As well as in hot baths, gypsum is deposited by lake and sea water, by volcanic vapours, and sulphate solutions in veins. In near-surface exposures, hydrothermal anhydrite in veins is commonly hydrated by groundwater into gypsum. The elements halite and sulphur are also associated with it.
Gypsum goods are not listed as harmful. The long-term adverse medical consequences of gypsum intake do not occur. Wash your teeth and drink lots of water if swallowed. Plaster powders/dust can potentially irritate or irritate the respiratory system in the eyes or delicate skin.