Sun Cream SPF·PA Levels: What Criteria Should You Use to Choose One?

In summer, when temperatures rise and sunlight becomes stronger, sunscreen becomes an essential item before going out. But when choosing sunscreen, terms like SPF and PA ratings can make you hesitate.

Since it is a product applied to the skin, it should be chosen carefully, but it can be hard to know what criteria to use. A higher number is not simply better, and it can vary depending on your skin condition and activity level. Today, let’s look at the information you need to know when choosing sunscreen.

Why should ultraviolet rays be blocked?

Ultraviolet rays are invisible light with short wavelengths and are one of the main causes of skin aging and damage. UV rays are divided into three types: UVA, UVB, and UVC. Of these, the main UV rays that reach the earth’s surface are UVA and UVB. UVA has a longer wavelength and penetrates into the dermis, causing photoaging such as wrinkles, pigmentation, and reduced elasticity. UVB, on the other hand, has a shorter wavelength and affects the epidermis, which can cause acute damage such as redness and burns.

What do sunscreen SPF·PA levels mean?

The SPF and PA values you often see when choosing sunscreen are indicators that quantify UV protection ability. SPF mainly refers to UVB protection, and the higher the number, the longer it delays sunburn caused by UV exposure. SPF 30 is a theoretical standard meaning it can extend the time it takes for redness to appear on the skin after UV exposure by about 30 times.

PA indicates UVA protection and is shown with plus signs. It ranges from PA+ to PA++++, and the more plus signs there are, the higher the UVA protection effect tends to be. For everyday use, SPF 15–30 and around PA++ is sufficient, and for outdoor activities or when you need to stay outside for a long time, products with SPF 50 and PA+++ or higher may be suitable.

Mineral sunscreen? Chemical sunscreen?

Sunscreen is broadly divided into mineral sunscreen and chemical sunscreen depending on how it blocks UV rays. Mineral sunscreen works by using mineral ingredients such as titanium dioxide and zinc oxide to form a layer on the skin that reflects or scatters UV rays. It tends to be less irritating, and because it provides UV protection immediately after application, it is often suitable for sensitive skin. However, it is prone to leaving a white cast and may feel less smooth to apply.

Chemical sunscreen works by absorbing UV rays and converting them into heat energy before releasing it. The formula is lightweight, absorbs quickly, feels less sticky, and is good to use before makeup, but some ingredients can irritate the skin, so caution is needed for sensitive skin.

Sunscreen is not just a product used in summer; it is an essential skincare product for maintaining skin health.

The important thing is not to ask, “Which product is good?” but rather, “Which product is right for me?” If you choose sunscreen by considering your daily routine and skin condition, such as whether your skin is sensitive, whether you are highly active, or whether you wear makeup, it may help you maintain healthier skin.