Origin and composition
The alum stone is of mineral origin. It can be found in different places in the world, China, Syria, Central America (Panama)..
Known since ancient times, alum stone is a natural stone, which often contains aluminum but not always. It can take several forms:
- natural in the form of a mineral
o recrystallized after quarrying
o in powder form (Potassium alum)
- synthetic or reconstituted (aluminum disulphate and ammonium alum)
Use
The alum stone is astringent, it clogs the sweat glands, the pores and limits perspiration mechanically and therefore it combats the bad odors associated with it.
It is necessary to moisten the stone or underarms before application. And like any deodorant, it is applied to clean armpits, after the shower for example.
Precautions et dangers
Is the aluminium contained in certain alum stones as well as in convetional deodorants dangerous?
In fact, several scientific studies warn against the aluminum salts contained in conventional deodorants (from the cosmetic industry). It is aluminum hydrochlorides that have been singled out several times, not aluminum sulfates.
To date, it is recommended by the National Medicines Safety Agency (ANSM) in France, not to use cosmetic products containing aluminum on damaged skin:
"In conclusion, in order to limit the risk linked to exposure to aluminum, Afssaps recommends to:
• limit the concentration of aluminum in antiperspirant or deodorant products to 0.6%. This value is voluntarily expressed in aluminum, so that it can apply to the different forms used in cosmetic products;
• do not use cosmetic products containing aluminum on injured skin.
Indeed, given the high absorption reported under these conditions, it would be necessary to inform the consumer that antiperspirant or deodorant products should not be used after shaving or in the event of skin damage such as micro cuts. Afssaps recommends that this information appear on the packaging. "
Risk assessment of the use of aluminum in cosmetic products October 2011.
Alternatives exist
If you want to avoid aluminum, there are effective alternatives::
- Particularly pure alum stones without aluminum oxide offered by certain brands. (from Panama)
- Deodorants based on baking soda
- Talc-based deodorants for sensitive skin
- Deodorants based on magnesium hydroxide, etc..
Which alum stone to choose ?
There are different ranges of classic alum stone deodorants. However, it is important to choose your alum stone with good knowledge to take advantage of its antiperspirant, astringent and antiseptic properties.
- The mention "potassium alum" on the packaging is a good idea and is even essential.
- The more translucent an alum stone is, the purer it is, the whiter it is, the more it is synthetic and carries aluminum salts.
