. 
Not sure however what you then do as the mask is our only protection from breathing something in. The hood is purely for testing purposes. 
Suggest stay at home if at all possible.