There’s a reason dermatologists wax lyrical about sunscreen. It is probably the most effective skincare product in the fight against sun damage, melanoma and premature ageing.
But do you really know what to look for in a sunscreen? Chances are, if you’ve ever been sunburnt or feel greasy or sticky, you need to look for something new. Something that’s going to protect you from both the harmful UVB and ageing UVA rays so that your skin is protected for hours on end, without clogging pores or leaving a greasy film on your skin.
So what is the difference between UVA and UVB rays? UVA rays account for up to 95 per cent of the UV radiation reaching the earth’s surface, and can penetrate clouds and glass. These UVA rays are the ones linked to photo-ageing like hyperpigmentation, fine lines and wrinkles, loss of collagen and elastin, and a change in skin tone.
UVB rays are the rays that burn you. They too can lead to premature ageing and both UVA and UVB rays have the potential to cause skin cancer. Bottom line: you need to protect your skin against them both.
While the Sun Protection Factor (SPF) is a good gauge of how effective your sunscreen is in protecting your skin against UV rays, it only measures the amount of UVB radiation transmitted to the skin before and after sunscreen. So, an SPF 50 simply means that sunscreen is giving your skin 50 times more protection from UVB rays than if you weren't wearing anything at all. This is great, but what about UVA rays?
Enter stage left: complete UVAUVB sunscreen ingredients. Broad-spectrum is a measurement of a sunscreen's effectiveness against UVA rays and it's these sunscreens that guard your skin against both types of UV radiation. In order to be deemed broad-spectrum, a sunscreen needs to absorb 90% of UVA and UVB rays up to a critical wavelength of UV radiation, but may not cover the entire UVAUVB spectrum.