Ole said:
Besides, that bit about toxicity is debatable, too
Yes, I see the smiley...
...but there's no real debate about the toxicity of pyrogallol. The debate is over magnitude of risk. All of us deal with poisons daily -- gasoline, for instance, is a known poison and carcinogen, and "known to the State of California to cause genetic damage and harm to unborn infants" or something like that wording; it's also flammable enough that the toxicity is very much secondary.
In a photo darkroom, far more people will have trouble with metol than with pyrogallol; metol isn't quite as toxic as pyro, but is far more commonly used (and it's not *that* much less toxic). I have a bottle of potassium dichromate, 1% solution, behind me; it's used as a contrast enhancer in cyanotypes, and is easily the most toxic and hazardous chemical I have around (much worse than the HC-110, stop bath or fixer concentrates, borax, etc., and chemically more hazardous than any of the solvents and lubricants I keep near my lathe). I have the bottle clearly marked, and there are never children in my house, so I don't worry much about it, other than to take great care to keep it off my skin when I use a drop for a cyano print that needs it.
No, I wouldn't want to put my hands in a pyro developer -- but I've spent a lot of hours with my (unprotected) hands in Dektol when I printed in high school and college, without incident. I wouldn't do that without gloves, now, either. I have no sensitivity that I'm aware of, but why push things?
With pyro, the precautions needed are the same as for any other photo chemical: don't drink it (and by extension, don't eat or drink *anything* in the darkroom or chemical prep area, just as you wouldn't eat or drink in a chemistry lab), avoid skin contact where practical, clean up spills properly, and dispose of chemicals properly (which, for most, is simply a matter of adequate dilution when disposing into the drain). And last, don't get yourself all worked up over it -- constant worry will kill you a lot faster than anything in your darkroom, if you don't do anything really stupid.