Cosmetic Sun Protection Factor (SPF)
The SPF value, that is, the sun protection factor, means the time multiple of the skin's resistance to ultraviolet rays. It is calculated like this: the average Caucasian skin can withstand the sun for 5 minutes without being burned, so if you use SPF20 anti-ultraviolet products, you have about 100 minutes of sun protection time.
Objectively speaking, the level of SPF 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 to block ultraviolet rays.
Generally speaking, the SPF of the lowest sunscreen products is SPF2-6, the medium sunscreen product is SPF6-8, the high-end sunscreen product is SPF8-12, and the products with SPF value in the range of 12-20 are high-strength sunscreen products. Products between 20-30 are ultra-high-strength sunscreens.
In the past, the higher the coefficient of sunscreen, the more sticky and airtight the texture and touch, and people with oily skin would avoid it. Well now, although the factor of new sunscreen products is getting higher day by day, most brands have eliminated the greasy defect well, and customers no longer have to worry about airtightness.
How to choose the right SPF value
There are two kinds of sunscreen agents commonly used in sunscreen products that focus on UVA: ultraviolet absorbers and ultraviolet shielding agents (such as ultrafine powders of Titanium Dioxide and Zinc Oxide). Actually it is impossible for a product with an SPF of 20+ to not contain Titanium Dioxide.
While sunscreen absorbs ultraviolet rays, it has a certain stimulating effect on the skin. If the ultraviolet absorber is excessive, it will also become a burden on the skin. Therefore, we should not blindly pursue products with high SPF values, but should determine them according to our occupation and specific use environment.
1. For people with normal skin type, the SPF value should be 8-12;
2. For people who are sensitive to light, the SPF value should be 12-20;
3. For sensitive skin, you should choose plant-based sunscreens or sun oils containing titanium dioxide. You can also use products containing vitamin E and preservative-free products. Vitamin E has a high anti-sun effect, and it has lubricating ingredients and purifying effects, which can neutralize cell damage caused by sun exposure.
4. When using fruit acid skin care products, it should be used with physical sunscreen products with a high sun protection factor to prevent the newborn skin from being damaged. Because fruit acid skin care products will make the skin thinner, more fragile, and not resistant to ultraviolet rays.
5. For office workers who only come into contact with the sun on the way to and from get off work, the SPF value below 15 will be just fine, mainly focus on facial sun protection; in addition, fair-skinned people had better choose sunscreen products with SPF over 30 to prevent spots. The guys with darker skin can use sunscreen with SPF 15 on weekdays.
6. In the season when the ultraviolet radiation is stronger, the SPF value of the selected sunscreen should be higher.
7. When playing in the wild or swimming in the sea, the human skin is completely exposed to the sun, and the SPF value of the sunscreen should be above 30. It is best to choose waterproof sunscreen skin care products when swimming, but these products are mostly water-in-oil emulsified and should not be used more often.
Post time: Sep-14-2023