I've got a nagging tickle in my throat, and a cough lasting about half a week again. I'm suspecting it is chemistry related because the last time I had this I had caught a few small whiffs of selenium or sodium sulfite or bleach a few days earlier. So here I am now rewinding and replaying the last few toning episodes in the darkroom, thinking the cough is related to the chemistry. Let's just assume for the moment that it is related. So, my questions pretty much boil down to these three: What kind of respirator should I get if my concern over my health means price is not a factor? What kind of respirator should I get if I need to buy something I can easily afford? Is there a possibility that an adequate respirator could be found for darkroom purposes that is also easily affordable? I'd like to hear from experienced people if that's possible!