FWIW- I always wear nitrile gloves in the darkroom, have good ventilation, and wear a mask when mixing powders. These measures are common sense. Some of the things in my darkroom are toxic, so I eliminate as much exposure as possible.
Common sense in personal protection, safe handling, responsible storage, and proper disposal of chemicals goes a long way, very much farther IMHO than worrying about the individual toxicity of a given compound. That said, it behooves one to know what one is handling, as well.