Sunscreen: it’s a must have for anyone who likes being in the sun and doesn’t like getting burned, wrinkling early in life, or risking skin cancer. It’s something you probably use all the time (and if you don’t, you should!), but very few of us actually know all that much about it.
Vine Vera has gone over the history of sunscreen and how it developed since the ancient Greeks first started putting olive oil on their skin to keep from getting burnt (but remember, they didn’t know as much about Ultraviolet radiation as we do now, so make sure you use actual sunscreen when you go out), but here we will be taking an in-depth look at how modern-day sunscreens work, and what you need to know to get the most out of them.
To examine how sunscreen works and what it does to protect us, we first have to examine what it is about the sun that threatens our skin in the first place. The sun is necessary for life to exist on our planet, and provides warmth, light, and a source of energy to plants, the lowest and arguably most important part of the food chain.
But as necessary and beneficial as the sun is, there is a dark side to the energy it provides us. Sunlight contains a wide spectrum of light waves, most of them totally harmless, but a particular completely invisible type of light known as Ultraviolet (UV for short, split into two types: UVA and UVB), which can actually penetrate skin cells and damage their DNA, triggering severe defensive mechanisms by the cell. The redness of a sunburn isn’t actually directly caused by the UV radiation itself, but is a result of increased blood flow to the area while cells try to fix the damaged DNA, and peeling is a result of the body’s attempt to get rid of skin cells too badly damaged to fix. Regardless, this DNA damage, while usually repairable by your body’s immune system, is not always repaired perfectly, and can occasionally lead to the development of skin tumors, which is why sun exposure increases your risk of melanoma.
So, how do sunscreens stop harmful UV rays from entering your cells and messing with your DNA? There are a few ways, but—as Vine Vera has explained before—they can all be roughly divided into chemical and physical sunscreens.
Chemical sunscreens contain compounds that produce a chemical reaction when UV light hits them. This reaction turns UV light into other types of energy, which are harmless to your skin, so your skin is saved by your sunscreen giving the UV light something else to react with instead of your DNA.
Physical blockers are a little more straightforward. They’re minerals ground into a soft powder that UV light is simply unable to penetrate, so if you coat your skin with physical-blocker sunscreen, UV light just bounces right off of you.
All of this may be interesting and help you better understand why and how to use sunscreen, but what essential details do you need to know to protect your skin?
That’s actually pretty simple. Sunscreens are graded on a scale called “SPF” for “Sun protection factor,” and all you need to know is that you need SPF 30 or higher to really be protected, you should reapply every couple hours, make sure your sunscreen protects from both UVA and UVB, and if you’re unable to reapply every couple hours (although you really should) for whatever reason, get a sunscreen with physical blockers, since these are more durable. Look for the ingredients “titanium dioxide” and “zinc oxide” and you’ll know you’ve got a physical-blocker sunscreen.