Militares de Suiza

Composition of the solar products

An effective protection must block as well the rays UVA as of the rays UVB: the UVB (and to a lesser extent UVA) can cause the sunstroke, the UVA cause a premature ageing of the skin, the UVA and especially the UVB cause Cancer S of the skin.

A solar product is composed of ultraviolet filters in a base which can be a Huile or more frequently a emulsion (cream or lotion). A aqueous emulsion makes it possible to apply a greater thickness of product to the Peau and is not Gras with the Toucher.

The sun lotion generally contains other ingredients: preserving S, agents for to stabilize the emulsion, free anti-radicals (Vitamin E or Vitamin C for example), thickener S, agents hydrating… The formulation holds account owing to the fact that the product must adhere to the Peau, and to resist the Eau.

Ultraviolet filters

There exist two types of ultraviolet filters:

the chemical filters , organic chemical compounds which absorb the ultraviolet light (like the Oxybenzone)
the mineral filters, of the opaque materials which reflect the Lumière (like the Oxyde of zinc or the Dioxyde of titanium)

detailed article: ultraviolet Filter

The majority of the solar products contain chemical filters or mineral filters or both.

Use of the solar products

The majority of the people apply the sun lotion only when they practice external activities estival. One recommends the application of the cream or oil 20 minutes before the exposure to the sun, and to renew the application. However, some experts suggest using it the every day to prevent cumulative damage and to lower the risk of Cancer of the Peau. From a point of view of prevention of the Wrinkle S, the manufacturers market creams of day and make-up foundations containing filters UV, for a daily use. One also finds sticks with lips and products capillary providing a protection against the ultra-violets.

To obtain protection corresponding to the Index of protection of the solar product, 2 would have to be applied Mg of sun lotion per cm ² of skin. In this case, one would apply to the body the quarter of a tube of 125 ml to each exposure. In reality, the quantity of sun lotion employed is closer to a Mg per cm ² of skin.

The Sand, the friction of the Towel S and the Eau remove part of the cream on the skin and thus decrease solar protection. Moreover, certain filters are degraded by the rays Ultraviolet S. Therefore one advises to renew the application of cream regularly.

Index of protection

The index of protection (IP) of a sun cream is a measurement of its effectiveness. The index of protection considers the capacity protective of a product against the sunstrokes. It thus relates to anti-UVB protection. The IP is sometimes noted FPS (factor of solar protection) or SPF (sunburn protection Factor).

The index of protection to the same significance in all the Country. It is determined by Test S ized Standard. During these tests, one applies a solar amount of product of 2 Mg per cm ² to part of the Dos of volunteers who are then subjected to various amounts of UV. 24 hours afterwards, one compares the reactions of the skin with and without solar protection. One from of deduced the Amount Erythémale Minimale (DEM), which is most low dose of ultra-violet causing a Rougeur skin. The index of protection is the relationship between the DEM on a zone of skin covered with sun lotion and the DEM on a not protected zone.

The index of protection is also the relationship between the time necessary to obtain a sunstroke with and without the sun lotion. Example, if a person has a sunstroke at the end of 10 minutes without protection, a IP 15 means that it will need 2:30 (that is to say 150 minutes or 15 times 10 minutes) to obtain the same sunstroke with this solar product. Thus more the index is high, better is protection. But one should not lose sight of the fact that all the people are not equal taking into consideration risk, it exists six Phototype S. the clear skins need a protection more raised against UV than the matt skins.

It should be known that protection against UV is not proportional to the value of the IP:
A IP 2 stops 50% of UVB
A IP 15 stops 93% of the UVB (it lets spend 1/15 is 7% of the UVB)
A IP 20 stops 95% of UVB
A IP 30 stops 97% of UVB
A IP 50 stops 98% of UVB

The index of protection IP does not provide any information on protection against UVA. Indeed, the latter cause sunstrokes only for very strong amounts. However, they involve more long-term damage that the UVB. There does not exist an indication of protection against the UVA which is officially recognized. Certain creams give an index UVA nevertheless, but the methods used being different, it does not make it possible to carry out comparisons between different marks.

The index of protection makes it possible to the consumer to choose an adapted solar product. Certain products do not have IP or a IP of 0, they thus do not protect from the sun. It is the case of the autobronzants, the traditional Monoï and “bronzing” oils.

Regulation of the solar products

In Europe and with the Japan, the solar products are regarded as Cosmétique S, whereas in Australia, with the Canada and the the United States they are classified like Médicament S.

The term “ total screen ” is interdict for the sun lotions, because no sun lotion, even with high index of protection, can block 100% of UV.

Are the sun lotions effective?

The sun lotions protect from the UVB and start to also filter UVA. But they have an perverse effect: the people who use sun lotions believe protected from the sun and tend to expose themselves longer to the sun. In the same way, the sun lotions are not intended to the babies, who should not be exposed with the sun.

The solar products are useful but must be associated with safety measures: the wearing of clothing, hat and sunglasses, the not-exposure to the sun between 12:00 and 16:00 (because radiation UVB is with its maximum of intensity) and the time limit of the exposure.

Appendices

Ultraviolet Bronzing
ultraviolet Filter
Phototype

External bonds

How to choose its sun lotion the Solar Safety
Attention: malicious sun!
Recommendations concerning the conditions of labelling of the products of solar protection, Arranges French drug (AFSSAPS), January 2006.

Simple: Sunscreen

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