Sunrise and sunset, week after week, people are more than familiar with the sun, which gives everything life force at the same time, but also left traces of everything …… For beauty lovers, these traces are often manifested in the darkening of skin color, skin laxity, deepening wrinkles. So, with the arrival of the hot summer and the intense sunshine, it is necessary for us to understand the sun! What is the solar spectrum? It would be narrow-minded to think that the solar spectrum is the warm winter and blistering summer sunlight we see every day! In fact, we can see only the visible part of the solar spectrum, the wavelength of about 380nm ~ 780nm, according to the wavelength of the ascending order of violet, blue, blue, green, green, yellow, orange, red, which only accounts for a very small part of the solar spectrum. Wavelengths greater than 780nm and less than 380nm of light will not be perceived by our vision, but it does exist. Among them, greater than 780nm near, medium and far infrared, often used in the field of medicine, longer than infrared wavelengths of light there are microwaves, industrial airwaves and so on. So what is shorter than 380nm spectrum? Is the “famous” ultraviolet, X-rays, γ-rays. Today we focus on understanding the invisible ultraviolet Vacuum ultraviolet UVD will be strongly absorbed after encountering oxygen, can not reach the ozone layer, can only exist in a vacuum, we can put it PASS! Short-wave ultraviolet UVC after reaching the ozone layer will be depleted with the ozone is constantly generated, so the ultraviolet reached the surface of the Earth’s ultraviolet UVC is almost 0, you can PASS! The real UVB that can reach us is about 3% of the total amount of UVB that radiates to the human body. Here’s the kicker! UVB mainly damages the epidermis, causing sunburn, skin peeling, erythema, tanning and other symptoms, but it can be blocked by glass, umbrellas, clothing, etc., so it is also known as “outdoor ultraviolet”. UVB can make the bottom layer of the epidermis and the basal layer of the melanocytes activated, through a series of reactions to produce melanin, and transferred to keratinocytes, melanin transferred to keratinocytes. The more melanin transferred to the keratinocytes, the darker the skin color. In fact, the whiter the skin color, the lower the melanin content of the epidermis, the more prone to sunburn. You’re white and you don’t wear sunscreen? UVA accounts for about 97% of the ultraviolet rays that reach the earth’s surface, and here comes the danger! —- It can not only cause skin darkening through the above mechanism, but also cause skin aging culprits, is also the culprit causing skin cancer! UVA will be refracted into the indoor, also known as “indoor UV “UVA-induced photoaging is often characterized by sagging skin, deepening wrinkles, and a decrease in the skin’s water content, due to the fact that it breaks down collagen and elastin fibers and reduces the amount of hyaluronic acid. Tell an old driver’s story! A 69-year-old truck driver, after 28 years of driving, because the left half of the face than the right half of the face long-term exposure to more ultraviolet rays, resulting in serious photoaging, the formation of “half-face aging disease”. Since UV rays have such a great impact on the skin, then we should how to prevent sunburn, in addition to umbrellas, hats, sunscreen clothing, in fact, the most commonly used and effective method is to apply sunscreen, then the sunscreen sunscreen principle and how it is? Please pick up the sunscreen, while looking at the ingredient list, while looking at this children’s content. There are two main physical sunscreen ingredients, zinc oxide and titanium dioxide, which play a role in scattering and reflecting UV rays. Zinc oxide can reflect and scatter UVA and UVB, low concentration of titanium dioxide can block UVB, more than 5% of titanium dioxide can block UVA. physical sunscreen safety is high, but makeup feel heavy, according to the personal requirements of makeup feel to choose. Chemical sunscreen ingredients are mainly p-aminomethylbenzoic acid, salicylic acid, cinnamic acid, camphor derivatives, phenyl ketones, triazines, dibenzoylmethanes, phenyl benzimidazoles. More common in the sunscreen ingredients list are ethylhexyl methoxycinnamate (Cinoxate), p-phenylenedimethylene bis(camphor sulfonic acid) (Mexoryl SX), cresyltriazolium trisiloxane (Mexoryl XL), Octocrylene (Octocrylene), diethylamino hydroxybenzoylbenzoic acid hexyl ester (Uvinul A Plus), bis -ethyl Hexylidene phenol methylaminophenazine (Tinosorb S), Polysiloxane-15 (Parsol SLX), Methylenebis(benzotriazolyl)tetramethylbutylphenol (Tinosorb M), and so on. Chemical sunscreens provide sun protection by absorbing ultraviolet rays, and the sun protection effect will decay with time, so they need to be reapplied intermittently. Chemical sunscreens have a more refreshing texture and are suitable for oily skin as they don’t have an overly made-up look on the skin after application. Of course, some chemical sunscreen ingredients are less safe and can cause skin irritation or damage, especially for people with sensitive skin, who need to be more cautious about chemical sunscreens, which we will push articles about chemical sunscreen ingredients specifically in the future. Physical sunscreen and chemical sunscreen have their own characteristics, in order to bring out the advantages of these two methods, the combination of physical and chemical sunscreen sunscreen creams on the market more and more, to a greater extent, to meet the needs of people with different skin types. We can choose the right product for ourselves based on the objective condition of our skin and our sunscreen needs!