The summer sun is strong, sun protection tips will help you cope with it easily!

As a reliable senior, Xiaoxi likes summer, of course not because of the beautiful skirts! (Are you sure?) Summer has lush vegetation, abundant rain, and comfortable weather. Summer is beautiful, isn't it? But for women, summer is also a headache, because if you don't pay attention, your skin will get tanned or even sunburned. This column presents you with a summer sun protection strategy, so that you can be white and glowing in the hot summer.

Of course it’s ultraviolet rays, the number one killer that causes skin darkening.

Ultraviolet rays refer to light with a wavelength of 10 to 400nm (nm: nanometer) in sunlight. The red, orange, yellow, green, cyan, blue and purple that we usually call are all visible light, which is the light that our naked eyes can see, while ultraviolet rays are invisible light, which is located outside the purple light in the spectrum and cannot be directly observed by our naked eyes.

Spectrum

According to different wavelengths, ultraviolet rays can generally be divided into UVA , UVB , and UVC .

UVA : wavelength 320-420nm, also known as long-wave ultraviolet rays, accounting for 95%-98% of ultraviolet rays. UVA has strong penetrating power and a long wavelength. It can penetrate the surface of the skin and go deep into the tissue below the dermis, destroying the collagen, elastic fiber tissue and other microstructures inside the skin, causing wrinkles and fine lines, making the skin loose and aging. It can be called a terrible "sun killer".

In the energy distribution of ultraviolet rays, UVA is the main cause of skin tanning. It can reduce the content of hyaluronic acid that binds water in the skin, make the skin dry, accelerate the formation of melanin, darken the skin color, and is also an important cause of skin cancer.

UVB : wavelength 280-320nm, also known as medium-wave ultraviolet rays, accounting for 2%-5% of ultraviolet rays. UVB has weak penetrating power and can be blocked by glass, parasols, and clothing. It can reach (but cannot penetrate) the dermis and cause sunburn, redness, peeling, darkening, etc.

UVC : The wavelength is 100-280nm, also known as short-wave ultraviolet rays. Before reaching the earth, almost all of them are absorbed by the ozone layer in the atmosphere. Therefore, there is no need to consider UVC when sunscreening.

①First , you need a bottle of sunscreen

Currently, the mainstream sunscreens on the market are mainly divided into physical sunscreens and chemical sunscreens. The difference between the two lies mainly in the sun protection principle.

Physical sunscreens achieve sun protection by physically shielding the skin and reflecting ultraviolet rays. The main ingredients are white powders such as zinc oxide and titanium oxide. Physical sunscreens are generally mild and non-irritating, but they are thick (cream-like) and not easy to apply evenly. After application, they feel greasy and the skin becomes noticeably white.

Chemical sunscreens work by reacting with ultraviolet rays, absorbing them, and converting them into heat to achieve the purpose of sun protection. Its ingredients are usually complex, including octinoxate, mesonaline, avobenzone, benzophenone, etc. Chemical sunscreens are generally refreshing and non-greasy, with a light texture (in the form of lotion), easy to apply evenly, and some even have a cooling feeling (probably because of the addition of alcohol), and the skin does not turn white after use.

There is no difference between physical sunscreen and chemical sunscreen, it mainly depends on personal needs and skin tolerance. For example, the ingredients of physical sunscreen are relatively stable and not likely to cause allergies, suitable for children, dry skin, and sensitive skin; chemical sunscreen is more likely to cause allergies, but it is easy to make products with high SPF, waterproof and sweat-proof. So, we just need to choose according to our own situation.

What to look for when choosing sunscreen ?

Look at the bottle! The SPF and PA on the sunscreen bottle are indicators of the sun protection ability.

SPF : SPF stands for protection against UVB. The higher the SPF value, the longer the sun protection time. For example, if the skin of yellow people is exposed to the sun for 15 minutes without protection, it will turn red. If a sunscreen marked as "SPF25" is used, it means that the time can be extended by 25 times, that is, the skin will not turn red until 375 minutes (6.25 hours) (this is just a theoretical time, the skin's ability to withstand ultraviolet rays varies from person to person, time to time, and place to place).

So, is the higher the SPF, the better? Scientific comparisons have found that within the effective time of sunscreen, SPF15, SPF30, and SPF50 sunscreens can block 95%, 99%, and 99.5% of UVB respectively, with no significant difference. Therefore, for daily sun protection, SPF15 is enough, and for outdoor activities, you can choose a sunscreen with a higher SPF.

PA : PA stands for the ability to protect against UVA. PA+, PA++, and PA+++ represent effective, quite effective, and very effective, respectively. The more + signs there are, the stronger the product's ability to prevent sunburn.

However, PA is an evaluation index for Japanese sunscreens to evaluate their UVA protection effect, and it is not an internationally unified certification standard. Some European and American brands often use broad spectrum to indicate that they do not have a PA label, which does not mean they do not protect against UVA.

Here is a special reminder: Europeans and Americans like sunbathing. Some sunscreens have a "tanning" effect, which can ensure that you can get a tanned, chocolate-colored, or bronze skin without getting sunburned. There is a "TAN" logo on the bottle, so friends who want whitening should never choose this...

Using sunscreen is not enough , you have to use it right

1. Apply it half an hour before going out. This is because some ingredients in sunscreen can only play a long-term sun protection effect after penetrating into the surface of the stratum corneum.

2. Shake before use. The active ingredients of sunscreen may be separated into layers when it is left standing. Shaking will make it more evenly distributed. Some sunscreens also have beads in the bottle to make it easier to shake (think of correction fluid...).

3. The technique does not need to be too "particular", just apply it evenly, and there is no need to massage or circle repeatedly. Because sunscreen is different from skin care products such as essence and lotion, the purpose of applying it is not to allow the skin to absorb it, but to cover it.

4. Apply enough to be effective. Generally, you need to ensure that there is 2 mg of sunscreen per square centimeter of skin. A US study found that if you only apply half the amount of SPF50 sunscreen, the sun protection index is only equivalent to SPF7. Taking the face of a normal adult as the standard, it is recommended to apply a one-dollar coin-sized amount of heavy cream sunscreen and two one-dollar coins-sized amount of light emulsion sunscreen.

5. Reapply! Reapply! Applying sunscreen once before going out will not last you all day. Reapply every 2-3 hours when outdoors, and after swimming, toweling, and heavy sweating.

②After using sunscreen , you still need an umbrella

Xiaoxi believes that the ultimate way to avoid getting tanned is to avoid being exposed to the sun! The sun protection guide given by the School of Medicine of Sun Yat-sen University mentions the ABC levels of sun protection - A.Avoid (avoid exposure) > B.Block (block) > C. Cover (apply sunscreen).

Traditional parasols can only block UVB, which is basically the same effect as ordinary glass windows. They cannot block most of the damage to the skin caused by the sun, while special sun umbrellas can protect against ultraviolet rays.

A certain brand of black plastic sun umbrella

How do we choose a reliable sun umbrella? Look at the UPF!

The sun protection performance of sunscreen is indicated by SPF, while the sun protection performance of sun umbrellas depends on the UPF value. UPF ( Ultraviolet Protection Factor ) is the abbreviation of ultraviolet protection factor. The higher the UPF value, the better the protection effect of the umbrella against ultraviolet rays. For example, a UPF value of 50 means that only 1/50 of ultraviolet rays can pass through the umbrella body (that is, the fabric of the umbrella).

Common sun protection umbrellas are mostly coated with black glue, silver glue and colored glue, and the UPF can basically reach 50+.

A brand of professional outdoor sun protection umbrella

If you need to do outdoor activities, it is recommended to use a professional outdoor umbrella. The outdoor umbrella uses the world's most advanced ultra-thin titanium metal uncoated umbrella cloth, which can provide professional-level sun protection. The durability of the umbrella surface is very good. The ultra-thin umbrella cloth can also reduce the heat accumulation effect. Some have a double canopy ventilation system to dissipate heat and ventilation on the top of the head without being too hot.

With the advancement of technology, the means and methods of sun protection are becoming more and more diverse, and the sun protection products we can choose are also constantly evolving. Sunscreen and sun umbrellas are only part of it. There are also many things to try, such as sun protection glasses, sun protection clothing, and sun protection hats. I hope that this summer, you can find the sun protection products that suit you best, and have sparkling white skin while enjoying the sun.