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Anonymous users2024-02-07The SPF value is the main thing that will be labeled on every bottle of sunscreen. The scientific sun protection index refers to the ratio of the energy required to produce the smallest erythema on the ** coated with sunscreen protection and the energy required to produce the same degree of erythema on the ** without any protection, simply put, it is the multiple of the time to resist ultraviolet rays. For the yellow race, it was calculated like this:
The average yellow person** can withstand the sun for 15 minutes without being burned, so the use of SPF15 UV protection products will have about 225 minutes of sun protection time. Objectively speaking, the level of sun protection index reflects the UV protection ability of sunscreen products. The higher the SPF index, the greater the protection given, but the increase in SPF value is not directly proportional to the ability of the screen to block UV rays.
Generally speaking, the SPF of the lowest sunscreen is SPF2 6, the medium sunscreen is SPF6 8, the high sunscreen is SPF8 12, the SPF value is in the range of 12 20 is the high-strength sunscreen, and the SPF value between 20 and 30 is the ultra-high-strength sunscreen. However, in foreign countries, because there are many people who like to be exposed to the sun, the index of sunscreen products designed is relatively high, and some even reach SPF80. SPF Pa:
Science has confirmed that UVA 1 is the cause of skin aging**, so Japanese scientists have developed sunscreens that specifically protect against UVA 1, and use " " to indicate the strength of the defense. The correct way to say PA is Protection of UVA 1, and its degree is indicated by the three strengths, "The more you have, the better the protection against UVA." If you take a closer look at the sunscreens on the market today, you will find that many sunscreens have not only SPF values, but also have PA values clearly labeled.
Since SPF is against UVB UVB, which means that it can only defend against 1% of the total amount of UVA rays on the ground, it is powerless against the real UVA. Therefore, sunscreens for UVA will play a more effective role, and products labeled with PA have such a function in order to reach the bottom layer of the dermis in the shortest possible time, preventing ultraviolet rays from damaging the elastic fibers and causing ** aging. In general, the intensity of the PA is expressed by , and one more indicates the extension of the effective protection time.
Specifically, the effective protection time of PA is about 4 hours. The effective protection time of PA is about 8 hours.
PA Superior Protection. Inform: How to choose the right SPF value 1 for people of the general type**, an SPF value of 8 12 is appropriate; 2 For people who are sensitive to light, an SPF value of 12 to 20 is appropriate; 3 Sensitivities**Choose a plant-based sunscreen or a physical sunscreen containing titanium dioxide.
4 Office workers who are only exposed to sunlight on the way to and from work, with an SPF value of less than 15, should focus on sunscreen on the face; 5 When playing in the wild and swimming on the beach, the SPF value of sunscreen should be above 30. It's best to use waterproof sunscreen when swimming. 6.
Apply 15-20 minutes before going out.
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Anonymous users2024-02-06Hello, Know Me Cosmeceutical Skin Consultant is happy to help you.
SPF is the English abbreviation of Sun Protection Factor, which is the ability of sunscreen skin care products to protect against ultraviolet rays. The higher the SPF index, the greater the protection given to **. Different SPF values indicate different amounts of time for effective sun protection.
Specifically: SPF 15 = 15 * 10 = 150 minutes, SPF 20 = 20 * 10 = 200 minutes, and so on. However, sunscreens with a high SPF are heavier than those with a lower SPF, so be sure to pay attention to the cleanliness of your face.
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Anonymous users2024-02-05The meaning of sunscreen factor is SPF, that is, the coefficient of sun protection, which is simply sunscreen.
Generally speaking, when the SPF value is stronger, the greater the sunscreen ability, and generally outdoors we need to choose a sunscreen with a higher SPF value.
Sunscreen is a sunscreen product that many people will use in summer, especially for some people who are darker than others, sunscreen is even more important, we will see that the sunscreen factor is the value of SPF, what does this mean?
What does SPF mean The SPF is SPF, which stands for Sun Protection Factor.
It refers to the value of the sunscreen effect to prevent UVB damage, simply put, it refers to the sunscreen strength of the sunscreen, when the SPF value is larger, it means that its sunscreen effect is stronger.
How to choose sunscreen according to your skin type and physical condition: choose a refreshing oil-controlling type for oily skin, a moisturizing type for dry skin, and physical sunscreen for sensitive skin and sensitive people, such as pregnant women and children.
For those who are concerned about the use of skincare products, they can choose chemical sunscreen or hybrid sunscreen.
The difference between physical sunscreen and chemical sunscreen, by the way, what is physical sunscreen and what is chemical sunscreen. There is also a hybrid sunscreen, as the name suggests, it is a combination of physical sunscreen and chemical sunscreen, and it is recommended to choose this sunscreen product for healthy skin. Amway.
Next, how to tell if a sunscreen is a physical or chemical sunscreen?
Generally speaking, when the SPF value is stronger, the greater the sunscreen ability, generally outdoors we need to choose a sunscreen with a higher SPF value.
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Anonymous users2024-02-04SPF is the English abbreviation of Sun Proteetion Factor, which indicates the level of sun protection effectiveness that sunscreen products can exert. It is determined based on the lowest erythema dose. The first SPF50 refers to the fact that the product can absorb more than 98% of UVB under laboratory conditions (the algorithm formula is (50-1) 50*100%=98%).
If the minimum erythema dose of ** increases after using sunscreen, then the SPF of that sunscreen is: SPF Minimum Erythema Dose (after sunscreen) Minimum erythema dose (before sunscreen).
Assuming that a person's minimum dose of erythema is 15 minutes, then after using a sunscreen with SPF of 4, they can theoretically stay in the sun for 4 times longer (60 minutes) before they appear reddish; If you choose a sunscreen with an SPF of 8, you can stay in the sun for 8 times longer (i.e. 120 minutes), and so on.
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Use an umbrella or sunscreen for sun protection.
Be sure to get the barrier cream first, the barrier cream is dustproof and protect ** from being hurt by cosmetics, you can choose a barrier cream with sunscreen function, which will be more refreshing and can also achieve the effect of sunscreen.
In fact, sunscreen or isolation with sunscreen effect is difficult to prevent tanning in the final analysis, so the key is to do a good job of sunscreen measures while applying, such as playing an umbrella, trying not to go out when the sun is strong Sunscreen generally has no concealing effect, you can use moisturizing lotion before, and you don't need it afterwards (if you don't wear makeup, that's it). Physical sunscreen is safer, but not as clear as chemical sunscreen. The sunscreen must be selected with sunscreen ingredients and sunscreen effect, and the application procedure is the same as above The concealer effect is general There is also a choice of BB cream, which should also be selected with sunscreen effect. >>>More