How Much Do You Know About Sunscreen?
Although it may seem as though you need a PhD in chemistry to choose sunscreen today, knowing just a few simple facts will make selecting the right sun protection much easier.
The fundamentals of sun protection are straightforward: the sun emits ultra-violet rays, UVA, UVB and UVC. UVA rays, the longest, are now known to be mostly responsible for sun-related aging and many skin cancers. UVB rays are the ones that tan (or burn) your skin. UVC rays would kill you, but they are blocked by the ozone layer (another reason to be concerned about carbon emissions degrading the ozone layer).
The SPF value is a measure of a sunscreen’s efficacy against UVB rays, and UVB rays only — the higher the SPF, the more protection it offers.
“Broad spectrum” means that the sunscreen contains ingredients to block UVA rays as well as UVB. Only a handful of minerals (zinc oxide and titanium dioxide), which reflect the rays, and chemicals (ecamsule, avobenzone, dioxybenzone), which absorb the rays, have been shown to be effective against UVA rays.
The irony of many of the chemical sunscreen ingredients is that they are photo-unstable, which means they degrade and lose efficacy when exposed to sunlight. Although recent innovations have produced more photo-stable UVA blockers by combining them with other ingredients such as octocrylene, oxybenzone and octinoxate, these chemicals have also been found to have significant safety concerns.
Read the label when choosing your sunscreen and look for products that DON’T contain oxybenzone or octinoxate but DO contain mexoryl, ecamsule, avobenzone, zinc oxide or titanium dioxide.
The Environmental Working Group published an exhaustive report on sunscreens that reviews them for effectiveness and safety and can be searched for specific brands or ingredients. It’s online here.
For more information, visit these resources: