In cosmetic formulations PEG (polyethylene glycols) and specifically their derivatives, the ethoxilized alcohols are frequently used as surface active agents. They serve as solvents, emulsifiers, tensides and re-fattening agents in skin care as well as in cleansing products. Among their advantages are their low manufacturing costs on the one hand and on the other hand the possibility of formulating them synthetically as required in the specific product.
Their disadvantage is that they are not physiological which means that they are not biodegraded in the skin and, depending on their structure they consequently lead to a more or less intense washing out effect of the natural protective substances of the skin during skin cleansing. A further disadvantage is that they are quite sensitive to the joint attack of atmospheric oxygen and UV radiation (sun light). During this process highly reactive peroxides are formed which can trigger "Mallorca Acne" in sensitive individuals. In order to prevent this effect, there are frequently antioxidants added to the formulations which again are controversial substances regarding their allergenic potential.
Dr. Hans Lautenschläger