With the destruction of the ozone layer, more and more ultraviolet rays penetrate the earth, and there are more and more sunny days under climate change. Outdoor activities, such as camping, road running and seaside activities, have become a necessary action every day! In fact, the concept of sun protection existed in ancient Egypt! Women in ancient Egypt would mix rice bran extract, jasmine flower, white lupine flower and so on. And apply calcite or clay as an adhesive to their skin as a sunscreen!
In fact, it was not until 1800 that scientists realized that ultraviolet rays were the cause of sunburn. Dr. Tang, director of the Medical Beauty Center of Guangxin Hospital, explained that ultraviolet rays affecting skin conditions can be divided into the following two types according to wavelength:
● UVB (wavelength 290 ~ 320nm): mainly causes sunburn, inflammation and pigmentation; Sunscreen is marked with SPF coefficient.
● UVA (wavelength 320 ~ 400nm): it is mainly a risk factor for aging, pigmentation and even skin cancer; The protective power of sunscreen is expressed by PA coefficient.
Sun protection products are divided into two categories according to the sun protection principle. The first is chemical sunscreen: the structure of sunscreen is used to absorb sunlight, and UVA and UVB are converted into harmless heat energy and emitted. Common ingredients are: cinnamate and salicylate (against UVB); Benzophenone (both against UVB and UVA) and so on. Generally, in order to effectively block UVA and UVB, two or more chemical sunscreens are used. However, some chemical sunscreen ingredients can cause allergic dermatitis, and people who have had allergic reactions to sunscreen products should avoid using them.
In addition, friends who like diving or snorkeling should also pay attention to that some chemical sunscreen ingredients are not ocean-friendly. Studies have shown that some chemical sunscreens can accelerate coral bleaching, so Hawaii and Palau have banned tourists from bringing sunscreens containing the following ten ingredients into the country:
? Hydroxybenzophenone (benzophenone -3): Hydroxybenzophenone (benzophenone-3)? Ethyl paraben: p-hydroxybenzoic acid? Octoxyoctyl ester: octyl methoxycinnamate? Butyl paraben: Butyl paraben? Octyl cyanodiphenyl acrylate? 4- methylbenzylidene camphor: 4- methylbenzylidene camphor? Benzyl paraben: benzyl benzoate? Triclosan: Dichlorophenoxychlorophenol (Triclosan)? Methyl nipagin: Methyl nipagin? Phenoxyethanol: phenoxyethanol
Then there is physical sun protection, which uses the principle of refraction, scattering and reflection of solar light (like a mirror) to prevent sun protection. Common ones are zinc oxide and titanium dioxide. Physical sunscreen is currently recognized as an ocean-friendly sunscreen ingredient with low allergic probability, so it has gradually become the mainstream of sunscreen ingredients in recent years, and physical sunscreen itself has good stability and will not reduce its effect with time or light. In addition, it not only has a good protective effect on UVB (sunburn), but also has an excellent protective effect on UVA (tanning). Not only that, chemical sunscreens may pose fewer potential dangers.
As safe and comfortable as applying a layer of invisible sunscreen to the skin, it can effectively prevent the influence of solar ultraviolet rays on skin aging and injury. The dermatology department of National Taiwan University Hospital tested the natural beauty physical whitening sunscreen SPF35 on the skin of 40 subjects. The results of irritation and allergy tests were both 0%, which indicated that the product was hypoallergenic.
Dr. Tang reminded everyone that there are some selection criteria when choosing sunscreen products. First of all, you can choose lotion, cream or spray according to the texture. For the functional part, if you exercise for a long time or sweat easily, it is recommended to choose waterproof and sunscreen products when you go to the beach, and you should be able to block UVA (PA++ above PA++) and UVB(SPF & gt；; 30) Mainly; Finally, if you are a child with sensitive skin or six months old, it is recommended to use physical sunscreen. To sum up, sun protection is definitely the key to skin health!