Tanning is a natural reaction of the skin which is a defense against the aggression's of the sun. When we expose ourselves to the sun, the melanin in the basal layer back toward the layer closest to the skin's visible surface. In the course of this displacement, the melanin oxidizes and takes on a dark color, and produces the effect that we all know with the name of tanning.
The tan fencing sunlight and protects the skin, but that does not mean we can stay in the sun for unlimited times and especially without the proper protective factor because the effects can be very harmful.
Solar rays: UVA, UVB, UVC
The sun emits electromagnetic radiation at different wavelengths with different effects on the skin:
- UVA rays penetrate deep into the dermis. They are responsible for aging and phenomena phototoxicity and photoallergy.
- UVB rays cause the most common biological photos reactions in the skin, erythema action and they are almost totally absorbed by the surface layer of the skin. They are critical for the synthesis of vitamin D.
- UVC rays do not have action on the skin because they are blocked by the ozone.
To benefit from the positive effects of the sun, it is therefore essential to prepare adequately for sun exposure by choosing the appropriate protective factor.
Sun protection factor: use the right cream!
The sun protection factor (SPF: Sun Protection Factor) is a numerical value (from 6 to 50+) that indicates the product's ability to screen the sun's rays. The numerical value of the SPF is the ratio between the time necessary to produce the onset of erythema on the skin protected by the sunscreen product (protected skin MED) and the time required to produce the same response without protection (MED unprotected skin) . SPF: MED (protected skin) / MED (unprotected skin) The SPF allows you to choose a suitable protection to your skin type and sun exposure conditions.
The categories of sunscreens on the market, depending on their degree of protection are:
<6: it can not be considered a barrier cream
6-10: Low
15-20: media
30-50: High
50+: Very high
Once you find your skin type (skin type), applied regularly photoprotector suitable.
It 's very important to remember that the purpose of these products is not to increase the number of hours of exposure but to reduce the risks during exposure.
