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Although sun protection cosmetics are taking up more and more space on store shelves, it is not easy to protect yourself from the harmful rays of the sun. A cosmetic with an SPF 50 filter protects almost the same as that with an SPF 30. However, regardless of the value of the filter, an improperly applied preparation does not guarantee any protection.
When buying preparations to protect against the harmful effects of the sun, we used to pay attention only to the value of the SPF filter on the packaging, which informs about the degree of protection against UVB rays. The higher it is, the safer we feel in the sun. It turns out, however, that high SPF is not enough. Safety is also not guaranteed by frequent – even as recommended every three hours – lubrication with the preparation. A good cosmetic must contain information that it also protects against UVA rays. The method of applying the preparation to the skin is also important.
Sunlight
Although the sun is essential for life, it can be dangerous, especially the UVB and UVA radiation it emits. Until recently, it was believed that only UVB radiation was dangerous. Although it does not penetrate deeply into the skin, it is responsible for the appearance of erythema and sunburn, and also tans the skin. This radiation is filtered by clouds and window or car windows, which means that on cloudy days and when we are indoors or in a car, we receive a smaller dose of it. Today we know that UVA radiation is also dangerous, as it penetrates the skin very deeply, down to the level of the dermis. It does not cause erythema and burns, but like UVB, it is responsible for the so-called photoaging and neoplastic skin changes. Clouds, windows and car windows only partially stop them. It is this type of radiation that is used in tanning salons. That is why, for example, in Germany, there is a statutory ban on the use of tanning beds by people under the age of 18.
Cosmetics with a UV filter
How to protect yourself from harmful radiation? You have to use cosmetics with filters. It turns out, however, that their type and quality are of great importance. A good sunscreen cosmetic must be safe and effective.
Two types of substances are used in cosmetic preparations that are supposed to protect us from solar radiation. Some – they absorb radiation, the other – reflect it. Unfortunately, none of them are perfect.
– Some ingredients used in the production of filters that absorb UV radiation penetrate the skin and therefore are subjected to very careful toxicological tests. Due to their widespread use, this raises some concern among toxicologists. So far, no harmful effect has been found in their case. However, some older generation filters under the influence of UV radiation undergo chemical changes on the skin – says Prof. Jacek Arct rector of the Academy of Cosmetics and Health Care in Warsaw. Therefore, the latest generation of ray-absorbing filters uses ultraviolet-resistant substances whose particles are too large to penetrate the skin.
Titanium dioxide in cosmetics
The second type of sunscreen is sun-reflecting substances. For this purpose, powdered titanium dioxide (TiO2). It has been proven that it does not penetrate the skin, despite a tendency to accumulate in the hair follicles. – However, such a high fragmentation of each substance can change its properties. For example, a silver ring does not have a disinfecting effect, but shredded silver in the form of a colloidal suspension – yes. The fragmented substances can therefore become chemically active and react with, for example, other ingredients of cosmetics. Therefore, the fragmented particles of titanium dioxide began to be covered with inert substances – explains Prof. Arct. – It is a very expensive and not always fully effective process. There are also no standards defining the parameters of substances protecting against UV radiation or titanium dioxide protected in this way – he emphasizes.
Safe protection from the sun
– Only the use of several filters in one cosmetic, both those absorbing radiation and reflecting, gives the skin adequate protection – explains Prof. Arct. – In addition, it must be remembered that human skin, even in an infant, is not smooth, there are microscopic folds in it. Meanwhile, every corner of the skin needs to be covered with a protective cosmetic that absorbs or reflects rays. Only then can we obtain adequate protection. – Therefore, the preparation must not be spared. You also have to smear it long and carefully, 15 circular movements with your finger to the right and 15 to the left – he adds.
Filtr SPF
So far, no scale has yet been developed in which the effectiveness of the protective effect of the preparation against UVB and UVA radiation can be measured in the same way. The packages of sun protection cosmetics contain SPF values, commonly known as a filter or factor.
– SPF (Sun Protection Factor) applies only to UVB radiation and it is a measure of protection against sun irritation. Interestingly, the intensity of the actual protection does not increase proportionally to the increase in the SPF value. The difference in the degree of protection between SPF 2 and 6 is three times greater, but the difference between SPF 15 and 30 is insignificant. In practice, this means that regardless of whether we use a cosmetic with SPF 30 or 50, our skin will be protected in almost the same way, explains Prof. Arct. Therefore, in the USA, the display of SPF values was limited to 30, and in Europe to 50. SPF 100 was just an advertising slogan that misled the consumer.
An effective cosmetic, in addition to the specified SPF value, must also contain information that it protects against UVA. Therefore, you should only use cosmetics with a clear imprint on the packaging that protect against UVA and UVB radiation.
Text: Halina Pilonis