Aluminium sulfate (CAS 10043-01-3)

Aluminium sulfate is a chemical compound with the formula Al2(SO4)3. It is soluble in water and is mainly used as a coagulating agent (promoting particle collision by neutralizing charge) in the purification of drinking water and wastewater treatment plants, and also in paper manufacturing.

It is sometimes used in the human food industry as a firming agent, where it takes on E number E520, and in animal feed as a bactericide. In the USA, the FDA lists it as “generally recognized as safe” with no limit on concentration. Aluminum sulfate may be used as a deodorant, an astringent, or as a styptic for superficial shaving wounds.