Aluminium sulfate is sometimes used to reduce the pH of garden soil, as it hydrolyzes to form the aluminium hydroxide precipitate and a dilute sulfuric acid solution.
Aluminium sulfate is the active ingredient of some antiperspirants; however, beginning in 2005 the US Food and Drug Administration no longer recognized it as a wetness reducer.
Aluminium sulfate is usually found in baking powder.
In construction industry it is used as waterproofing agent and accelerator in concrete. Another use is a foaming agent in fire fighting foam.
It is also used in styptic pencils, and pain relief from stings and bites; it is the active ingredient in popular pain relief products such as Stingose.