Is it okay to apply 50x sunscreen once a day? How often should I reapply 50x sunscreen?

When using SPF50 sunscreen, it means that the sun protection time can be extended 50 times, that is, the skin will not turn red until 1000 minutes later. So, is it okay to apply 50x sunscreen once a day?

Is it OK to apply 50x sunscreen once a day?

Can't. Theoretically, 50 times the sun protection lasts for a long time, but the sun protection strength is still affected by the thickness of the sunscreen applied, sweating and oiliness on the face, etc. Therefore, it is better to apply 50 times the sunscreen at least twice a day.

How often should I reapply 50x sunscreen?

If you are constantly outdoors in the sun, you need to reapply sunscreen every two hours; if you are only outdoors occasionally, you can reapply every three to four hours. 50x sunscreen has a long protection time and better ability to protect against ultraviolet rays, making it very suitable for people who go to the beach to play or sunbathe.

50 times the sun protection time of sunscreen

One SPF value is equivalent to 10 to 15 minutes of sun protection time. So, 50 times is ~

50 (SPF) * 10 (minutes) = 500 minutes = 8.3 hours

50 (SPF) * 15 (minutes) = 750 minutes = 12.5 hours

That is to say, if you apply 50x sunscreen once, you will have to wait 8.3 to 12.5 hours before applying it again. In other words, after applying it once before going out, you don't need to reapply sunscreen.

Is it necessary to use 50x sunscreen?

It is still necessary. Generally, when you go to the beach or seaside, or do outdoor work or activities, it usually takes more than ten hours. At this time, not only is the direct ultraviolet radiation relatively strong, but the skin is also exposed to ultraviolet radiation for a long time, up to more than ten hours. Therefore, it is recommended to use 50 times sunscreen when doing outdoor sports or outdoor work, otherwise the SPF is too low to achieve effective sun protection.