Analysis:
The principle of sunscreen is to isolate skin from ultraviolet rays.
20 essential knowledge of sun protection
I talk about sun protection every year, but do you really know all about sun protection? This year, Co *** o swept away all possible sun protection problems and gave you a refreshing summer.
There is no doubt that the concept of sun protection has been recognized by more and more women in China. Vichy conducted a survey on women in Shanghai in 2003. As many as 69% women use sunscreen products in summer, with an average of six times a week. This year, all major brands have introduced new products with high sun protection value. Even if the sun protection value of the original products is increased, we can see the importance attached to the sun protection market.
But it is followed by all kinds of questions about sun protection knowledge. COSMO selects the most representative 20 questions from readers' letters, so that you can do your sun protection homework before summer comes.
1. I stay in the office every day. Do I need sun protection?
Of course, sun protection is a daily lesson. You should know that UVA ultraviolet rays that cause skin aging have strong penetration. It can penetrate glass and clouds and directly enter the dermis of the skin, causing direct damage to the skin. Therefore, you should also wear sunscreen in the office, choose those sunscreen or sunscreen with lighter texture, or choose sunscreen with maintenance function, generally SPF 15/ PA+ is enough. It should be emphasized that sunscreen or cream can't block computer radiation, and the most important means to eliminate radiation is to do a good job of cleaning every night.
2. In recent years, in addition to SPF, the word PA has also appeared on sunscreen. What does this mean?
Nowadays, sunscreen products often see the letter "PA". At present, science has confirmed that UVA- 1 is the killer of skin aging, so Japanese scientists have developed a sunscreen that specifically resists UVA- 1, and used "+"to indicate the defense strength. The correct statement of PA is to protect UVA- 1, and its degree is marked with+,++and++. The more "+",the better the effect of preventing UVA- 1.
3. I also saw SPF 30+ sunscreen products this year. What does this mean?
SPF30+ is a product higher than SPF30, which mainly comes from a new regulation of China Ministry of Health in 2003: In order to prevent the behavior of blindly soaring SPF value, all sunscreen products above SPF30 are not labeled with a specific SPF30+, and the products that pass the inspection before the release of this regulation still maintain the original labeling method. Therefore, it is best to consult the counter staff before purchasing such products in the future.
4. What is the minimum sun protection value for seaside sun protection? How much is the office?
The sunscreen applied on the beach must be higher than the office SPF, generally above SPF30/PA++, and it should be waterproof, uniform and thick. In the office, SPF 15/ PA+ is enough. Of course, in hot summer, if you encounter strong ultraviolet rays on your way to and from work, you'd better choose SPF25/ PA++ sunscreen products.
5. How often do you replenish sunscreen after going out to sea? Do I need to make up every time I go into the water?
To be precise, when swimming in the sea, you should rub it again every time you go ashore. If it is not washed away by the sea, you should rub it again at least every two hours.
6. Do you want to use different sunscreen for your body and face?
In fact, there is no strict difference. Generally, if there is no special label on the special sunscreen, the body and face can be used together. It's just that if you want to play in the water, you really need to use a sunscreen specially prepared for your body-waterproof and sweat-proof, which is not easy to wash off, and this product is not suitable for your face.
7. Are the characteristics of several sunscreen products (sunscreen oil, sunscreen cream and sunscreen liquid) different? Is sunscreen waterproof?
The texture of sunscreen products now is very different from that of previous years. Generally, the texture is very refreshing and light, even SPF50 products will not have a heavy feeling. Cream-like sunscreen products are still the most common. Spray-like liquid products are refreshing and easy to use, while oily or pasty products generally have good waterproof and sweat-proof effects, but they will feel obviously uncomfortable when applied to the face and are generally used in the body.
8. What are the different applications of sunscreen foundation, sunscreen and sunscreen?
If you are a 9-to-5 office worker who needs light makeup, sunscreen foundation is a very convenient choice, and it is easy to make up makeup. If you don't like foundation and want to improve your skin color moderately, sunscreen with slight makeup function can meet your needs; If you don't need makeup at all, or you will be exposed to strong sunlight during the day, it is best to use sunscreen with an appropriate index. As for the difference between sunscreen and sunscreen, it is mainly because sunscreen generally has the function of correcting skin color and helping foundation to apply makeup more easily.
9. I know that the sunscreen will expire in a few hours, so how can I make it up when I put on makeup? There is a lot of sweat on my face. How to make up for sun protection?
You know, sun protection is a science! Many girls know about sun protection, but they often apply several layers of sunscreen directly on their faces, and as a result, they may "make up" terrible fat particles! Here are a few tips for makeup and sun protection: after makeup, you can gently wipe off sweat and oil with a paper towel, or just use oil-absorbing paper to absorb oil, and then use sunscreen powder to make up your makeup; If there is a lot of sweat and oil on your face, be sure to wipe it off with a makeup remover before applying sunscreen. You can also use hydrating spray to clean your face before applying it.
10. Do children need sun protection?
Sun protection for children is very important. Before the age of 8 ~ 9, children's skin is not yet mature, and their ability to resist ultraviolet rays is still weak, and they often stay in the sun for a long time. It is estimated that the amount of ultraviolet rays irradiated on children is three times that of adults. Without protection, the longer and more frequent skin exposure (especially in childhood), the greater the risk of skin cancer in adulthood.
1 1. I'm afraid of tanning, so I want to use whitening mask immediately after tanning. Is it okay?
I have seen friends around me do this, and as a result, skin rashes and other sensitive phenomena have appeared. This is because sunburned skin is very dehydrated and has some inflammatory reactions, so when you apply an acidic whitening mask on your face, it is equivalent to increasing the sensitivity.
The correct way is to use hydrating mask immediately after sun exposure. Gel or paper film hydrating mask is especially recommended. If possible, it would be better to freeze it in the refrigerator. After drying, dehydrated skin will naturally restore the healthy state of stratum corneum after cooling and hydrating. As for the whitening procedure, it is not too late to use it after the skin is completely stable.
12. Is ultraviolet light stronger as it gets hotter?
Ultraviolet rays will not give off heat. For example, climbing a mountain, the higher you go, the colder the mountain wind, and people may even feel cold, but at this time the ultraviolet rays are very strong. That is to say, for every rise of 1000 meters, the ultraviolet ray increases by 10%. Similarly, the wind in the sea makes you feel cool, but at that time, the ultraviolet rays have reached a strong level. Don't ignore sun protection just because you don't have a fever in a cool place.
13. I heard that the best sunscreen is a T-shirt. Is that so?
An ordinary T-shirt is better than any sunscreen, and its SPF value is about 15 ~ 30, which can really isolate 95% of ultraviolet rays, but remember that clothes lose their sunscreen effect when they are wet; In addition, the place where the T-shirt can't stop should be protected from the sun. If you go out to play, a long-sleeved T-shirt, a Panama hat or a small hat, and then coated with SPF30/ PA+++ sunscreen, is a safe combination.
14. Do you still need sun protection on cloudy days?
Clouds can hardly isolate UVA ultraviolet rays. All UVA ultraviolet rays can penetrate clouds, which means that 90% ultraviolet rays can penetrate clouds. Only the thick cumulonimbus layer in the dark can block some ultraviolet rays, so it is best to use SPF 10- 15 products on cloudy days.
15. My skin is sunburned enough, so I don't need sun protection?
After sun exposure, the skin will turn brown, indicating that the skin has entered a state of self-protection-skin thickening and melanin production are all manifestations of skin self-protection. Melanin can only partially absorb ultraviolet UVB, which can isolate the skin from harm, but it has no function of absorbing ultraviolet UVA, so even tanned skin will be damaged by UVA, and it also needs sun protection.
16. What should I consider before buying sunscreen?
When purchasing sunscreen products, most people choose the sun protection factor (SPF), which is not comprehensive. Before buying, you should consider your work nature, living habits, skin color, age and other factors. For example, for office women who have been indoors for a long time, the coefficient of SPF 15 is enough. If they often run around outside, it is best to choose SPF20 or above. If they like to engage in water sports, SPF must be raised to SPF30 or even higher; In addition, people with fair skin should also choose sunscreen products above SPF 25 to prevent spots; And if the skin is dark, use SPF 15 products on weekdays.
17. Last time I went out to play, my skin got sunburned. I heard it would be better to wait until autumn. Is that so?
After-sun care is best carried out on the day or even at that time of sun exposure. The earlier the time, the less the skin damage. Sunlight will make the skin lose a lot of water, resulting in rough skin epidermis, so "moisturizing and calming" is the focus of post-sun care. If you can do a good job of after-sun care at the first time after sun exposure, it will not only reduce the redness, swelling and burning pain of the skin, but also help to slow down the damage of ultraviolet rays. Ice cubes, cold water bath and hydration condensation are all good methods for post-sun care.
18. I heard from friends that the damage of ultraviolet rays will accumulate. Is it true?/You don't say.
Our skin's memory system will record the degree of damage caused by sunlight every time, and gradually accumulate it. With the increase of exposure time to the sun, the sunlight energy in the skin is gradually consumed, which will eventually fail to protect our skin. Generally around the age of 20, it will consume 50% of the "sunshine capital". Due to individual differences, the speed at which sunlight disappears in everyone's skin is different.
19. People say I have photophobia. Use sunscreen first, then sunscreen foundation, and finally sunscreen powder every morning to make yourself feel fully prepared for sunscreen. Did I do the right thing?
If you think that a SPF20 day cream and an SPF 15 foundation can achieve the sunscreen effect of SPF35, then you are all wet! In fact, this practice will not only increase the burden on the skin, but also always have the sunscreen effect of SPF20. When two different sunscreen products are used together, the effect is based on the product with high SPF, so I suggest you choose one sunscreen product to use.
20. How long does it take for sunscreen to be applied to the skin to really exert its sunscreen effect?
The principle of sunscreen is to isolate skin from ultraviolet rays. Because the isolation component must penetrate into the cutin surface layer, it can play a long-term absorption and isolation effect, so it must be wiped 20 minutes before going out and supplemented again before going out, with good effect; The dosage should be at least 1-2ml each time to achieve the best isolation effect. And should try to avoid going out during the strongest sunshine period (10 am to 2 pm); At the same time, we should make good use of various auxiliary items, such as umbrellas, hats, long-sleeved clothes and sunglasses. , to resist the invasion of ultraviolet rays.