How often should I apply sunscreen? How long does it take for sunscreen to form a film?

When summer comes, sunscreen is a must-have when going out. I heard that sunscreen is only effective for 4 hours. Is this true? How often should you apply sunscreen? Do I need to carry sunscreen with me?

How often should you reapply sunscreen?

Sunscreen should generally be applied every 3-4 hours, and the specific application period can be determined based on different sun protection needs. For sun protection in the office, use SP15PA+ sunscreen and reapply it every 4-5 hours; for sun protection in outdoor sports, use SPF25-30PA+ sunscreen and reapply it every 3-4 hours; for sun protection in swimming, use SPF30PA+++ or above and reapply it every 1-2 hours.

Do I need to carry sunscreen with me?

Sunscreen is a restricted item. Sunscreen or sunscreen spray exceeding 100ml cannot be repacked on site and cannot be brought on board the aircraft.

1. Regulations on international and regional flights

1. Liquid items should be placed in a single container with a volume not exceeding 100ml and carried with you;

2. Containers for liquid items should be placed in resealable transparent plastic bags with a maximum container size of no more than 1L;

3. Each passenger is only allowed to carry one transparent plastic bag at a time;

4. The excess liquids should be checked in as luggage.

2. Domestic flights

Liquid items are not allowed to be carried on board (except for cosmetics, toothpaste and shaving cream for personal use during air travel).

How long does it take for sunscreen to form a film?

The general time it takes for sunscreen to form a film is about 3-10 minutes, and the longest is no more than 10 minutes. After applying sunscreen, sprinkle water on your skin. If you see water droplets forming on the skin, it means that a film has formed. In order to ensure the film-forming effect, sunscreen should be applied half an hour before going out.

Do I need to apply sunscreen every day?

Sunscreen actually needs to be applied every day, because one of the biggest functions of sunscreen is to protect the skin from damage caused by ultraviolet rays, and ultraviolet rays are not only present in summer or when the sun is out. In fact, there is still ultraviolet light in winter or on cloudy days, and ultraviolet light can cause great damage to the skin.