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Anonymous users2024-02-071. It is very important whether the strength of the PA value is sufficient
Sunscreen should not only protect against UVB, but also against UVA, because UVA can reach deeper and cause greater damage.
2. Low-magnification sunscreen products can be used for the face
The higher the SPF value, the higher the better, and the higher the SPF value, the greater the burden on the skin. Make-up once every two hours or so
3. No matter how high the SPF value is, remember to reapply regularly to ensure the sunscreen effect.
4. Sun protection is needed all year round
Sun protection is an essential final step in your skincare routine.
5. I often see sunscreen products marked with SPF and PA, what do they mean?
SPF: Represents the protection factor of ultraviolet UVB, and 1 SPF value represents how long the skin can be sunburned without any protection (yellow people** can generally withstand the sun for an average of 20 minutes). Use SPF-15 sunscreen for about 5 hours (20 minutes SPF-15).
PA: Stands for the protection factor of ultraviolet UVA, and its degree is expressed in terms of "three intensities," the more words, the better the effect.
Therefore, it is more important to choose a product with a greater PA "+" strength, rather than simply looking at the size of the SPF value. Limi's full range of sunscreen products are PA+++ UVA UVA protection factor is very strong.
6. The higher the SPF value, the higher the degree of blocking ultraviolet rays, is the higher the SPF value, the better?
SPF15 is enough to block 95 UVB rays! SPF30 is enough to block nearly 100 UVB rays!
Therefore, the higher the SPF value is not unlimited, the better.
In addition, the higher the SPF value, the more sunscreen ingredients are added to the sunscreen, and the greater the burden on the skin.
Therefore, it is important to choose the right sunscreen product, and not just focus on the SPF value.
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Anonymous users2024-02-06SPF: Sun Protection Factor, which indicates the level of sunscreen effectiveness that can be exerted by sunscreen varieties. It is calculated based on the lowest dose of erythema.
PF = Minimum Erythema Dose (after using sunscreen) Minimum Erythema Dose (before using sunscreen) The SPF value is applicable to each person, and it is calculated as: assuming that the intensity of UV rays does not change over time, a person without any sunscreen will turn red after 20 minutes in the sun, and when he uses SPF15 sunscreen, it means that he can extend the time by 15 times, that is, after 300 minutes** will be tanned. SPF is a measure of a sunscreen's ability to defend against ultraviolet rays in the sun.
Although SPF is an important indicator of sun protection, it does not mean that the higher the SPF value, the stronger the protection. For example, SPF15 has 93% protection, while SPF34 only has 79% protection, but the larger the SPF value, the worse its permeability, which will hinder the normal secretion and respiration of **. According to the research of ** medical experts, in terms of Oriental skin type, SPF10 SPF15 sunscreen can be used for daily protection; If you engage in outdoor recreational activities such as swimming and playing ball, SPF20 is enough to resist UV damage without burdening your skin.
When we buy sunscreen products, we must read the instructions carefully, choose the appropriate sun protection factor (SPF value) of the product, and find out whether the product has the function of UVA protection.
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Anonymous users2024-02-05Many sunscreens on the market today are marked with SPF values, and the higher this value, the stronger the sun protection. So what exactly does SPF mean?
SPF 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.
Redness after sun exposure, medically known as "erythema", is the mildest reaction to sun exposure. The lowest dose of erythema is the shortest amount of time spent in the sun. If the minimum dose of erythema increases** after using a sunscreen, the SPF of the 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 spend 8 times as much time in the sun (i.e. 120 minutes), and so on.
SPF is currently the most widely used index to characterize the sunscreen efficacy of sunscreen products in the world, and it is generally determined by human tests or other methods abroad. At present, there is no standard for measuring SPF value in China. In this experiment, another international method for evaluating the sunscreen efficacy of sunscreen products was used - spectroscopy.
It evaluates the sunscreen efficacy of sunscreens by measuring absorbance values (ODs), which characterize a sample's ability to absorb and reflect UV rays.
1. When buying sunscreen, pay attention to the SPF value, which is to protect against UVB rays. The higher the SPF value, the better, the higher ** the more difficult it is to "breathe", some people will have allergies, and the use of SPF in Guangzhou is only 15 to 25 is enough. When choosing sunscreen products, you should also pay attention to preventing UVA rays, which are represented by PA, and the more plus signs, the better the sunscreen effect.
2. When to apply sunscreen: Arrange to apply it 15 minutes before going out, because the sunscreen will only work after 15 minutes after rubbing.
3. All parts of the body should be rubbed, especially in places with strong ultraviolet rays.
4. Apply sunscreen to the back of your hand and sprinkle it with water, it is best to pick one that can form water droplets.
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Anonymous users2024-02-04Do you really know about sun protection? What exactly does PA and SPF mean? If I don't know, the sunscreen is white.
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Anonymous users2024-02-03Sun Protection Factor (SPF) refers to the SPF sun protection factor, which is a detection index that measures the ability of sunscreen products to defend against ultraviolet rays in the sun, indicating the level of sunscreen efficacy that sunscreen products can play. It is determined based on the lowest erythema dose.
The SPF is SPF2 6 for low-grade sunscreens, SPF6 8 for medium-grade products, SPF8 12 for high-level sunscreens, and products with SPF values in the range of 12 30 are considered high-strength or ultra-high-strength sunscreens.
According to the "Hygienic Standards for Cosmetics" officially implemented in China on July 1, 2007, when the SPF value of the measured sunscreen cosmetics product is higher than 30, and it is still greater than 30 after subtracting the standard deviation, the maximum SPF can only be marked with SPF30+, but not the measured value.
The announcement on the issuance of the administrative requirements for the labeling of sunscreen cosmetics (Announcement No. 107 of 2016 of the State Food and Drug Administration) requires that "the labeling of the sun protection index (SPF) shall be based on the SPF value actually measured by the product". According to the requirements of the method for the determination of the sun protection index (SPF) of sunscreen cosmetics, taking into account the sampling error during the determination and the traditional labeling habits of the cosmetics industry, the labeling value of the sun protection index (SPF) of sunscreen cosmetics should follow the following principles:
1) When the SPF value is 2 5 (including 2 and 5), the measured SPF value is identified;
2) When the SPF value is 6 50 (including 6 and 50), the upper limit of the logo is the measured SPF value, and the lower limit of the logo is the smaller value between the lower limit of the confidence interval of 95% of the measured value and the maximum integer multiple of less than 5 of the measured value.
3) When the SPF value is greater than 50 and the lower limit of the 95% confidence interval of the measured value is greater than 50, the sun protection index (SPF) of sunscreen cosmetics should be marked with "50+"; When the SPF value is greater than 50 and the lower limit of the 95% confidence interval of the measured value is less than or equal to 50, the upper limit of the logo is "50+", and the lower limit of the indicator is the lower limit of the 95% confidence interval of the measured value.
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Anonymous users2024-02-02Products with only SPF indicators cannot protect against ultraviolet ultraviolet (UVA), which causes the destruction of dermal collagen fibers and causes aging. The most important cause of wrinkles. Sunscreens with relatively high PA protection levels can effectively block ultraviolet rays and protect the skin, so choosing products labeled with SPF and PA can prevent UVA and UVB damage to the skin at the same time.
If the sun is not serious, it will be darker, and if you are exposed to the sun for a long time, you will get sunburned. I think they are different in degree.
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Anonymous users2024-02-01SPF value refers to the time of protection against ultraviolet rays, and generally the higher the SPF value, the longer the resistance time. However, it is OK to use SPF value of about 30 for daily use, and it is OK to go shopping with SPF30+ for people like the butterfly makeup sea blue sunscreen I use!
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Anonymous users2024-01-31How to choose the sun protection factor:
1. If you usually go to work, choose SPF15 and PA+ products.
2. For outdoor sports, it is advisable to choose SPF25 SPF35 and PA++ products.
3. When swimming at the beach, choose SPF35 SPF50 and PA+++.
Others: The smaller the SPF value, the worse the sun protection effect; The higher the SPF value, the better the sun protection.
PA+ stands for maintenance, and PA++ stands for good maintenance.
PFA 2-4 mild sun protection, effective protection time 2-4 times, and so on.
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Anonymous users2024-01-30It has been said in the news that anything higher than SPF 30 will not have a noticeable effect.
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Anonymous users2024-01-29In the summer, you can use 30's.
It should also be used in winter.
Snow also has radiation.
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