Amidol is certainly toxic - in its powdered form it is easily inhaled. I use a mask and gloves when mixing to reduce exposure. Mind you I also use a mask and gloves when using paint stripper. If sensible precautions are taken then harmful effects from using admidol (indeed any photographic chemical) can be greatly reduced.
In fact, the chemical that did me the most damage was 10% sulphuric acid. I spilt some on my tee shirt and it ended up full of holes.