potassium aluminum sulfate dodecahydrate is an inorganic compound consisting of the double salt (also called alum) of aluminum and potassium, with the sulfate group attached to two post-transition metal ions. It is a member of the alum family of compounds, which also includes aluminum ammonium sulfate and aluminum sodium sulfate.
Alum dissolves in water to form a solution. It is used to deodorize clothing, for astringents and as an ingredient in paper-making. It is also used to harden photographic emulsions and to prepare a solution for sizing paper and ceramic glazes. Alum is found naturally in the alum-producing minerals alunite and kalinite. It can also be produced synthetically by combining aqueous aluminum sulfate with aqueous potassium sulfate.
It is a soluble solid with the formula KAl(SO4)2
Potassium aluminum sulfate is toxic if ingested in large doses and has been known to cause gum necrosis, bladder hemorrhage, and encephalopathy. It is also an irritant, and it may be corrosive to eyes and mucous membranes. It is soluble in water and alcohol. It is incompatible with steel, aluminium, copper and zinc, bases, and strong oxidizing agents.
The compound is a fire hazard and may release toxic fumes upon ignition. It is a strong irritant, and should be stored in a dry place in tightly closed containers. It is not stable when exposed to air, forming hydrochloric acid and hydrogen sulfate.