See what brands are in the store, then look up the MSDS for that brand. I can tell you that most of them have traces of other stuff as well besides Calcium Hydroxide, like Magnesium Hydroxide, Magnesium Oxide, Calcium Carbonate, and Crystalline Silica(Quartz).
If these things are okay to use or not, I really don't know.
“Surrender is inner acceptance of what is without any reservations. If you have lived long enough, you will know that things “go wrong” quite often. It is precisely at those times that surrender needs to be practiced if you want to eliminate pain and sorrow from your life.”
Eckhart Tolle