More than twenty-five aluminium compounds can be used in cosmetic products,” explains the French Agency in a recent safety assessment of the risks linked to the use of aluminium in cosmetic products. “The aluminium chlorohydrate is one of the most widely used, especially as antitranspirant,” the agency adds.

Since the beginning of the 2000s, several studies have been focusing on the risks related to these substances, in particular because of the role of aluminium in the Alzheimer’s disease. Since 2004 and the publication of the works of Darbre et al. (2003), the possible link between the use of underarm cosmetics such as aluminum-based antiperspirants and breast cancer made the headlines.

So far, previous attempts to assess the risk related to aluminium in cosmetic products collided with the lack of relevant data, and the latest assessment by the French agency was made possible thanks to a recent dermal absorption study provided by the cosmetics industry.

Dermal absorption

This in vitro study conducted on human skin allowed to estimate the quantities of aluminium absorbed via a daily exposure to an antiperspirant containing 20% of aluminum chlorohydrate (2.5% aluminum) to a rate of 0.5% in case of the exposure of intact skin, and to a rate of 18% in the case of damaged skin exposure.

The margin of safety is 20 in intact skin exposure conditions and less than 1 in the case of damaged skin exposure conditions, the Afssaps says.

Neurotoxicity

Under such circumstances, what are the possible effects of exposure to aluminium?

Repeated dose administration in laboratory animals showed that several aluminium containing compounds have the potential to produce neurotoxicity and to affect the male reproductive system. Human effects (neurotoxicity, anemia…) are also known in patients undergoing dialysis and thereby chronically exposed parenterally to high concentrations of aluminium, as well as in premature infants fed by parenteral route.

However, the animal studies did not show any carcinogenic potential. Furthermore, epidemiological data “do not establish any conclusive link between dermal aluminum exposure and development of cancer,” says the agency.

Consumer safety not ensured

Thus the Afssaps deems that “exposure to antiperspirant products with concentrations of 20% aluminium chlorohydrate does not ensure consumer safety under normal conditions of use.

In conclusion, the Afssaps recommends:

 to restrict the concentration of aluminum in cosmetic products at 0.6%;
 not to use cosmetics containing aluminum on damaged skin (after shaving or if the consumer’s skin is affected by small cuts), and to clearly indicate this information on the packaging.

Concerning cosmetics others than antiperspirants, the Afssaps underlines that regulations could become more stringent, as its risk assessment does not take into account the total exposure to various products likely to contain aluminium.