How Does Sun Protection Work
Does it seem magical that you can smear a liquid or gel on your body and have it protect you from a painful sunburn? Well, there’s no magic, but there is a hefty dose of chemistry and/or physics involved.
How do they work?
Sunscreens, as a general category, rely on chemical compounds that absorb ultraviolet radiation (UV) and dissipate it in the form of heat energy. Your body actually has a faint red glow, which you can't see when you're out in bright sunlight!
Stacy and Ashley, NRS Marketing, on a lazy Lower Salmon day. Stacy has on her Tula Hat and just put away her Dermatone sunscreen. Hope Ashley remembered the sunscreen, or she's gonna burn! © George Caudle
What is ultraviolet radiation?
What is the SPF number you see on sunscreens?
As you can imagine, this is a laboratory test. On day one, an untanned person has a portion of their unprotected lower back exposed to artificial UVB rays. The length of time it takes for the skin to redden is recorded. The next day, a different area of the back is coated with the sunscreen being tested and the length of time until redness is recorded. The ratio of these two numbers is the product’s SPF rating. On the second day, the test subject probably gets paid for taking a nap.
Josh is pretty well protected: Kavu Hat, NRS HydroSilk Shirt and Boater's Gloves. The sun gets intense in the desert country along Oregon's Owyhee River. © Ashley Niles
Is an SPF 30 sunscreen twice as effective as an SPF 15?
So how do you protect yourself from UVA radiation? Select sunscreens that say they protect against both UVA and UVB, or bill themselves as “broad spectrum”. This is no guarantee, since there are no standards for UVA protection, but it can’t hurt. We’ll talk about other protective measures later.
How much sunscreen should you apply and how often?
Apply it 15-30 minutes before going into the sun, apply it liberally and thoroughly rub it in. Most recommend a reapplication about every 2 hours, especially if you are sweating, swimming or getting splashed while boating.
Can I still use the sunscreen I bought last summer?
NRS crew putting up a River Wing for protection from the blazing afternoon sun. ©Stacy Jensen
What is a sunburn and is there a healthy way to tan?
And remember, UVA radiation does not create visible sunburn. In the short term, its damage is invisible. In the long term, its deep penetration causes aging of the skin (the leathery, wrinkled, spotted look) and severe damage that can lead to skin cancer.
Okay, how can I fully protect myself from UV damage?
The sun’s rays are most intense from 10 am to 4 pm. Take special care to protect yourself during this time period.
Consider wearing sun protective apparel as much as possible when outdoors. The efficiency of this kind of clothing is rated as its Ultraviolet Protection Factor (UPF). A UPF of 45 means that only 1/45th of the UV rays that strike it will penetrate it. UPF 50+ is the highest rating given. You’re constantly protected in the areas covered by sun protective apparel; there’s no need to apply and reapply sunscreen. Wide brim hats really help shade your head, face and neck. These are some of the more exposed and sensitive areas of the body. Even if you don’t need gloves for palm protection while boating in the summer, wearing them gives the backs of your hands much needed protection.
As we said earlier, choose a broad spectrum sunscreen, or one that says it protects against both UVA and UVB radiation, with at least an SPF 15 rating. Apply it liberally and often, at least every 2 hours. Pay particular attention to the ears, shoulders, back and backs of the knees and legs.
Use extra protection around water, light sand and snow: they reflect the sun’s rays and intensify its effect. Kids can’t protect themselves; it’s your job to make sure they have on lots of sunscreen and protective clothing and play in the shade when possible.
Probably most of all, we need to lose the notion that a tan makes us look healthy, sexy and cool. Join the anti-tan generation – you’ll truly stay healthier and happier in the long run!
Boat Often & Boat Safe