Potassium alum

Other names: Kamenetz, Salt crystal

Harm score: 2 (Derivatives of natural substances)

Potassium alum, also known as alum or salt crystal, is a potassium disulfide mineral found in nature. It is a white to colourless powder that dissolves very well in water and has astringent, i.e. astringent, effects. Potassium alum was used in ancient Egypt not only for its astringent properties but also as an antiperspirant and deodorant. The substance is still widely used in the cosmetics and pharmaceutical industries.

The products in which potassium alum can be found are very diverse. For example, various antiperspirants and deodorants, where it acts as a blocker of the sweat glands and thus prevents sweat and unpleasant odours. It is also used in aftershave soothing products for men, as it has the ability to shrink pores and soothe irritated skin. As for other areas, alum is used in the food industry as a preservative and stabiliser, in the cloth industry as a dyeing and fixing agent and in the leather industry for its astringent properties. Other uses include water purification and the production of certain types of cement. Such a wide range of uses makes potassium aluminium one of the most important chemical compounds used in industry.