As the temperature rises, the sun is getting hotter and hotter on our face and body, and the sun is the main factor that causes skin aging and the formation of skin surface spots. Therefore sunscreen is about to become the most used cosmetic product, especially by women. The use of sunscreen should start from spring. Although there are many different types of sunscreens, the classification is very simple, one is chemical sunscreen ingredients and the other is physical sunscreen ingredients. Chemical sunscreen ingredients are mostly organic, sun protection index (SPF) value is relatively high, the role of stable, no toxic side effects. The active ingredients are generally: dibenzoylmethane, benzophenone, dimethyloctyl alcohol, p-aminobenzoic acid, cinnamic acid salt, dihydroxyacetone, phenols, and the drug anti-inflammatory pain. Some products are two or two ingredients used, usually good results. Chemical sunscreen ingredients are more convenient, which is the reason why sunscreen is not very expensive. Some premium products are usually the difference in additives and processes such as fragrance added ingredients. Physical shading agents are also common sunscreen ingredients, usually 10% titanium dioxide, 10% zinc oxide, pearl powder, etc. Some friends say their sunscreen has a smell similar to rust, this sunscreen belongs to the physical shading agent. The most important thing about using sunscreen is to choose to use it for your own skin photosensitivity. Here is a comparison table that can help to roughly determine your skin’s light sensitivity for your reference. According to the different sensitivity of the skin to light, the medical classification into six types: 1, there is always a burning reaction, never tanning reaction 2, often have a burning reaction, sometimes tanning reaction 3, sometimes have a burning reaction, often tanning reaction 4, from no burning reaction, always tanning reaction 5, moderate whole body skin pigment deepening 6, obvious whole body pigment deepening 70% of our women in China belong to the third category of skin, need to pay attention to sunscreen Protection against UVA (long-wave ultraviolet rays). Choose the appropriate factor of sunscreen: the higher the SPF value, the longer the sun protection time. The average yellow skin can withstand the sun for 15 minutes on average without getting burned, so using an SPF 15 UV light protection product will give you about 225 minutes (15 minutes x SPF 15) of sun protection time. You can use SPF5-8 sunscreen for daily care, shopping and shopping, and SPF10-15 sunscreen when you go out for fun. When swimming or sunbathing, use SPF 20-30 waterproof sunscreen. Travel to the beach or areas with high altitude should be equipped with sunscreen with a higher SPF. The time of use should be appropriate: sunscreen should not be used before applying makeup, nor should sunscreen be applied only when you are about to go out. Sunscreen, like general skin care products, takes a certain amount of time to be absorbed by the skin. So, sunscreen should be applied 10-20 minutes before going out, and 30 minutes before going swimming. Sunscreen should be applied frequently, such as swimming at the beach, every time you go ashore should be timely reapplied, engaged in sports, sweat will make sunscreen loss, should also pay attention to timely reapplication. The amount used should be sufficient: usually sunscreen is applied on the skin at 2 mg per square centimeter in order to achieve the proper sunscreen effect. Choose sunscreen products suitable for your skin type: oily skin is appropriate to choose water-based sunscreens with strong penetration; while dry skin is appropriate to choose cream sunscreens; neutral skin is generally not strictly regulated. Do not mix different brands of sunscreens. For sensitive skin, it is best to use it for 1 week behind the ears or on the neck first, without allergies, before you can use it on a large scale.