In order to achieve a factor of 60, 80 or even 100 and to be allowed to call themselves sun blockers, the most different sun protection factors are mixed with substances like skin-irritating emulsifiers on the basis of polyethylene glycol (PEG), stabilizers, silicone oils, preservatives and antimicrobial components, antioxidants, thickeners and perfumes. Advertisements then promise natural, sporty tans. But certain protective substances, such as benzophenones, ethylhexyl methoxycinnamates, butyl methoxydibezoyl methanes and 4-methylbenzylidene camphor, which affects the hormonal system, are themselves a danger to the skin. Important for the actual sun protection effect are the filter substances, also called UV absorbers. The level of protection of sun care products is expressed in the sun protection factor. The skin has a certain, individually very different self-protection against the sun before it becomes red and inflamed. On average, 20 minutes is assumed for untanned skin. The sun protection factor now indicates how much longer you can expose yourself to the sun with sun protection. So sun protection factor 12 means 12 times 20 minutes or 240 minutes = 4 hours. High protection factors are in. They suggest safety. But how does it look in reality? Cosmetic experts say: Anything above factor 20 hardly makes any difference to the protective effect and only makes sense in the case of extreme exposure such as high mountain hiking. The Swiss Cancer League points out that with a factor of 15, ninety percent of UV-B rays are already filtered out and that with higher protection factors, the filtering effect increases very slightly, but under certain circumstances the strain on the skin becomes higher. Sun protection products with factor 20 are also available without chemical UV filters A basic distinction is made between physical and chemical UV filters. Mineral filters do not penetrate the skin but reflect the light on the skin surface. In the market-leading sunscreens, physical-mineral filters are usually combined with chemical UV filters. These penetrate the skin and convert it into the less problematic thermal radiation. Most of these chemical components are considered allergenic. Almost all chemical filters are suspected of having a cell-damaging effect. The chemical light protection substances are frequently involved in undesirable skin reactions. They have a strong allergenic potential or may lead to phototoxic reactions. Due to the run on high protection factors it has been completely forgotten that filters are not only a protection but also a strain for the skin.

Sun protection filters, sun protection products, a summary name for cosmetic materials with very different chemical combinations which have an effect of reducing on sun rays (UV light) on the skin in specific areas. The short-frequency UV rays (UV-B) are absorbed (taken up) and the longer-frequency rays (UV-A), which are responsible for skin browning (pigment construction) for natural own protection, are let through or can be held back by sun blockers. Small amounts of sun protection filters which are distributed in a very thin layer on the skin must allow an optimal effectiveness to unfold. They must neither be changed nor destroyed by the light, and must be very well-tolerated by the skin, because very large surfaces are involved. Also, they should be as scentless as possible.

Our investigations have shown that several commonly used UV filters have hormonal activity. 8 of 9 UV filters tested were estrogenically active and 2 of 8 were antiandrogenically active. The potency of the UV filters is in the range of that of other estrogenic or antiandrogenic environmental chemicals. If the toxicology of these UV filters is addressed, the various routes of exposure must also be discussed. We are exposed to UV filters through sunscreen and through many cosmetics. However, with increasing use in cosmetics (increase in sun protection factors,use as product protection), the release of these substances into the environment and thus exposure via the food chain (fish, human milk) must also be considered. The hormone-active UV filters become components of the complex mixture of hormone-active environmental chemicals, the overall effect of which cannot yet be assessed at the present state of knowledge. Estrogenic (female hormonal activities) and antiandrogenic (male hormonal activities) UV filters have been found in: Benzophenone-1, Benzophenone-2, Benzophenone-3, Benzophenone-4, t-Butyl-methoxydibentoylmethane (BMDM), Homosalate (HMS), 4-Methylbenzylidenecamphor (3-BC), Ethylhexyl-dimethylPABA, Octyl-dimethyl-PABA, Ethylhexyl-methoxycinnamate, Octylmethoxycinnamate (OMC).