Do you know what the SPF on a sunscreen product is about? 30

What exactly does SPF mean?

SPF stands for Sun Protection Factor, or sun protection factor. SPF is an abbreviation for Sun Protection Factor, which indicates the level of sun protection that a sunscreen product can provide. It is determined by the minimum dose of erythema, the latter value represents the time that can be extended several times.

The higher the value, the better the sun protection.

Tips to relieve the sun

1. Don't eat photosensitive vegetables, supplement vitamins, wear light-colored cotton T-shirts, massage and charge **, etc. For people who are prone to spots, it is best not to eat "photosensitive" vegetables such as celery, coriander, white radish, etc. in midsummer. These vegetables will make it easier for spot-loving ** to grow.

The body loses water quickly, so it is necessary to replenish enough water for the body in time.

2. Apply sunscreen to inform the product. Whether it is a boy or a girl, it is recommended to wear sunscreen products when you need to bask in the sun in summer. Choosing the right sunscreen can be an effective way to avoid sunburn and tanning.

Especially girls, remember to wear sunscreen before applying makeup. Long-term exposure to the sun can easily lead to aging.

3. In addition to the sun protection of the face, the sun protection of the body is also important. Try not to let the sun shine directly on you. You can also wear a sunhat and sunglasses to prevent sunburn within a certain range.

4. Eat more whitening foods. Vitamin-rich foods can effectively improve** and play a certain whitening role. Therefore, you can eat more antioxidant foods such as tomatoes, and you can also supplement vitamin E, vitamin A and calcium. It is recommended to eat more lemons, tomatoes, nuts and other foods.

What does PA mean?

The main function of PA is to prevent skin tanning or aging, and is an indicator of UV intrusion. The effect of PA can be divided into three levels, which are PA+, PA++, and PA++, which are effective, very effective, and very effective. The more pluses, the better the defense.

SPF refers to the sun protection time, and PA refers to the ability to resist tanning.

What exactly is UVA

UVA has a long wavelength, which can penetrate the epidermis and penetrate into the tissues below the dermis, destroying collagen and elastic fiber tissue, causing wrinkles and sagging, accelerating the formation of melanin, and darkening the complexion. In general, the PA logo on sunscreen indicates the ability to protect against UVA. + The more, the longer the protection.

It can be understood that PA+ is about 4 hours, PA++ is about 8 hours, and PA++ is longer than 8 hours.

The sun protection factor is a specific numerical value that indicates the product's ability to defend against UVB rays, and is a protective index to evaluate the ability of sunscreen products.

The sun protection factor refers to the index of the protection of the sunscreen product against ultraviolet rays in the sun, and this number is used to indicate the level of sunscreen that the sunscreen product can play.

It is the protective effect of your **, and the higher the sun protection factor, the better the protection effect will be.

There are two types of labels on the sunscreen label related to the effectiveness of sun protection, one is the SPF value and the other is the PA rating.

1. SPF value

SPF is a performance indicator of sunscreen protection** against the occurrence of sunburn erythema, and is a measure of the effectiveness of UVB protection, known as the sun protection factor or sun protection factor.

When the measured SPF value of the sunscreen is 2, the sunscreen effect shall not be marked; 2 When the SPF value is 50, the actual value is identified, and the larger the value, the better the protection effect; When the SPF value is 50, the specific value is no longer marked, and it is uniformly marked as 50+.

Sunscreen cosmetics that have not been tested for waterproof performance, or if the results of the waterproof performance measurement of the product show that the SPF value is reduced by more than 50 after bathing, the waterproof effect shall not be claimed. Sunscreen cosmetics that claim to have a waterproof effect can be marked with both the pre-bath and post-bath SPF values, or only the post-bath SPF value, but not only the pre-bath SPF value.

2. PA grade

The SPF value is to evaluate the protective effect of the product against UVB, and the corresponding PFA value reflects the defensive effect of the product against UVA. When the measured PFA value of the sunscreen is 2, the UVA protective effect shall not be marked; 2 When the PFA value is 16, the corresponding PA class can be identified according to its value.

When the UV wavelength absorbed by sunscreen cosmetics is greater than or equal to 370nm, it can indicate a broad-spectrum sunscreen effect. In addition, it should be noted that there is no unified international regulation on the identification of UVA defense effect of sunscreen cosmetics, and countries such as China and Japan use the PA grade identification method, while Europe and the United States and other countries do not use this labeling method.

Sun Protection Precautions:

Do not use it before applying makeup, and do not wear sunscreen before going out. Sunscreen is the same as normal skin care products and takes some time to absorb into the skin, so you should apply sunscreen 10 to 20 minutes before going out and 30 minutes before going to the beach.

The amount of sunscreen used should be sufficient is not effective when applied, but to reach a certain amount to exert the effect of precession, usually sunscreen on the ** when the amount of application is 2 mg per square centimeter, in order to achieve the due sunscreen effect. It is important to note that SPF values cannot be accumulated, and applying two layers of SPF10 sunscreen will only have one layer of SPF10 protection.

The above content reference: National Medical Products Administration - What do SPF and PA stand for?

The sun protection factor (SPF) is a specific numerical value that represents the product's ability to defend against UVB rays, and is a protective index to evaluate the ability of sunscreen cosmetics to protect against sunburn. SPF is the English abbreviation of Sun Protection Factor, the higher the SPF value, the better the protection against sun patches and sunburn.

The sunscreen efficacy of sunscreen cosmetics refers to the ability to protect against ultraviolet rays, which is often expressed by the sun protection index (SPF value) and the sun protection level (PA) on cosmetics labels. The sun protection index of UVA protection is expressed in PA or PPD.

Misunderstanding of sun protection factor:

Myth 1: The higher the SPF value, the better the sunscreen effect.

The sun protection factor is only a reference number, in fact, it must also be considered according to the individual's skin type, sun reaction, color, activity and sweat status.

Myth 2: The whole family should share a sunscreen product.

The choice of sunscreen needs to be "personalized", and family members should choose sunscreen according to their own needs.

Myth 3: **Expensive sunscreen products are more effective***.

The effect of sunscreen products to block ultraviolet rays lies in the sunscreen ingredients and content contained, and there is no absolute relationship with the level of the sunscreen. **High sunscreen may not be suitable for everyone, and should be chosen based on individual skin type, environment and time.

The sun protection factor is also known as the sun protection index. The English abbreviation of Sun Protection Factor 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 time it takes for the lowest erythema to appear in the same sunlight** is prolonged after the use of sunscreen, the SPF of the sunscreen is:

SPF Minimum amount of erythema agent (after sunscreen) Minimum amount of erythema agent (before sunscreen).

Sun exposure will cause photoaging, resulting in dark spots, freckles and so on. Sunscreen products can effectively resist the damage of ultraviolet UVA and UVB. If you want to find out how long sunscreen will protect you, you should first know how long you need to stay in the sun without using sunscreen at all before your ** will turn slightly reddish; Then multiply the required time by the SPF value, which means the protection time of the car sunscreen, in other words, the SPF value marked on the sunscreen is the protection index it provides.

For example, if you spend 20 minutes in the sun without sunscreen and your ** turns slightly red, a SPF 15 product can protect you for up to 5 hours.

20 (minutes) x 15 (SPF) = 300 minutes (5 hours)

It's how many minutes you want to prevent tanning.

No, the higher the sun protection factor, the more harmful the substance inside will do to **.

If it's summer under the scorching sun, it's best to use 244 or 5 to wipe it every 2 hours, you can't just wipe it in the morning and then leave it alone, this is not okay.

No, the index is too high, so that there is a burden on the **, and the damage to the ** is also great, so if you are not outdoors for a long time in summer, you don't need to choose a sunscreen with a high index.

Of course not! SPF should be at least 20, in fact, to achieve the sun protection factor it indicates is to apply very thick and thick, it is recommended that PA should be added to three as well, two or one has almost no effect.

Look at women more, I have the most to say!

The selection method of SPF is relatively simple, and the specific situation is as follows:

1. For people of general type, it is better to choose 8 12 sun protection factor SPF value;

2. For people who are sensitive to light, it is better to choose a sun protection factor SPF value of 12-20;

3. Office workers who are only exposed to the sun on the way to and from work can choose the SPF value below 15 for the sun protection factor, and the sun protection on the face is the main one;

4. When playing in the wild and swimming on the beach, choose a sunscreen SPF value of more than 30, and it is best to choose waterproof sunscreen skin care products when swimming.

5. It is better to choose the SPF value of the sun protection factor for general indoor use at 15-20, the SPF value of the sun protection factor greater than 20 when going out, and the SPF value of the sun protection factor when going to the beach is recommended to be 30.

SPF value and PA value are the two most commonly used sun protection indexes, and SPF value is the protection evaluation for UVB, abbreviation, sun protection factor. The PA value is the protection evaluation for UVA, abbreviation, protection factor. Its degree is indicated by three intensities: + and +, "The more +, the better the effect of preventing UVA."