Sunscreen is the last step in your day-time routine.
Who doesn't like a sunny day? However not everybody is aware of the harm the sun can bring to our skin. The sun emits ultraviolet(UV) radiation and there are two types of them: UVA and UVB. UVB damanges the outer layer of our skin whereas UVA penetrates more deeply. let's take a look at what they could do to our skin:
Skin cancer (UVA/UVB)
Speed up aging process (UVA)
Darken scars/pigmentation (UVA)
Uneven skintone (UVA)
Skin damage from sunburn (UVB)
How does sun screen protect you from uv rays?
Sunscreens block off or absorb the UV rays so that they don't reach your skin cells. However sunscreens are broken down by the sun gradually over time, which is why it is important to reapply them every few hours.
SPF, also known as the Sun Protection Factor indicated on the sunscreen product packaging, tells you how long it would take for UVB to start reddening your skin with the sunscreen applied compared to when it's not. For instance, a SPF 50 would mean it takes the sun 50 times longer to burn your skin. In general, it takes 10 to 20 minutes for bare skin to start burning, with a SPF 50, it would take 500 to 1000 minutes.
PA, short for Protection Grade of UVA, also indicated on the sunscreen product packaging, tells you how much protection the suncreen has against UVA. The more +, the more protection it can offer.
To effectively shield your skin from both aging and burning, use a sunscreen that offers both UVA and UVB protection.
when to use sunscreen?
Most people only apply sunscreen when they are going to the beach on a sunny day and they think they are safe from the UV rays indoors or on a cloudy day. However, UVA rays can actually penetrate windowpanes and clouds, making it more dangerous as people tend to ignore the invisible danger. Certain indoor lighting also emits UV rays, for example fluorescent lights. Making sure you apply sunscreen everyday regardless of the weather and location is important.
After application, sunscreen takes 15-20 minutes to form a protective layer on your skin to be effective. This is why you should leave some time between application and going outside.
What type of sunscreen?
There are two types of sunscreen: physical and chemical. They both offer protection for the skin from the UV rays but in different ways.
Physical sunscreen, also known as mineral sunscreen, protects skin by blocking and reflecting the UV rays before it penetrates. Main ingredients for a physical sunscreen include titanium dioxide and zinc oxide. These mineral actives are white powers, which is why physical sunscreens usually leave a visible white cast on the skin.
Chemical sunscreen absorbs the UV rays to protect the skin. Most common ingredients are avobenzone and octisalate. Chemical sunscreens do not need to have high concentration of these ingredients to be effective, hence they are more light-weight and do not leave a white cast.
There are hybrid sunscreens which contains both types of ingredients to maximise the effect and minimise the drawbacks.