The sun is getting hotter and hotter as the flowers bloom. In the face of the blinding sun, it is a top priority for many beauty lovers to choose a suitable sunscreen product to protect their delicate skin from the sun’s scorching rays. A good choice of sunscreen can not only prevent tanning and sunburn, but also be effective in anti-aging. Let’s learn more about sunscreen ” What are the UV rays in the sun? The ultraviolet rays in the sun are divided into UVA, UVB and UVC. 1, UVC wavelengths are the shortest, the most damaging, but fortunately, basically blocked by the Earth’s outer ozone layer isolation; 2, UVB is medium and long wavelengths, is the majority of people know the UVB, the stronger the sunlight is stronger UVB, but it can be blocked by clouds, it can also make the skin in a short time sunburn, sunburn (for the average person is about 25 minutes), the vast majority of sunscreens on the market now is UVB type UVA is a long wavelength, it is invisible but penetrating, no matter how many clothes in the room or wear, still can penetrate layer by layer directly to the dermis, damage the elastic fibers, is the real sunlight killer that causes skin aging. Therefore, a good sunscreen should be a complete defense against both UVA and UVB. ” What are the SPF and PA often seen in sunscreens? SPF, the sun protection factor against UVB rays is generally expressed in numbers, the higher the SPF, the stronger the ability to prevent sunburn. 1, the general type of skin people, SPF value should be with the seasonal changes to make the appropriate choice; 2, people sensitive to light, SPF value of 12-20 is appropriate; 3, sensitive skin should pick plant-formulated sunscreen or physical sunscreen containing titanium dioxide; 4, only on the way to and from work exposure to the sun, SPF value of about 15 can be, to face sunscreen; 5, in the field to play. When swimming at the beach, the SPF of the sunscreen should be above 30, and use a waterproof sunscreen. PA, refers to the product for blocking UVA ultraviolet ray sun protection factor, with +, “+” more, said the longer the effective protection time 1, PA + effective protection time of about 4 hours; 2, PA + + effective protection time of about 8 hours; 3, PA + + + for super protection. Because a large portion of skin damage is formed by UV exposure before the age of 18, it is important to start using sunscreens earlier. Chemical sunscreens are UV absorbers, which are delicate and refreshing, suitable for oily skin, but some products can cause allergies, and the sunscreen itself is easy to decay, the sunscreen effect will slowly deteriorate, so it should be reapplied every two hours. Physical sunscreens can refract and scatter UV rays, and act as a physical barrier on the skin. It is less irritating and suitable for sensitive skin, and can be used around the eyes and other sensitive areas of the skin, but it is thick, greasy and not refreshing, and not suitable for oily skin. Sunscreen products should be used all year round, not only in summer; in addition, even if you do not go out, in the indoor line also do a good job of sun protection. How about it, you learn how to pick sunscreen? The sun is getting hotter and hotter, so be sure to protect your skin!