What is Spf? How much sunscreen is good for Spf 50, Spf 30 or Spf 15?

SPF is an important indicator of sunscreen - an indispensable cosmetic in the care and protection of the skin of both women and men. So, what is SPF? What does it mean? This article will help you answer that question.

What is the SPF?

The full name SPF is the Sun protection factor, according to the FDA, a measure of the UVB protection used in sunscreens. This index is calculated by the number of hours and percentage of UV protection when using sunscreen on the skin.

The lowest SPF is 15 and the highest is 100. According to studies, 1 SPF will be able to protect the skin and limit the harmful effects of UVB rays in about 10 minutes.

You can understand the meaning of SPF on sunscreen in two ways:

1. Understand the time of UV protection: That is, take the SPF multiplied by 10 to calculate the time to protect the skin, against the harmful effects of UVB rays in minutes. For example, a sunscreen with an SPF of 30, the time to protect the skin from the harmful effects of UVB rays is 300 minutes.
2. Understand the percentage against UV rays: If put in perfect condition, sunscreen with SPF of 15 will block about 93.4% of harmful effects from UVB rays, SPF 30 is about 96.7%, SPF 50 is about 98%. However, this rate is only relative in a certain time.

Sun protection index how much is good?

Most people will think that the higher the SPF, the better the sun's ability to protect against UV rays. However, the fact that this concept is not entirely true. The reason is because:

1. Sunscreens with high SPF are not necessarily suitable for the skin of users
2. Sunscreens with high SPF tend to focus more on UVB protection than UVA protection.
3. The duration of sun protection of sunscreens with an SPF of over 60 is no more than the SPF 50. But if you use a high-SPF type for a long time will easily cause the phenomenon of clogged pores and skin damage. This is also a cause of signs of aging for the skin.

So in fact, how much sunscreen is a good sunscreen?

Dermatologists recommend that we use sunscreens with an SPF of 30 to SPF 60.

Sunscreens with an SPF of less than 30 will not work as expected. However, if your skin condition is inflamed and inflamed acne, you should only use sunscreens with an index of 15-30 to avoid skin irritation.

For creams with a high index of 60-100, it should be used only in special skin areas to avoid the sun such as the skin being treated for melasma or allergy to sunlight.

A few notes when choosing to buy sunscreen

When choosing to buy sunscreen, besides SPF, you should also pay attention to some of the following factors:

Should choose broad spectrum sunscreen (Broad spectrum)

As you know, UVB is the cause of dark skin and is also the cause of skin cancer. And UVA, while not causing sunburn, penetrating deeply into the skin leading to aging including wrinkles, age spots or sagging condition . For this reason, when choosing sunscreen you Be sure to choose a cream that can protect against both effects from UVA and UVB rays. Often these creams are called broad-spectrum sunscreens and often have the words Broad Spectrum or Broad spectrum UVA / UVB.

Concerned about the water resistance of the cream

Most people often use sunscreen when going to the beach, going out, so the water resistance of the cream is also a factor that you should consider when choosing. The waterproof cream is not only suitable for swimming, but on hot summer days it is also great for those who sweat regularly. However, not drifting does not mean waterproof, they will only be able to protect your skin from 40-80 underwater.

Avoid some of the ingredients below

Sunscreen will have a lot of chemical components, you should know and avoid the chemicals that cause negative effects to the skin such as:

1. Oxybenzone: This ingredient has a great effect of absorbing ultraviolet rays, but many studies show that they absorb ultraviolet rays through . skin and blood. They can break down hormones, damage cells and lead to skin cancer.
2. Retinyl palmitate: Research done on animals shows that this substance may increase the risk of skin cancer when they are exposed to direct sunlight.
3. Paraben: This is the most widely used preservative in cosmetic products. Parabens may act similarly to estrogen estrogen - one of the main causes of breast cancer. Although the chemical has not been published in its association as a contributing factor to cancer, be sure not to choose creams that contain this ingredient.

Choose creams with clear origins

The sunscreen market is quite diverse and complex. So, choose for yourself a brand of sunscreen reputation, which is recommended by many users as well as experts.

Where should i buy sunscreen?

To buy quality sunscreen products, make sure you can visit the website: META.vn or directly through the address below for more detailed advice:

1. Hanoi: 56 Duy Tan - Dich Vong Hau - Cau Giay. Hotline: 024.3568.6969
2. Ho Chi Minh City: 716-718 Dien Bien Phu - Ward 10 - District 10. Hotline: 028.3833.3366