Things to know when using sunscreen

1. What is sunscreen?

Sunscreen is a product formulated as a spray, gel, or cream... containing physical or chemical ingredients that can block, absorb, or disperse some UV radiation on the skin exposed to sunlight, to limit sunburn, skin aging, or skin cancer.

UV radiation is made up of three types of rays - ultraviolet A (UVA), ultraviolet B (UVB) and ultraviolet C (UVC). Of these, UVC is the most dangerous, but it cannot penetrate the ozone layer of the atmosphere, so it does not harm the earth. The remaining 95% are UVA rays and 5% are UVB rays.

UVB affects the outer layer of the skin, causing skin damage, sunburn, and can lead to several types of skin cancer such as melanoma, basal cell carcinoma, and squamous cell carcinoma.

UVA rays can penetrate deeper layers of the skin and cause more damage than UVB rays. UVA rays can penetrate thin materials such as glass, clothing, clouds, etc., so even if it is cloudy or you are wearing sunscreen, your skin is still severely affected. UVA does not cause skin darkening like UVB, but it causes skin aging and immune suppression. In addition, it also affects the basal cell layer of the epidermis, where most skin cancers occur.

Therefore, sunscreen products were born with the aim of preventing cancer by protecting the skin from dangerous ultraviolet rays. In addition, sunscreen also helps prevent aging, melasma, freckles, etc.

2. How to use sunscreen?

Everyone, including children and teenagers, should wear sunscreen. Sunscreen should be applied during the day, even when it feels cloudy.

Apply sunscreen at least 15 minutes before going out.

Reapply every 2-5 hours, depending on the type of sunscreen used. If you wear makeup, use a spray or powder sunscreen to supplement the next application of sunscreen.

Protect your lips by applying lip balm with sunscreen.

When applying sunscreen, don't be too "economical" but apply a thick enough layer to cover the entire surface of the face, neck and exposed skin areas directly exposed to sunlight.

For those who often wear makeup, although makeup products such as foundation contain sunscreen, it is not enough to protect the skin from UV rays. Moreover, the moisturizer underneath creates a layer that prevents sunscreen ingredients from penetrating the skin. Therefore, you should apply sunscreen before applying makeup, or choose a daytime moisturizer with sunscreen.

Choose a sunscreen with an SPF of 30 or higher to protect against UVB rays (which cause sunburn and darkening of the skin) and PA to protect against UVA rays (which cause skin aging).

PA is a way to evaluate the level of UVA protection. The plus sign after PA determines the level of UVA protection of the product. For example, PA+++ means that the product has high UVA protection.

Use separate facial sunscreen and body sunscreen. Using body sunscreen on the face will make the skin very stuffy, oily and prone to acne because body sunscreen is often very oily.

For office workers who rarely go outside, sunscreen is still essential, because UV rays can penetrate through glass, causing melasma, freckles, wrinkles, and aging.

Avoid applying sunscreen to mucous membranes because some sunscreens can cause irritation if they come into contact with mucous membranes such as the eyes, mouth, etc.