No half measures

Dermatologists in Central Europe distinguish four tanning types: type I with a self-protection time of 10 to 15 minutes, type II about 20 minutes, type III about 30 minutes, and type IV 45 to 60 minutes. If the capacity of the endogenous protection system is exceeded, the UV rays will cause damage to the skin. UV-B rays can cause sunburn and can change the cell nuclei of the skin cells in such a way that skin cancer will eventually develop. UV-A rays penetrate deep into the skin. They damage the connective tissue fibres thereby reducing the elasticity of the skin. The threshold for such effects is significantly lower than that for sunburn. The effect of UV-A rays is not immediately visible but has an impact at a much later date. The skin ages quicker. Moreover, the UV-A rays induce pigment production, which leads to the so-called aging spots. UV-A rays can ultimately contribute to skin cancer. On the whole, UV-A rays increase the risk of skin cancer less than UV-B rays do.

Sunscreen products are to provide protection from UV-A and UV-B rays. There are numerous preparations in the form of lotion, spray, cream, oil, stick or foam on the market. Their effect is based on substances which keep the sun’s UV rays away from the skin. Currently there are 27 chemical or mineral UV filters approved in the European Union. Chemical filters are organic molecules which absorb the sun rays and transform the short-wave, high-energy UV radiation into long-wave, low-energy radiation. Physical filters work with the help of mineral pigments such as titanium dioxide and zinc oxide, which weaken UV rays by means of dispersion and reflexion. Pigments do not penetrate the skin and are therefore well tolerated. The fact that they often leave a whitish film on the skin is a disadvantage.

Normally, the individual substances do not provide any protection across the entire UV spectrum. Therefore several substances are used in one preparation. Products that show a defined protection from UV-A rays may be marked by the »UV-A seal« within the EU.

The sun protection factor (SPF) is a reference value for the protection from UV-B rays provided by a sun protection preparation. It corresponds to the factor by which the self-protection time of untanned skin, after having applied the preparation, is multiplied. As SPF values are determined in a laboratory where test conditions do not quite correspond to the reality, experts recommend reducing the calculated period of time by 30 percent to be on the safe side.

According to the current EU guideline, there are four sun protection factor classes: Basic (SPF 6 and 10), medium (SPF 15, 20 and 25), high (SPF 30 and 50) as well as very high (SPF 50+).

Apart from the skin type, radiation intensity also plays a role when choosing a suitable product. Radiation intensity is, for example, considerably stronger in high mountain regions or by the sea than somewhere in central Germany. Other relevant factors for the intensity of sunlight are the time of day and year, cloudiness and the proximity to the equator. The stronger the radiation intensity the higher should be the chosen SPF.

Children have to be particularly well protected as their self-protective mechanisms are not fully developed yet. Preferably, Babys and infants should not be exposed to direct sunlight at all. Elderly people too are more sensitive to UV radiation and therefore need stronger protection. With increasing age, the effectiveness of cellular repair systems decreases.

It is important to apply sun protection preparations 20 to 30 minutes before sunbathing as it takes some time for the protection to be effective. With some products the producers state that they are effective immediately. By means of special galenics, the substances can be spread more easily on the skin and immediately form a cohesive film.

»The more the better«. Most consumers do not know that. They apply the product sparingly and are therefore not optimally protected. It is important to re-apply the preparation after some time to maintain the sun protection. The protection should be renewed every two hours at the latest or after each bath and drying oneself. Re-creaming will make up for losses but does not extend the total duration one should stay in the sun. Preparations may be designated »waterproof« if they still provide at least half of the original protection after having water contact twice of 20 minutes’ duration each.