They are soluble in water and sweetish in taste. Any  form of aluminum sulfate is called “alum,” The type of alum used for pickling  is potassium alum, KAl(SO4)2•12H2O. Sodium aluminum sulfate is a type of alum that is used in commercial baking powder.

Commonly used in: 
Pickles and baking powder.

Health Benefits: 
All forms of alum can cause irritation of the skin, mucous membrane and breathing alum can cause lung damage if excessively used.