The hot summer is about over, but keeping ourselves from being burned can’t be slacked. We should be thinking about SPF all year round no matter if it’s cloudy weather or rainy day, in summer or winter.
When it comes to sun protection, we need to know what the sunscreen is actually preventing from the sunlight. The infrared rays of the sun give us warmth, visible light gives light, and UV rays are the most important factor causing photoaging of the skin. Ultraviolet rays are divided into UVA ( wavelength: 320 to 400 nm), UVB ( wavelength 275 to 320 nm), and UVC (wavelength 200 to 275 nm). Short-wave UVC, before reaching the ground, is absorbed by the ozone layer, so its effect on the skin is negligible. UVB is the ultraviolet ray that causes sunburn, which acts on the epidermis of the skin and can cause pigmentation and skin roughness. UVA penetration is extremely strong and can be deep into the basal and dermal layers of the skin, which is the main cause of skin tanning.
Some people think that the sun is hidden by clouds and there is nothing that will hurt your skin. Dear, I’m afraid that nothing could be more wrong than this opinion. Clouds can block infrared rays, but ultraviolet rays in sunlight still exist even on a rainy day. UVA ultraviolet ray on a rainy day is 10% of clear days, and on a cloudy day is 50%-60% of clear days.
Now we know a little something about the reason for skin burning and tanning. But how much do we really know about sunscreen? What does SPF 50 mean? Does a higher SPF mean better protection?
What does SPF 50 mean?
The SPF of a product is related only to its protection against UVB or "burning" rays. The higher the SPF level, the good the protection against UVB or “burning” rays. An SPF 50 product protects you from 98% of the UVB “burning” rays that penetrate your skin. This means in the afternoon on a clear day, especially in summer, remember to apply this type of sunscreen to protect your skin.
Maybe you wonder that seems the highest SPF is 50, does there have any product that is higher than SPF 50?
Since SPF 50 protects against 98% of UVB rays and nothing provides 100% protection, there is no statistical significance to using SPF values above 50. products with higher SPF values may be misleading and give consumers a false sense of security. If the product is marked SPF 100, some customers will think that this sunscreen offers 100% protection from UVB rays, or the product works all day. But it’s impossible.
The market also provides SPF 30 and SPF 15 products, how to choose them?
A SPF 15 product prevents 93% of UVB rays and a SPF 30 product prevents 97%. There is a considerable difference between SPF 15 and 30, but between SPF 30 and SPF 50, the difference in coverage is greatly reduced. SPF 15 products are suitable for indoor use. If you are going shopping or going to work, then choose SPF 30 products. If you are going to an event that will be exposed to the sun for a long time, SPF 50 products are the best choice.