We are so used to applying a cream or a shampoo that we often don’t pay attention to the gestures or to the products we are actually putting on the skin or scalp, looking only at what the advertising of that cosmetic promises. Luminous and young skin, shiny and silky hair! How many times we have read these phrases on the packaging of a product, but here you go punctually rashes, itching, pimples, the skin becomes dehydrated and the hair is oily. Often are the products that we use that, due to some ingredients they contain, can be comedogenic or irritating. In the previous post we introduced preservatives, we continue to describe this class of substances.
Every cosmetic product that contains water must also contain preservatives with bactericidal and anti-mold action to avoid any consequences on the skin such as irritations or allergies. In the previous post we saw two substances widely used in conventional cosmetics, denatured ethyl alcohol and phenoxyethanol, today we will see the parabens, EDTA and quaternium. The parabens, substances derived from the condensation of an acid with an alcohol, have a broad spectrum of action against bacteria, yeasts and fungi, are easy to produce, cheap and therefore used in cosmetics. But they also have effects on the human body that are not yet well understood, according to several scientific studies. What is clear, is that the parabens, after topical applications of cosmetics, overcome the skin barrier and reach the tissues (Kirchhoff et al, Skin Therapy Lett, 2013). This is a fact that makes think. Moreover, it has also been observed that parabens are present in the tissues affected by breast cancer (Darbre et al, J Appl Toxicol, 2004 and 2008). To this day, it is not possible to determine whether or not there is a connection between these substances and tumors but the parabens are classified by the European Union as endocrine disruptors and this means that they can potentially interfere with the body's hormone production. Many companies have started producing products without parabens and the advice is, in general and where possible, to avoid these substances. The names with which the parabens appear in INCI are Methylparaben, Ethylparaben, Propylparaben, Butylparaben and Isopropylparaben. Also the European Union has begun to move against parabens by prohibiting the use in products destined to children and by restricting the usage in the other products of some parabens like Propylparaben and butylparaben. And the EDTA? It is ethylenediaminetetraacetic acid, with antibacterial power, able to hold the molecules of heavy metals but also, unfortunately, very polluting, since it reaches the aquifer and hence fish, and results toxic by inhalation. It appears in the INCI with a name followed by EDTA and therefore, where possible, it would be better to avoid it. In eco-friendly products this substance is replaced by other safer substances such as citric acid. And finally the quaternium, which in the INCI appears with the name Quaternium-15, Quaternium-18, Polyquaternium-10, Diazolidinyl Urea, Methylisothiazolinone. The problem with this class of substances is that they can release formaldehyde, which is a strong allergen and has also a carcinogenic effect.