What Exactly Is SPF?
SPF stands for sun protection factor. Simply put, an SPF rating tells you how long you can stay in the sun without getting burned while wearing sunscreen, compared with how long you can stay in the sun before you burn without wearing sunscreen.
What Are UVA, UVB, and UVC Rays?
The sun is a giant ball of energy, and that energy provides us with light and heat. These waves of light are where ultraviolet rays come from. The majority of the sun’s light rays we can see because they are longer wavelengths, but UVA, UVB, and UVC rays are invisible to the human eye because their wavelengths are shorter.
UVC rays are not known to be a concern because they are so short that they don’t reach the earth, therefore we’re never directly exposed to them.
UVB rays are the next longest, and they’re the rays that only penetrate the top layer of our skin and cause us to burn. They’re stronger during the summer months, but they are around year-round.
Have you ever been burned during the winter when there was snow all over the ground? UVB rays can reflect off of water and snow, and these are the rays that are most likely to cause skin cancers.
UVA rays are the longest of these three, and they penetrate the top two layers of our skin and are known for their aging effects.
Tanning beds use UVA rays to tan the skin so not only do you get a bronze look; over time you also get lots of wrinkles to go along with it.
Another thing to consider is that most people don’t use enough sunscreen anyway or reapply it often enough. The general rule of thumb is to apply 1 ounce of sunscreen (about a shot glass full) each time you apply it in order to get the full SPF protection the sunscreen is supposed to provide.
What You Wear Matters
Generally speaking, long sleeves and pants are more protective than tank tops and shorts. But even if you’re covered in clothing from head to toe, there is a chance that sun can make its way right through fabric fibers.
When some fabrics are examined under a microscope, especially if they are made from fibers knit or woven together, space between fibers is visible.
UV rays can penetrate through those spaces and reach skin. The more tightly knit a fabric is, such as denim, the less likely UV rays can get through. The less tightly knit a fabric is, such as linen, the more likely UV rays can get through.
If you opt for lightweight, summery fabrics, you should still apply sunscreens even on parts of the body that are covered up.
Wearing sun-safe clothing is a great additional measure you can take beyond wearing sunscreen to help protect your skin from the sun. It’s especially a great idea for young, active children who may have trouble sitting still for a few minutes while a parent tries to apply sunscreen, and who are often in and out of a pool or ocean.
UPF clothing is made with fabric that protects skin from the sun. UPF stands for ultraviolet protection factor, a rating that indicates what fraction of the sun’s UV rays can penetrate fabric.
For example, if you are wearing a shirt with a UPF rating of 50, that shirt allows for 1/50th of the sun’s UV radiation to reach skin underneath the shirt.
UPF clothing is becoming increasingly more common, especially in kids’ clothing and beachwear items like rash guards.
While a quality sunscreen and appropriate clothing can protect you from the sun, you should also avoid working outside during peak daylight hours. Seek shade between 10 a.m. and 4 p.m. when the sun is at its peak.
You are more likely to get skin damage during these hours, especially with sensitive skin. Even in the winter, sun protection is still important.
You should also protect yourself indoors and while driving because the sun can penetrate through windows. In your car, transparent window film screens can block out the sun rays; at home, draw blinds closed during peak sunlight hours.