When an antiperspirant claims to be “aluminum-free,” they are saying it does not contain aluminum chlorohydrate, aluminum chloride, aluminum hydroxybromide or aluminum zirconium—all forms of aluminum commonly used in antiperspirants and deodorants. To stop the flow of sweat to your skin’s surface, the aluminum plugs sweat ducts in the top layer of your skin stopping the natural flow of sweat to your skin’s surface.
This aluminum can also be absorbed into your body where it can then build up as part of your body burden. Alzheimer’s disease and cancer are two illnesses known to be associated with aluminum exposure.
The aluminum in crystal deodorant stones is a different type of aluminum, called alum. The most common form is potassium alum, also known as potassium aluminum sulfate.
Potassium alum (and other alums) is a natural mineral salt made up of molecules that are too large to be absorbed by your skin. They form a protective layer on your skin that inhibits the growth of odour-causing bacteria.
Biork™´s crystal deodorant lasts longer than you are used to from other deodorants. In addition, the potassium alum contains important minerals. Of course, all ingredients have been dermatologically tested.