When I returned from my long vacation, many of my friends sent me photos of their sunburns, asking for advice; others were particularly puzzled: how could they get sunburned when it was raining and cloudy every day? Summer is still early, spring also sunscreen? Sunscreen, how to do? 1, sunscreen: every season to grasp the human skin damage caused by ultraviolet radiation according to different wavelengths are divided into UVA and UVB two kinds, and ultraviolet energy has seasonal differences, UVA in the spring is the strongest, UVB in the summer is the strongest. UVA is long-wave ultraviolet light, the greatest impact on the skin, can directly penetrate the epidermis to reach the superficial dermis, can cause a variety of photosensitive diseases, but also caused by skin photoaging, and even skin tumors of the culprit. Even when it is cloudy and raining, UVA can pass through the clouds and reach the ground.UVB is a short-wave ultraviolet ray, the penetration ability is not as good as that of UVA, which mainly causes damage to the epidermis, such as sunburn. As long as outdoor activities during the day, regardless of the season, weather, should be sunscreen. 2, sunscreen: not only sunscreen, comprehensive is the king’s way The first thing that comes to mind is sunscreen, in fact, a variety of sunscreen methods: avoid the strongest UV irradiation out of the time (10AM-2PM); choose the right clothing sunscreen, long-sleeved do not have short-sleeved, can have a collar do not have a round neck, and the different textures and thicknesses of the clothing UV protection coefficients are not the same: polyester>wool>silk>nylon>cotton, wet clothing Sunscreen ability is significantly smaller. Wide-brimmed hats, sunglasses, umbrellas are effective methods of sun protection. These methods should remember to use together Oh! 3, sunscreen: “shield” and “magician” combination of dermatologists to reach a consensus on the ideal sunscreen, it is best to meet the following four conditions: ① full-band protection; ② security, chemical stability, photostability are good; ③ non-stimulation, non-toxicity; Waterproof and anti-sweat function. Any sunscreen on the market, containing sunscreen ingredients are basically fixed, only according to the product demand for different ingredients. China’s “Hygienic Standard for Cosmetics” lists 28 kinds of sunscreen agent, roughly divided into two categories: physical sunscreen agent: as close “shield”, through physical shielding, refraction and reflection of light to achieve the effect of sunscreen, commonly used is zinc oxide and titanium dioxide; chemical sunscreen agent: more like a “magician! Chemical sunscreens: more like a “magician”, absorbing ultraviolet rays and releasing them through a chemical reaction that converts light energy into a kind of heat energy on the skin surface. New sunscreens: also known as biological sunscreens, is one of the hot spots on the market, such as beta carotene, VitC, VitE, selenium, green tea polyphenols, niacinamide, retinoic acid, and other such bioactive substances. But this type of sunscreen can also be taken orally to sunscreen oh! As far as the current market is concerned, chemical sunscreen ingredients account for the majority, is the main force in a variety of sunscreen. 4, sunscreen: how to choose how to use PA index on behalf of what? SPF and PA is a commercially available sunscreen common two indexes. SPF is protected by sunscreen products on the skin surface caused by the smallest sunspots required for ultraviolet energy and no protection of the skin caused by the same erythema required by ultraviolet energy ratio. For example: when no product is applied, redness occurs after 1 minute in the sun, and when SPF 30 sunscreen is applied, redness of the skin does not occur until after 30 minutes in the sun. Therefore, SPF is the embodiment of the ability to protect UVB; PA is caused by the product protection of the lowest skin pigmentation required energy and unprotected and produce the same pigment energy ratio, so PA and SPF, is also a protective ability to labeling, PA is aimed at the UVA. often buy the products of the beauty of the eyebrow will find that foreign sunscreen products will be labeled to the 50, or even 80, while the domestic for the greater than 30 products, only labeled to 30 +. Some people are concerned about whether the domestic sunscreen sunscreen efficacy and foreign gap, in fact, each product efficacy determination, we have done specific values, including many products greater than 30, only in accordance with the relevant provisions of the domestic cosmetic health norms unified only. Common misconceptions about the choice of sunscreen: ① The higher the index, the better. In daily life, choose SPF15 or so, PA++ can be. First of all, too high index caused by the artificial reduction of repeated application frequency, but affect the effect of sunscreen; secondly, the index of high products are generally compounded with different sunscreen ingredients, causing skin irritation or allergic reaction rate is relatively high; third, the high index of sunscreen photostability and the actual effect of sunscreen is closely related to the light stability of the evaluation of the light stability of the method is still in the process of figuring out. Of course, if you want to carry out prolonged outdoor activities, you can choose a higher sunscreen index sunscreen products. ② Apply too thin. Physical sunscreen ingredients in the sunscreen will be slightly greasy, so many girls with only a thin layer, which does not play a sunscreen effect. According to the international standard for human testing of sunscreen, its use 2mg/cm2, the thickness and 1-2 A4 paper thickness is almost it! Survey shows that most people are accustomed to using the dose of only about 0.75mg/cm2, only one-third, which is far from being able to achieve the protective effect promised on the product packaging, in order to achieve the labeled effect, must try to apply thick Oh! ③See the sun before applying. Chemical sunscreen agent is the main force of sunscreen, therefore, need to give them enough time to produce a chemical reaction with the skin, so as to play a role. So generally recommended to go out 20min before applying good. ④Not repeated application: Due to various reasons such as sweat dilution, sunscreen agent’s own degradation and related ingredients’ continuous reaction with ultraviolet rays, general sunscreen will be ineffective in about two hours, so if you are outdoors for a long period of time, you need to apply every two hours; ⑤You need to use make-up remover oil in order to wash it clean. Physical sunscreen particles are relatively large and need to be carefully cleaned, but now the particles are getting finer and finer, so they can be cleaned with a general cleanser and do not need to be specifically removed. Different groups of people on the choice of sunscreen: outdoor work, plateau people, pregnant women are important people who need protection, as long as no sunscreen allergy, can be used without worry. Daily outing is recommended to use SPF15 or so, PA + + + about the sunscreen. Some people claim that sunscreen starts from childhood, and there are indeed studies proving that the regular use of sunscreen from the age of 18 can reduce the incidence of melanoma and malignant invasive melanoma by 50% and 73% respectively. But for children under 6 months need to follow the doctor’s advice: sunscreen safety trials have not yet involved children less than 6 months; its human efficacy tests are mostly conducted in adults; most importantly: moderate ultraviolet exposure for children’s bone development is very important, “sun” or “preventive The most important thing is: moderate UV exposure is very important for children’s bone development, so whether to “sun” or “prevent” needs to be weighed.