Aluminum Salts in Antiperspirants.

Aluminum is the third most abundant element in the earth's crust (8%), after oxygen and silicon, and can be recycled ad infinitum. Highly reactive, it is generally present in nature in oxidized form or complexed with other elements.

In skin care, aluminum is most often used in salt form. Generally speaking, this is the association of an aluminum cation (positive ion) Al3+ with three chlorine anions (negative ions) Cl-, the whole forming a neutral assembly.

A deodorant with aluminum salt is used to combat perspiration. They can be found on INCI lists under the following names: aluminum chloryde, aluminum chlorohydrate, aluminum chlorydrex, aluminum sesquichlorohydrate, aluminum zirconium.

Furthermore, according to European cosmetics regulations, the concentration of aluminum salts in antiperspirants must not exceed 20%, which corresponds to a content of around 5% aluminum.

How do they work? When applied to the skin, aluminum salts precipitate and combine with dead skin, establishing plugs that obstruct the sweat glands and thus block perspiration. Furthermore, they are bactericides. They eliminate the many bacteria present in the armpits, the source of unpleasant odors.

Note: Is there a difference between antiperspirant and deodorant?  In everyday language, the term “deodorant” is more commonly used than “antiperspirant”. It's sometimes referred to as a deodorant with aluminum when in fact it's an antiperspirant.

Aluminum salts in antiperspirant products are currently the subject of criticism from consumers and the media alike. They are suspected of promoting the onset or development of certain diseases, notably breast cancer. Let's take a look at the various studies and opinions on this subject.

• The early 2000s saw a steady rise in breast cancers among younger and younger subjects. The majority of tumors are located near the armpit, which has prompted researchers and authorities to take a closer look at the composition of deodorants.

• Over the last ten years, several studies have been carried out in Switzerland by professor and oncologist André-Pascal Sappino and Dr. Stefano Mandriota. They exposed mouse mammary cells to aluminum salts (more precisely, AlCl3). The conclusions are clear: aluminum salts promote the rapid development of sometimes aggressive tumors, forming metastases.

• In June 2017, an Austrian study showed that women using deodorant with aluminum numerous times a day on shaved armpits before the age of 30 had a doubled risk of breast cancer.

• Despite this, an ANSM (French National Agency for the Safety of Medicines and Health Products) report published in 2019 came to the following conclusion: “the existing data do not allow us to establish a body of arguments in favor of a causal link between aluminum and breast cancer”, but they “do not allow us to rule it out definitively”. 

• Furthermore, the SCCS (European Scientific Committee on Consumer Safety) issued a report in 2019 attesting to the very low cutaneous absorption (of the order of 0.00052%) of aluminum salts, even on shaved or depilated skin. According to this document, the aluminum present in antiperspirants remains outside the body, preventing any toxic effect. The SCCS therefore considers that exposure to aluminum via daily applications of cosmetics containing it does not increase the body's aluminum load from other sources. The concentration of aluminum “absorbed” through the skin would be far too low to play a role in the development of breast cancer.

In conclusion, it is difficult to form an opinion on the harmful nature of deodorants with aluminum. As a precautionary measure, we at Typology exclude these compounds from our formulas.

In March 2020, the CSSC introduced several dosage recommendations:

• 6.25% in non-spray deodorants;

• 10.60% in sprays;

• 2.65% in toothpastes;

• 0.77% in lipsticks.

The ANSM (French Agency for the Safety of Medicines and Health Products) recommends a much lower concentration: no more than 0.6% aluminum salts in cosmetic products.

However, it's important to point out that these remain guidelines: they do not lead to a change in regulations!

Even if the link between breast cancer and aluminum salts is not clearly established, many consumers are turning to antiperspirants without aluminum. Here are some of them:

• Baking soda-based antiperspirants.

  An alternative in non-aluminum deodorants is sodium bicarbonate. It has naturally absorbent, anti-odorant and anti-inflammatory properties to soothe irritated skin.

• Clays.

  Thanks to their microporous structures, some clays such as diatomaceous earth powder are drying agents that can absorb their weight in moisture. Their antibacterial action also acts on the bacteria present on the skin and thus limits the appearance of bad odors and acts as aluminum-free deodorant. 

What about alum stone? Alum stone is not as natural as its name suggests. It can even be a 100% synthetic stone, made from Ammonium Alum or synthetic Ammonium Sulfate, a by-product of the nylon chemical industry. In any case, natural or synthetic, alum stone contains aluminum salts.

• Scientific Committee on Consumer Safety : SCCS/1613/19 (2019)

• Mandriota SJ, Tenan M, Ferrari P, Sappino A-P. Aluminium chloride promotes tumorigenesis and metastasis in normal murine mammary gland epithelial cells. Int J Cancer. (2016)

• Willhite CC, Karyakina NA, Yokel RA, et al. Systematic review of potential health risks posed by pharmaceutical, occupational and consumer exposures to metallic and nanoscale aluminum, aluminum oxides, aluminum hydroxide and its soluble salts. Crit Rev Toxicol. (2014)

• Evaluation du risque lié à l’utilisation de l’aluminium dans les produits cosmétiques - Point d’information - ANSM : Agence nationale de sécurité du médicament et des produits de santé.