Preservatives for cosmetics - Anti-oxidants and anti-UV

A major asset to the French economy, the cosmetics industry is a very active market, representing average sales of 16 billion euros a year.

With an average expenditure of 205.45 euros per year per inhabitant (in 2009) on hygiene, perfumery and beauty products, the French are the 4th biggest consumers of cosmetics in the world, behind the United States, Japan and Brazil.

Within this lucrative market, organic and natural cosmetics are steadily expanding, in response to growing consumer demand.

A cosmetic product is defined as "any substance or preparation intended to be placed in contact with the various superficial parts of the human body or with the teeth and oral mucous membranes with a view, exclusively or mainly, to cleaning them, perfuming them, modifying their appearance and/or correcting body odors and/or protecting them or maintaining them in good condition".

Whatever the nature of the cosmetic product, it must offer the consumer a certain organoleptic and sensory pleasure, but must also comply with safety conditions so as not to compromise the user's health.

To this end, it is essential to protect cosmetic products from the harmful effects of oxidation by adding antioxidant preservatives and controlling storage and packaging parameters. This ensures that the product lasts a sufficiently long time, and that consumers enjoy optimum use.

Antioxidants used in cosmetics can be of synthetic or natural origin. While the trend is to reject products of synthetic origin, and some results question the safety of synthetic antioxidants such as BHA or BHT, natural antioxidants are at the center of interest and widely studied.

The criteria for choosing one or more antioxidants are complex, since good antioxidant efficiency means protection against oxidation caused by air, but also against photo-induced oxidation, as well as against catalytic factors such as temperature and the presence of metallic traces or certain photosensitizing elements. In addition, the antioxidant agent must not alter the product's odor, appearance or color, nor be toxic or allergenic.

So, in order to propose a formula with optimized antioxidant protection, it is important to understand which factors induce oxidation, which raw materials and which cosmetic products are particularly affected by oxidative degradation, and what the resulting degradation mechanisms are. Understanding these elements then enables us to better define the role that the antioxidant agent should play in the formula, and to choose the most appropriate one, whether synthetic or natural. Other parameters, such as packaging or the addition of raw materials that potentiate the antioxidant...