When and how often should you apply sunscreen?

Sunscreen is also a skin care product that many people like to use. It can protect your skin from external harm. When should you apply sunscreen? How often should you apply sunscreen?

When to apply sunscreen

Sunscreen can be applied half an hour before going out, once around 12 noon, once every 2 hours when working outdoors, once every 2 hours when traveling on vacation to the beach, and also before and after swimming.

When to apply sunscreen

1. Apply half an hour before going out

Sunscreen, like other skin care products, takes a certain amount of time to take effect after being applied to the skin. Therefore, when going out, it is best to apply it half an hour in advance. Before applying sunscreen, don't forget to clean your skin and apply skin care products such as toner, lotion and cream to protect your skin.

2. Apply once around 12 noon

Sunscreen can generally last for about 6-8 hours after being applied once, but human skin will secrete different amounts of oil and sweat depending on the environment. When too much oil and sweat are secreted, it will affect the duration of the sunscreen, and people will wipe off some of the sunscreen when wiping their faces. Therefore, after applying it once in the morning, it is recommended to reapply it around 12 noon. Of course, this situation is only limited to indoor workers and people who are not often exposed to the sun.

3. Apply once every 2 hours when working outdoors

For some people who need to stay outdoors for a long time due to work, it is best to apply sunscreen every 2 hours. Because these people are exposed to ultraviolet rays for a long time, the sun protection effect of sunscreen will gradually decrease after absorbing ultraviolet rays, and eventually lose its sun protection effect completely.

4. Apply the paint every 2 hours during a seaside vacation

The ultraviolet rays at the seaside are stronger than those in the city, and there are fewer obstructions at the seaside, so the ultraviolet rays can directly shine on the skin. Therefore, it is even more necessary to do a good job of sun protection. It is recommended to reapply sunscreen once every 2 hours. If you exercise vigorously and sweat a lot, you can even apply it once an hour, because sweat can easily dilute the sunscreen and shorten the duration of the sunscreen. Remember that the stronger the UV rays, the shorter the duration of sunscreen.

5. Apply before and after swimming

Although most sunscreens are now waterproof, the water in the pool will still wash away some of the sunscreen ingredients after you actually get into the water, thereby reducing the sun protection effect and shortening the protection duration. This is especially true when swimming outdoors, where the sun can directly shine on the skin. If you don't apply sunscreen before swimming, it is very likely to cause tanning and sunburn. Therefore, you need to apply it before and after swimming.

How often should you apply sunscreen?

1. Reapply sunscreen every 4-5 hours

How often you apply sunscreen depends on your personal environment. If you work indoors and are basically not exposed to the sun, you can reapply it every 4-5 hours. That is, apply it once in the morning when you go out and once at noon. It is enough to apply it twice a day. Because you are not exposed to the sun, the sunscreen lasts longer.

2. Reapply sunscreen every 2-3 hours

In addition to indoor workers, there are outdoor workers, such as couriers, salesmen, and deliverymen, who often need to work outdoors in the sun. It is recommended to reapply sunscreen every 2-3 hours, because the ultraviolet rays outdoors are much stronger than those indoors, and the stronger the ultraviolet rays, the faster the sunscreen will become ineffective.

3. Reapply sunscreen every 1-2 hours

The intensity of outdoor ultraviolet rays varies in different regions. If you go to tropical areas, or areas with strong ultraviolet rays, such as the seaside, you need to reapply every 1-2 hours. The stronger the ultraviolet rays, the faster the sunscreen will become ineffective. At the same time, the temperature is high in places with strong ultraviolet rays, and the skin sweats and produces more oil, which easily dilutes the sunscreen. Therefore, you need to reapply more frequently. If you go swimming, it is best to reapply after swimming.

4. Different sun protection indexes have different intervals

In addition to environmental factors, reapplication of sunscreen is also related to the sun protection factor. The sun protection factor, or SPF, refers to the ability of sunscreen products to defend against ultraviolet UVB. Usually we multiply the sun protection factor by 20, and the resulting number represents the sun protection time that the sunscreen product can last. For example, for a sunscreen lotion with SPF20, multiplied by 20 is 400 minutes, and for a sunscreen lotion with SPF50, multiplied by 20 is 1000 minutes.

This is the introduction to the time to apply sunscreen. Pay attention to the time to reapply.