Staying sun safe

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What is sun's radiation?

Sun's radiation refers to all the electromagnetic waves produced by the sun. These include various types of rays (UV-A, UV-B and UV-C). UV-C rays are fully filtered by the atmosphere and do not reach the surface of the earth. Rays are categorized based on the quantity of energy provided and their skin penetration power:

- x UV-A: They amount for almost 95% of the UV rays reaching the surface of the earth. They can penetrate the deeper skin layers (dermis) and are responsible for the immediate tan effect. They also promote skin ageing and the formation of wrinkles.

- x UV-B: These rays do not penetrate beyond the superficial layers of the skin (epidermis). They are responsible for tanning and delayed sunburns, but also promote skin ageing and the development of skin cancers. 

Which surfaces reflect the most sun's radiation?

Sun's radiation is mostly reflected by:

  • snow (70 to 80%);
  • white surfaces (walls or floors): 20 to 40%);
  • sand (15 to 20%).

And more moderately by:

  • water (5 to 10%),
  • dark floors (3% on grass)

Which are the conditions of athletes' exposure?

1 - Extreme conditions: sun and snow at altitude, sun in the Tropics;

2 - Significant conditions: Mediterranean sun, immobility;

3 - Moderate conditions: temperate countries, sport activities;

4 - Low conditions: daylight without direct sunlight.

The sun is only beneficial in moderation

Sun exposure induces vitamin D synthesis by the skin, sun's radiation influences the immune system and has beneficial therapeutic effects on bone building, vitality and mood. However, too high amounts of sun rays may also cause erythema (or sunburn) due to UV-B at 85% and UV-A at 15%. Tanning is a natural protection against UV rays, but depending on your skin type, this protection may not be sufficient. UV-A and UV-B rays then damage the DNA in the cells of the skin dermis and epidermis, which may result in cancer development. Also, children are less able to be naturally protected from the sun . In the long term skin ageing is accelerated by sun exposure, producing typical wrinkles (heliodermy).

Natural photoprotection

There are 6 skin phototypes, based on skin colours. Each phototype provides more or less natural protection against sunrays. The whiter the skin, the less it is naturally protected against the sun.

Legal context in France

For "sun protection" garments, a European standard (NF 13758-1 et -2) has set up design and communication requirements for industrials.

For products sold to children and adults, the UPF (Ultraviolet Protection Factor) to be used when developing a material must be over 40. Moreover, these products must cover the shoulders with 3/4 length sleeves.

A UPF 40+ T-shirt (youngster and adult sizes) lets through 5% of UV-A rays and 3% of UV-B rays. For UPF 50+ (baby sizes), the material lets through 5% of UV-A rays a,d 2% of UV-B rays.

A label should be attached to the garment to explain the dangers of the sun and specify that "only the covered body parts are protected", and that "the protection provided by this item may decrease if it is stretched, worn out or wet", that "uncovered parts must be protected with sun cream", and that" even with a protection, sun exposure between 11am and 4pm, as well as prolonged exposure, should be avoided".

Significant legal differences per geographical area

  • The sun spectrum is not the same for Australian standards than for other standards (American, French, Chinese): the testing methods are therefore different.
  • Communication varies: for example, sun protection is claimed as from UPF 15 in the United States and Australia, but only as from UPF 40+ in Europe and China.
  • The skin coverage rate concerns only European and Chinese standards. There is no skin coverage rate required in the American and Australian standards (only on material for the latter). Therefore, certain products such as tank tops or swimsuits can be sold with a sun protection claim in certain geographical areas.

Decathlon chose to follow the requirements of the European standard applicable to design and communication in all custom zones.

Stéphanie Mouragues
Product manager
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