Sunscreen is a cosmetic that protects the skin from the negative effects of UV rays. If well-fitted, it will effectively protect against both sunburn and premature aging of the skin. What should I consider when choosing a sunscreen?
Types of solar radiation
It is worth realizing that sunlight reaches the earth all year round, with different intensity. UVC radiation is completely absorbed by the earth’s atmosphere. UVB beams are partially trapped in the ozone layer, which transmits about 3% of the UVB radiation reaching the earth’s surface. As a result, up to 97% of UVA radiation reaches our planet. This is what you need to protect your skin from.
When to use sunscreen?
Our skin is not only exposed to ultraviolet rays generated by the sun. It needs full protection all year round in the form of a sunscreen. Some surfaces are not able to absorb 100% of the sun’s radiation. Instead, they reflect it. Snow falls into this category. It is white, so it absorbs light beams only slightly. Snow reflects about 95% of ultraviolet rays, sand reflects 25%, and grass reflects 5%. A well-fitting sunscreen reflects the UVA and UVB rays that irritate our skin. Products containing titanium dioxide or zinc oxide in their composition cope with this task best. A separate category of products are chemical sunscreens. In their case the protection is that the sun’s rays are not only absorbed but also converted into heat. On store shelves you can find sunscreens that are a combination of mineral and chemical creams. If you have sensitive or vascular skin, you should refrain from using chemical sunscreens. This is due to the fact that products of this type may have irritating properties. A much better solution in this case will be mineral creams containing substances with moisturizing properties.
SPF – what is it?
SPF (Sun Protection Factor) refers to the numerical value of a sunscreen’s ability to protect against harmful UV rays. It tells you how many times longer your skin can be exposed to the sun without fear of burning. Lack of effective sunscreens can result in sunburn after only about 20 minutes. An SPF 15 sunscreen can effectively extend the time of safe sun exposure by 15 times, an SPF 30 by 30 times and an SPF 50 by 50 times. For these creams to be effective, you need to apply the right amount and remember to apply them regularly every 2-3 hours. This is due to the fact that contact with water or physical exertion causes abrasion of physical filters and oxidation of chemical ones. Importantly, SPF refers to the degree of protection against UVB radiation. Consequently – even a very high sunscreen may not be able to effectively protect against UVA rays.
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