|
 It is no secret that cosmetics with sun protection factor should be used not only during the holidays, while in the southern latitudes, but in everyday life, because ultraviolet light does not sleep! But as a rule, on protective creams, sprays and the like remembered during the holiday season. Sunscreens are quite varied in composition, and the degree of protection against radiation, but one goal - to prevent the negative effects of sunlight.
Choice of protection against the sun
So, in sun cosmetics used chemical, physical filters and their various combinations created to enhance the effect of UV protection.
Chemical filters are able to absorb
solar radiation due to its chemical structure, and by using modern compounds as UV filters is absorbed types A and B.
Physical filters reflect and scatter
radiation. In the application and that, and another group of sunscreen has its own quirks that cause and price of cosmetics and their effectiveness.
Sunscreens are designed (scary thought!) Since 1891. The first filter was, of course, mineral filters. Since that time, since sunscreen formulations made perfect. Modern facilities - complex multicomponent systems comprising not only the combined filters, and various additives that enhance the protective effect.
Physical filters
Today, the most widely used two physical filters -
titanium dioxide and zinc oxide
. Most importantly in manufacturing technology - that the particles of these materials must be strictly defined size, or protective properties may change. For example, an increase in particle size is shown on the skin "effect of white," that is unevenly distributed over the tool skin, resulting tan turns "stripes."
More improvements compositions with mineral particles on the filter materials special coatings applied to separate them, and did not change the properties of the sun. To extend the range of the reflected light, a combination of titanium dioxide and zinc oxide, as a first active against UV B, and the second - against ultraviolet A. Zinc oxide is more transparent. Sometimes, rarely, using another substance -
iron oxide
. It has a brick color, so is used in low concentrations.
Chemical filters
Chemical filters a lot. But all of them can be divided into several large groups, so to speak, "the chemical origins."
1. A cinnamic acid or cinnamates.
They are active against ultraviolet B. The best-known and common in the composition of domestic and foreign cosmetics - octocrylene and EMC (ethylhexyl methoxycinnamate). Please note that the major foreign manufacturers prefer not to specify a part of the chemical and trade name sunscreens, for example, Parsol or Nelitopan.
2. The derivatives of salicylic acid or salicylates
For example, octyl salicylate, avobenzone. Some members of this group are active against ultraviolet A, some - against ultraviolet B.
3. Benzophenones
- The most advanced solar filters, as they provide protection against all types of ultraviolet radiation.
The principle of operation of chemical filters other than the physical. They penetrate the skin, their molecules are aligned in a certain way and there occurs absorption of harmful rays.
For the composition of a sunscreen is important as the content of the additional components that provide resistance to the skin free radicals or prevent this process.
Antioxidants
Added to the means of sun protection: ascorbic acid (vitamin C), tocopherol (vitamin E), coenzyme Q, extracts of calendula, pine, spruce, fir, larch. These extracts not only contain natural antioxidants composition, but also possess self light absorption.
What does the SPF?
The degree of protection of the skin with the help of a cosmetic product depends on the protective factor SPF (a number indicating how many times the sun exposure is reduced when using this tool) - the higher it is, the greater the protective ability of the drug.
For the calculation of safe sun exposure time necessary to multiply the SPF number on the time in the sun to burn for your skin type.
The labels of sunscreen you can find four groups of SPF of the degree of protection: Low (SPF 2-5), medium (SPF 6-11), high (SPF 12-19) and very high (SPF 20 or more).
As a rule, a low degree of protection now everyone has a daily cream and higher - sunscreen. Solar protection with chemical filter is recommended for people who have no particular problems with the skin. If the baggage a person has dermatological abnormalities such as a tendency to the formation of age spots, it is recommended to use only physical filters. For children also use sunscreens that shield the skin rather than absorb radiation.
Doctors recommend a daily basis to protect the skin from harmful solar radiation, because it is the active prevention of skin aging. Using creams with protective filters to avoid the unpleasant effects of sunburn. This is especially important for people with light skin, children and people with luggage in his skin disease.
Tips for using sunscreens for vacationers:
-
with strong insolation, especially if you have fair skin, you should wear light natural fabrics, well covering the body. Such clothing will allow your skin to "rest" after an active sun on the beach;
-
on vacation nice hat with a wide brim;
-
sunscreen should be applied 30 minutes before going out, again - after swimming;
-
it is not recommended to use any sunscreen for infants six months of life. To protect them make better use of natural light clothing;
-
do not forget sunglasses - UV adversely affects the cornea;
-
Some drugs may provoke photoallergy example, many antibiotki, contraceptives;
-
such surfaces as cement and sand reflect UV light, that is, you will get higher doses;
-
Remember that the risk factors for the negative effect of ultraviolet radiation are: white skin, blond hair, a tendency to the formation of freckles, the trend burns easily, skin diseases in the family, a long stay in the sun for the whole of your life, burning up "bubbles" in childhood or adolescence ;
-
it is best to have a means to protect a variety of factors, including water-resistant (especially true for children);
-
photoprotective cream shelf life - six months from the start of use. If the cream changes the smell, texture or color, it can not be used;
-
with oily skin need to use sunscreens labeled oil-free - without oil;
-
the skin on his face is much more delicate, so the protection factor creams for the face to be higher than for the body.
|
|
|
|
|
|
