ultraviolet radiation

7 Things to Know About Practicing Safe Sun

July 2, 2015

By Sheryl Smolkin

After a long winter, when summer weather finally comes, all I want to do is close my eyes and bask in its warming rays. It doesn’t seem possible that this is a high risk activity, yet melanoma skin cancer caused by damaging ultraviolet (UV) radiation is one of the fastest rising of all cancers in Canada.

But we all want retire healthy and live to a ripe old age. So the good news is that skin cancer is preventable if you practice “safe sun.” That means correctly applying sunscreen at recommended intervals and wearing protective clothing such as hats and sunglasses. Sunscreens are products combining several ingredients that help prevent the sun’s ultraviolet (UV) radiation from reaching the skin.

Two types of ultraviolet radiation, UVA and UVB, damage the skin, age it prematurely, and increase your risk of skin cancer. UVB is the chief culprit behind sunburn, while UVA rays, which penetrate the skin more deeply, are associated with wrinkling, leathering, sagging, and other light-induced effects of aging (photoaging). They also exacerbate the carcinogenic effects of UVB rays, and increasingly are being seen as a cause of skin cancer on their own. Sunscreens vary in their ability to protect against UVA and UVB.

SPF — or Sun Protection Factor — is a measure of a sunscreen’s ability to prevent UVB from damaging the skin. If it takes 20 minutes for your unprotected skin to start turning red, using an SPF 15 sunscreen theoretically prevents reddening 15 times longer — about five hours.

SPF 15 filters out approximately 93% of all incoming UVB rays. SPF 30 keeps out 97% and SPF 50 keeps out 98%. They may seem like negligible differences, but if you are light-sensitive, or have a history of skin cancer, those extra percentages will make a difference. And as you can see, no sunscreen can block all UV rays.

Here are 7 things you need to know about “practicing safe sun”:

  1. Who should use sunscreen? Everyone regardless of skin tone or ethnicity over age 6 months should use sunscreen. Younger infants should be kept in the shade or wear protective clothing.
  2. Cloudy days: Up to 40% of the sun’s ultraviolet radiation reaches the earth on a completely cloudy day. This often leads to the most serious sunburns, because people spend all day outdoors with no protection from the sun.
  3. Expiration dates: When it comes to sunscreen, expiration dates really do matter. The active ingredients in sunscreen can deteriorate over time, which means the protection won’t be as effective. What’s more, an open bottle is more likely to become contaminated with germs as the preservatives meant to prevent bacteria can also lose their efficacy. Read the suggested expiry date and storage conditions on the label.
  4. Choosing the right sunscreen: The kind of sunscreen you use may vary depending on the type of outdoor exposure you are expecting. For incidental sun exposure — when you are outside only for minutes at a time — an SPF of 15 is probably sufficient. Your sunscreen should have broad spectrum protection, meaning it effectively protects against significant portions of both the UVA and UVB ranges of the light spectrum. Most broad-spectrum formulas contain multiple sunscreen ingredients. For more detailed information on ingredients and how to choose your sunscreen, click here.
  5. SPF in your makeup: A two-in-one foundation/sunscreen certainly seems handy, but that doesn’t mean it works. Part of the problem is quantity: a dab of foundation isn’t the same as the amount of sunscreen you should slather on your face. However, a moisturizer with SPF can do the trick.
  6. How much is enough? To ensure that you get the full SPF of a sunscreen, you need to apply 1 oz. – about a shot glass full. At least four ounces per day with four applications means one 8 ounce bottle will only last the weekend. With 15 weekends between Victoria Day and Labor Day, you’ll need at least 15-8 ounce bottles per family member to get you through the season—even on rainy or cloudy days!
  7. Proper application: Sunscreens should be applied 30 minutes before sun exposure to allow the ingredients to fully bind to the skin. Reapplication of sunscreen is just as important as putting it on in the first place, so reapply the same amount every two hours. Sunscreens should also be reapplied immediately after swimming, toweling off, or sweating a great deal.

You can use both sunscreen and insect repellent to protect your health but be sure to read and follow the instructions on both containers to make sure that each product is applied properly. Health Canada recommends that if you apply both products; put the sunscreen on first, followed by the insect repellent.