I've certainly read that about quicklime.You can't use hydrated lime on the floor of a chicken coop or barn or anywhere else people or animals walk around & can get in it. It will irritate their respiratory system and burn their skin & feet. It can blind them if medical attention isn't provided.This stuff gets hot when you add water.
But I thought hydrated lime was safe, because the water has already been added and the heat-producing reaction is over?