Things We Need to Know About Sunscreen

The most important daily rule for maintaining young and healthy skin is using sunscreen. It is recommended that everyone, regardless of age, gender, season, time of day, or weather, use sunscreen. The key indicators to check when choosing a sunscreen are SPF and PA. SPF, the sun protection factor, indicates the effectiveness of blocking UV-B rays. For Asians, multiplying the SPF value by 15 to 20 represents the effective duration of skin protection against sunburn. In other words, SPF 30 means that for Koreans, it provides UV protection for approximately 450 to 600 minutes, or 7 hours and 30 to 10 hours. Therefore, the higher the SPF, the later it takes for sunburn to occur, meaning you can safely enjoy the sun for an extended period.

However, in reality, it must be reapplied every 2 to 3 hours because after 2 hours, almost all of it is washed away by sweat, sebum, and external wind, leaving almost zero on the skin.

In particular, it has been reported that the UV protection effect is further enhanced when reapplied 20 minutes after the initial application.

UV-A protection is indicated by PA, which is classified by grade rather than a numerical value. The more plus signs there are, the higher the UV-A blocking effect. For daily use, SPF 20–30 and PA++ are recommended, while SPF 50 and PA+++ are suitable for outdoor summer activities. If going swimming, be sure to check if the product is waterproof.