Try reading about sunscreens and it is easy to become overwhelmed. Which sunscreen is the right one to use and what is the right way to use it?
Basically, this is what you need to know.
Wear a broad spectrum sunscreen with at least an SPF of 30, and reapply every two hours while outside and after swimming, regardless of whether or not it says it is water resistant.
SPF stands for sun protective factor and is the measuring tool that tells us how much blocking power the sunscreen we have chosen has.
Apply the sunscreen 15 minutes before going outside.
“That allows it to bind to the stratum corneum, the outer layer of the skin,” said Dr. John Wolf, chairman of the Department of Dermatology at the Baylor College of Medicine, in an REI.com sunscreen article.
Use a nickel-sized dose for your face alone and apply roughly an ounce in total to the entire body — about a shot glass full. Wolf suggested slathering it on to make sure you use enough. Don’t forget your ears and the tops of your feet.
Do not make the mistake of thinking that SPF 50 is almost twice as strong as SPF 30.
This is how SPF really works:
- An SPF of 15 blocks 93 percent of UVB rays
- An SPF of 30 blocks 97 percent of UVB rays
- An SPF of 50 blocks 98 percent of UVB rays
- An SPF of 50+ blocks 99 percent of UVB rays
You need to choose a broad spectrum sunscreen so it blocks both UVA and UVB rays.
It used to be that sunscreens just focused on UVB rays. UVB rays are the ones that only penetrate the skin's outer layers but can cause sunburn and blistering. UVB cannot penetrate glass.
However, UVA rays have longer wavelengths, penetrate deeper into the skin, and are thought to be the main contributors to sun-induced aging. UVA rays can penetrate glass.
Both UVA and UVB have been found to contribute to skin cancers including melanoma, according to Skincancer.org.
Sunscreens no longer can be labeled waterproof or sweat proof, only water resistant according to the new FDA guidelines.