General Description
White or yellowish, finely divided, odorless powder consisting mostly or entirely of calcium sulfate hemihydrate, CaSO4·1/2H2O. Forms a paste when Plaster of Paris (Ca(SO4).1/2H2O) is mixed with water that soon hardens into a solid. Used in making casts, molds, and sculpture. Generally non-toxic.
Reactivity Profile
Plaster of Paris (Ca(SO4).1/2H2O) is non-flammable and non-combustible. Has generally low chemical reactivity but can act as an oxidizing agent under extreme conditions. Decomposes at high temperature to generate toxic oxides of sulfur. Reacts exothermically but slowly with moisture in the air or water to form gypsum CaSO4.2H2O.
