Sunscreen! SPF? PA? What do they mean?

Since the purpose of sunscreen is to block ultraviolet rays, we should examine how effectively it blocks them, right? In sunscreen, SPF indicates the blockage of UVB rays, while PA indicates the blockage of UVA rays. You can consider that the higher the respective index, the better it blocks UV rays.

While UVB rays are blocked by glass windows, UVA rays penetrate them, meaning you can be affected even indoors. They reach the deep dermis layer of the skin and cause skin aging, such as wrinkles. Therefore, it is highly recommended that those who spend a lot of time indoors apply sunscreen that blocks UVA rays.

if For those who spend a lot of time outdoors, the SPF index is a measure of UVB ultraviolet protection. You need to look at it carefully. Generally, an SPF of around 15 is considered sufficient for those who mainly engage in indoor activities, while those who spend a lot of time outdoors should use an SPF of 30 or higher. They say it is good to do it.

The PA index, which blocks UVA ultraviolet rays, uses a '+' symbol instead of a number. It is generally considered that the more '+'s there are, the better the blocking is. There are a total of four levels: +, ++, +++, and ++++. PA+ is sufficient for typical daily life, but PA+++ or higher is recommended for those who frequently engage in outdoor activities. They say they will.


Source https://post.naver.com/viewer/postView.naver?volumeNo=32342155&memberNo=54067778