We’re in the heart of the summertime and when people are outside and uncovered, they need sunscreen (you also need it indoors and all year long–see below). There are a few things to consider when it comes to your skin, exposure to the sun, and sunscreen.
You probably know that sunscreens are products combining several ingredients that help prevent the sun’s ultraviolet (UV) radiation from reaching the skin. You might not know that there are two types of ultraviolet radiation, UVA and UVB, that damage the skin, age it prematurely, and increase your risk of skin cancer and skin damage.
What is Ultraviolet Radiation?
Not everything shining from the sun reaches the earth. With shorter wavelengths than visible light, UV radiation is the invisible part of the sunlight that reaches the earth from the sun. UVA and UVB represent different wavelengths of light. There is a UVC, but it is blocked by the ozone layer and doesn’t reach the surface of the earth.
According to the Skin Cancer Foundation (SCF), UVB is associated with sunburn and skin cancer risk, and UVA causes the skin to age and wrinkle. You want to be protected from both, of course, and most people turn to sunscreens for protection.
WTF is SPF?
Sunscreens are rated by a Skin Protection Factor (SPF) number. There is a great deal of misunderstanding about what the SPF number means. Most people assume that the higher the number, the better the protection. Not necessarily so.
The SPF number indicates the number of hours you can be exposed to the sun before getting burned. SPF 15 will protect you for 15 hours. SPF 50 will protect you for fifty hours. If you’re only going to be in the sun for a few hours, SPF 50 won’t necessarily protect you any better than SPF 15.
Another misunderstanding surrounding sunscreens has to do with the application. According to the SCF, “no sunscreen, regardless of strength, should be expected to stay effective longer than two hours without reapplication.” Second, “reddening” of the skin is a reaction to UVB rays alone and tells you little about what UVA damage you may be getting. Plenty of damage can be done without the red flag of sunburn being raised.
Should You Use Sunscreen?
The American Academy of Dermatology (AAD) recommends sunscreen for anyone that is going to be outside, whether it is rainy, cloudy, or sunny, and to apply more sunscreen every two hours. The AAD also say, “Use a broad-spectrum, water-resistant sunscreen that protects the skin against both UVA and UVB rays and that has an SPF of at least 30.”
The SCF recommendations are slightly different. “Anyone over the age of six months should use a sunscreen daily. Even those who work inside are exposed to ultraviolet radiation for brief periods throughout the day, especially if they work near windows, which generally filter out UVB but not UVA rays.”
Is it Safe?
The AAD says, “Yes, sunscreen is safe to use. No published studies show that sunscreen is toxic to humans or hazardous to human health. Scientific studies actually support using sunscreen. In addition, says the AAD, “Studies prove that using sunscreen reduces the risk of developing skin cancer. Other things you can do to reduce your risk are to seek shade and wear clothing that protects your skin from the sun.”