Sun Protection

The simplest form of protection against the sun is to wear clothing, including a hat. However, thin cotton fabrics only provide limited protection against sunlight. They have a sun protection factor (SPF) of 10 for UVB radiation. A wet cotton T-shirt still allows about 20 % of UV radiation to pass, so has an SPF of 5. Therefore, even when wearing clothing, it is still recommended also to apply a waterproof sunscreen. Because of this only limited level of protection provided by thin textiles, in countries with high sunlight intensity such as Australia working clothes and also children’s clothes are now being produced with higher sun protection factors. Some textiles with a high sun protection factor for children are also available in Germany.

There is a wide range of sunscreen products that differ in the type of filter they use, e.g. against UVA radiation only or against UVA and UVB together (broad-band filter). But they also differ in the type of product base used, ranging from oils, oil-in-water and water-in-oil emulsions, to pastes, hydrogels, hydrodispersion gels, lipogels and liposome products. All of these types have advantages and disadvantages. In the case of emulsions, which are mixtures of oil in water, the effectiveness increases in line with the water content, as the carrier substance is better able to penetrate through the horny layer of the skin. Pastes, if appropriately made up, provide complete sun protection even without a chemical sunscreen, as their basic ingredients – especially titanium dioxide and zinc oxide – cause the sunlight to be completely reflected. However, they enjoy little acceptability from a cosmetic point of view. Hydrogels are especially suited for sufferers of Mallorca acne as they do not contain any emulsifiers or triglycerides. However, they cause severe drying of the skin and leave the skin feeling tight. An improvement on hydrogels are hydrodispersion gels, as they contain grease components such as silicon oils, are water-repellent and return the oils to the skin. Since they also contain no emulsifiers or triglycerides, they can likewise be used by people with Mallorca acne. Oils and lipogels have the disadvantage that because they contain no water, only low sun protection factors can be worked into them. Additionally, they are only suitable for very dry skins. An interesting new development are liposome products in which the sun protection filter is incorporated into liposomes. These are able to enter the cell membranes of the horny layer of the epidermis, and they also guarantee relative water resistance.

Sunscreens

Sunscreens extend the auto-protection time of the skin. A distinction is made between physical and chemical sunscreens. Physical sunscreens include micropigments, which mainly function by reflecting the incoming light, and only to a lesser extent by absorbing it. In some tropical countries, physical sunscreens have been in use for centuries. Examples of these are the sandalwood pastes that are traditionally used in Burma on the face and arms or the pigment pastes used by African tribes. Modern sunscreens mostly contain one of two substances, namely titanium dioxide and zinc oxide. The first products with these micropigments had the disadvantage of colouring the skin white and, as thick pastes, being difficult to spread. For skiers, pastes are now available that provide complete cover and have brightly coloured additives. There are also some lipsalves of this type on the market. Today, products are available in which the micropigment particles are so minute in size that the white colouring is almost invisible.

Chemical sunscreens

Sunscreens initially contained only UVB filters, but today most of them are combination products to protect against both UVA and UVB radiation (broad-band filters). The sunscreening substances fall into two categories: absorbent ones (UV filters) and reflecting ones (pigments). Commonly used UVA filters are benzophenone and dibenzoyl methane. UVB filters consist of benzimidazole, homo-salicylates, camphor derivatives, para-amino benzoic acid and its derivatives, and cinnamates. As reflecting substances (pigments), primarily titanium oxide, zinc oxide, iron oxide, kaolin and talcum are used.

Care after sunbathing

In addition to UVA and UVB radiation, the skin is also exposed to infra-red radiation when sunbathing. The infra-red rays heat up the skin. The skin responds by producing more sweat in order to cool the body by evaporation. This constant loss of water through sweating dries the skin out. Consequently, the skin feels tight after lengthy sunbathing, even if no sunburn has occurred. It is best to take a short shower to remove sweat and the remains of the sunscreen and then apply a remoisturising body lotion. Moisturising creams may contain urea or glycerine. After-sun products also contain small quantities of gentle anti-inflammatories such as panthenol, bisabolol or allantoin. Hamamelis extracts, which have a mildly antibacterial and numbing effect, can lessen the results of slight sunburn. Patients with Mallorca acne should use after-sun products such as hydrogels and hydrodispersion gels that are free of emulsifiers and triglycerides.