I think if you are really concerned then you have to wear gloves if you are dealing with colour chemicals. I used to suffer from small splits in the skin on my right hand only which is the hand I used to agitate colour prints in the nova deep-tank processor. The developer was OK but the bleach fix was pretty savage stuff and it felt like a hot pin had been stuck into my fingers when splashes got to the splits.

Except for things like selenium toner I don't think that there are any problems with chemical smells although some find them objectionable. With selenium there is a warning on the concentrate anyway about using it in confined spaces.

When in their working solution strength photo chemicals are pretty benign so long as they are not ingested and if you do, (I would say unlikely except in an accident) it is a pretty stupid thing to do anyway.