🌞 Skin barrier part 2: SPF, PA level and how to use sunscreen correctly

Understand the difference between SPF and PA levels, and learn how Korean skincare recommends sun protection.

1. What are ultraviolet rays (UV)?

Ultraviolet rays are electromagnetic waves with a shorter wavelength than visible light and longer than X-rays. UV rays are a natural part of sunlight and play a role in both health and skin aging. In Korean skincare, UV protection is a cornerstone of skin barrier care and anti-aging.

2. Effects of ultraviolet rays on the skin

Prolonged exposure to UV rays can cause:

• Photoaging (premature aging of the skin)

• Wrinkles and age spots

• Skin cancer

• Cataracts and retinal damage

• Weaker immune system in the skin

▪️ SPF (Sun Protection Factor)

Sun protection factor and SPF mean the same thing. SPF is an abbreviation for Sun Protection Factor. SPF is primarily based on UVB blocking ability, with higher SPF numbers providing greater protection.

▪️ PA level

PA is a UV protection rating that can block UV A, and it is recommended to use products with a PA++++ rating for outdoor activities.

3.What is the difference between physical and chemical sunscreen?

▪️ Physical filter

It reflects or scatters ultraviolet rays and prevents them from reaching the skin. It provides immediate UV protection as soon as you apply it. The sunscreen ingredient is not absorbed into the skin and remains on the skin surface, making it safe even for sensitive skin. Because it is a heavy consistency, it does not spread well and can leave a white coating on the skin.

Because it is a heavy formulation, it spreads poorly and can cause a white hazy effect on the skin.

▪️ Chemical filter

It absorbs ultraviolet rays and converts them into heat, preventing them from reaching the skin. It has no white cast and is transparent, so it spreads easily and gives a natural skin tone, but it can irritate sensitive skin. UV protection does not last and must be reapplied every two hours.

▪️ Combination of physical and chemical filter

This product is made by blending the benefits of inorganic and organic tea evenly, reducing white coating on the skin and immediately showing the blocking effect. The mixture of various ingredients may be irritating to sensitive skin.

4. How to use sunscreen correctly

▪️ Adults should apply approximately 30 g of sunscreen evenly over the face, neck, arms and legs.

▪️ After being in the water or sweating, you must reapply sunscreen every two hours to maintain its effectiveness.

▪️ It is recommended to apply sunscreen 15 minutes before going outside.

▪️ It is recommended to choose a sunscreen that can block both UVA and UVB rays.

▪️ During strong sunlight, use a product with a high SPF index.

Using sunscreen is very important to keep your skin healthy. Sunscreen should always be applied regardless of the weather. This is because ultraviolet rays reach the ground regardless of the season and cause skin damage.