You shouldn't breath the dust, or eat it by the spoonful, but it is a common ingredient in foods and the principle ingredient in antacids that promote themselves as supplying calcium. Lime is another matter. You shouldn't eat it or get it in your eyes. First aid for eyes is to wash with cold water. But don't go overboard.
Slaked lime is added to many foods to counteract excess acidity.
It is used in pickling, for example. Lye is the most caustic of the alkalis we will use. You should definitely keep it off skin, out of eyes, and out of mouth. Skin should be washed if you get a little careless. If you get it in your eyes, you should wash them immediately with cold water and call a hospital.