Sunscreens come in many forms: spray, gel, patch or topical… but generally contain physical or chemical ingredients that are able to block, absorb or spread some UV radiation on the area. skin exposed to the sun. The 3 types of UV filters that can be combined in sunscreen products are: Organic chemical compounds that can absorb harmful components of UV light (oxybenzone, sulisobenzone, avobenzone). Inorganic particles reflect, scatter and absorb UV light (titanium dioxide, zinc oxide, superoxide dismutase, phlebodium aureum). Organic particles that can reflect, scatter or absorb light (tinosorb M, tinosorb S, mexoryl XL.). The American Cancer Society recommends that people use sunscreen because it can help prevent squamous cell and basal cell skin cancers, and to use broad-spectrum sunscreens because they can provide Protects against both UVA and UVB rays. What is SPF sun protection factor? SPF (Sun Protection Factor) is a measure of the amount of UV radiation needed to create a sunburn on the skin. All sunscreens are tested to measure the amount of UV radiation exposure needed to cause sunburn when sunscreen is used compared with UV exposure to cause sunburn without sunscreen. Sunscreen. The product is then labeled with the appropriate SPF value. The SPF value indicates the level of sunburn protection provided by the sunscreen product. As the SPF value increases, the level of sunburn protection increases. Sunscreen is only effective when applied to the skin about 15 – 30 minutes before going out in the sun. Should choose sunscreen products with medium SPF, in the city only need to use products with SPF 20 – 30. A very common misconception is that consumers are often told that an SPF 15 sunscreen can provide 15 x 10 minutes = 150 minutes of sun protection without sunburn. This is not true because SPF is not directly related to the time of sun exposure but to the amount of energy exposed to solar radiation. Although the amount of solar energy is related to the length of exposure to the sun, there are other factors such as the intensity of the solar energy that can affect the amount of UV radiation. For example, the following exposures could result in the same amount of solar energy (because the sun is more intense at noon than at other times): Example 60 minutes of solar energy at 9 morning hours can be equivalent to 15 minutes at 13 pm. The intensity of UV radiation in sunlight is also related to geographical location, greater radiation intensity occurs at lower latitudes. Several other factors can affect the amount of solar radiation exposure bức – People with fair skin are able to absorb more solar energy than people with dark skin under the same conditions. – The more sunscreen used, the less solar energy is absorbed. Sunscreen wears out and becomes less effective over time so frequency of reapplying is important to limit absorption of solar radiation. The frequency of reuse is also affected by the activities the user engages in. For example, when swimming, sunscreen needs to be reapplied more often because water can wash sunscreen from the body. In addition, high levels of physical activity also necessitate more frequent use of the cream because this activity can cause heavy sweating that washes away the sunscreen. Because many different factors affect the amount of solar radiation, the SPF number does not reflect the length of time a user is in the sun. In other words, SPF doesn’t inform users about how long they can stay in the sun without getting sunburned. Instead, SPF is a relative measure of the amount of sunburn protection provided in a sunscreen. Different sunscreens will have different SPF ratings. There are sunscreens with SPFs between 15 and 100 on the market today, allowing consumers to compare levels of sunburn protection. The higher the SPF, the more protection your skin can get from the sun. But 3 times the SPF does not mean 3 times the UV protection. For example, SPF 20 sunscreen can absorb up to 95% of UV rays, while SPF 60 sunscreen can absorb up to 98.3% of UV rays; SPF 15 blocks 93% of UV rays; SPF 30 blocks 97% of UV rays; SPF 50 blocks 98% of UV rays. In Vietnam, you should choose a sunscreen with an average SPF, in the city you only need to use a product with an SPF of 20 – 30, when you go to the beach, you need to use a sunscreen with an SPF of 50+. In fact, the majority sun protection index is often not as advertised. Some surveys show that over 40% of sunscreen products with SPF sun protection do not reach the level stated by the manufacturer on the product.

Applying too little sunscreen leads to a lower SPF that prevents the skin from receiving optimal protection from UV rays. As recommended, the amount of sunscreen the size of the palm is enough for the body. As for the face, you should apply a dime-sized amount of sunscreen. Don’t reapply sunscreen often To protect your skin, reapply sunscreen every 2-3 hours. (Illustration) Sunscreen, whether applied or sprayed, degrades after 2 hours of use in the sun. If exposed to water or sweat a lot, the above time will be shortened. Therefore, it is necessary to regularly reapply sunscreen. When reapplying sunscreen, you can use makeup remover to remove the previous layer. If you’re wearing makeup, use a powder sunscreen to reapply. Skip important areas Many women think that only the skin exposed to the sun must apply sunscreen without knowing that UV rays can penetrate clothes and different layers of thick and thin fabrics. If sunscreen is not applied to the entire body, many other areas of skin can still be damaged as usual. In addition, note two places people often do not pay attention to protect when going out in the sun: eyelids and lips. The lips are especially vulnerable because they don’t have a lot of melanocytes, a protective pigment responsible for giving color to skin, hair and eyes. The more hydrated your lips are, the easier it is for UV rays to penetrate deeper into unprotected skin. For lips, you can use lip balm with SPF over 30. Do not follow instructions for use For chemical sunscreen to be effective, it needs to be applied to the skin at least 20 minutes before going outside because the skin needs time to absorb the protective ingredients. It is recommended to apply evenly and thoroughly on the skin before wearing clothes to avoid any traces or stains of cream on the clothes. Particularly for products with 2 physical sunscreen ingredients – titanium oxide and zinc oxide – will work immediately after application. So with a physical sunscreen, you don’t have to wait for the sunscreen ingredients inside to take effect. Use opened sunscreen for a long time When unopened, sunscreen usually has a shelf life of about 2-3 years. However, once used, this time is reduced to about 6 months. You should not use sunscreen that has expired, has a change in texture, color or scent because it can cause allergies and damage to the skin. Do not pay attention to the spectrum index on sunscreen Many sunscreens only work against UVB rays, the cause of sunburn. Meanwhile, UVA rays also bring many harmful effects. Carrying a longer wavelength than UVB rays, UVA rays penetrate deeper into the skin, destroying collagen structures and leading to skin aging. For maximum skin protection, look for sunscreens that have broad-spectrum formulas (on the packaging that say “broad-spectrum”) that block UVA and UVB rays. For sunscreens that use the PA character, choose a product that has the PA character with plus signs after +++ or more. Using sunscreen that is not suitable for your skin Sunscreen only works when you choose the right product, suitable for your skin characteristics. Should choose a sunscreen with an SPF of 20 – 30 for light skin, an SPF of less than 20 for dark skin, if you want to increase protection in the harsh sun, only use a sunscreen with SPF 30 50 is the best fit. People with acne-prone skin should use the spray form. This type both protects the skin and unclogs the pores, helping the skin not to be blocked by dust and sweat. Sensitive skin, prone to allergies should choose sunscreen that does not contain paraaminobenzoic acid (PABA). Like other cosmetics, improper use of sunscreen is not only ineffective, it can even cause unfortunate damage to the skin. If you are making the above mistakes, you need to correct them immediately to have smooth, healthy skin this summer. Minh Hoa (th)