Sunscreen Facts You Need to Know

By Stephanie Tweito Jacob for Life & Beauty Weekly

You know sunscreen is a must whenever you’re outside — so why does sunburn still sometimes catch you by surprise? By slathering on sunscreen, you may have thought you were playing it safe, but there’s actually more to it than that.

“Unfortunately, there is a lot of misinformation about sunscreen,” says Dr. Barry A. S. Lycka, founder and past president of the Canadian Skin Cancer Foundation. “For instance, most people realize milk has an expiry date — but creams they put on the skin, that’s different. Here’s a million-dollar lesson: Sunscreens expire too. Their ingredients break down over time.”

Check out these other common sunscreen myths, plus the facts that will keep your fun in the sun safe.  

Myth: You’re protected as long as you apply sunscreen as soon as you get to the beach or park.

Fact: You must apply it about 30 minutes before you head outside.

“When you put a sunscreen on, it takes a while for it to ‘soak in,’” Lycka says. “It needs to get into the top layer of the skin, the stratum corneum, to be effective.” Since your skin starts taking in rays from the minute you walk outside, by the time you get to your destination, you may have already sustained some UV damage. Apply well before you head out to stay safe.

Myth: Hair provides your scalp all the sun protection it needs.

Fact: You can get burned through your hair.

Exposed areas on your scalp (for instance, your part and around the hairline, where hair tends to be thinnest) are hotspots for sunburn. And your head is just as vulnerable to sun damage and skin cancer as the rest of your body, Lycka says.

Your best defence is a hat, which provides a physical barrier from the sun’s rays. You can also apply a spray or gel sunscreen (these aren’t as greasy as lotions) to your part and hairline area. “All sunscreens work to prevent burns if enough is put on and wind, sweat, rubbing, etcetera don’t take it off,” Lycka says. “Unfortunately all these things do take it off,” so be sure to reapply regularly.

Whatever you do, don’t rely on UV-shielding hairsprays or styling creams. These are meant to protect your hair colour from fading in the sun, but they won’t protect your skin.

Myth: A high SPF will protect you all day.

Fact: There’s no such thing as all-day protection.

Whether it’s SPF 15 or 50, all sunscreens stop working after about two hours. A sun safety rule: Use a minimum of SPF 30 and reapply after two hours outdoors. And be sure you’re applying enough of it. “Aim to put on at least 60 ml in each application,” advises Lycka.

Myth: You don’t need to reapply waterproof or water-resistant sunscreen after a swim.

Fact: Those terms only mean you’re protected in the water.

Don’t confuse “water-resistant” and “waterproof” with towel-proof. “No sunscreen sticks to the skin like glue,” says Lycka. “Water washes it off. It needs to be reapplied after swimming.” Even though waterproof sunscreens have strong staying power, none of them is 100 percent waterproof. Lotions only protect skin for about 40 minutes in the water.

Myth: You can skip sunscreen if you’re tanned or have dark skin.

Fact: All skin tones need protection.

The truth is, sun damage doesn’t discriminate. And a burn isn’t the only sign of unhealthy sunning: “Dark skin and a tan has an SPF of only two,” Lycka says. “Wrinkling and burning” will still happen.

Myth: Young babies shouldn’t use sunscreen.

Fact: Children over the age of six months can wear sun protection.

“A baby younger than six months should not wear sunscreen,” Lycka says. “The sunscreen is absorbed through their permeable skin and can be harmful. Therefore, sun should be avoided in this age group.” If you do go outside with a young infant, use physical blockers — UV-protective cotton pants, long-sleeve shirts and hats — to protect his skin.

After a baby has turned six months old, Lycka recommends using an SPF formula made specifically for infants. These usually contain mineral-based blockers (like titanium dioxide or zinc oxide), which tend to be gentler and non-irritating.

Stephanie Tweito Jacob is a freelance writer who specializes in beauty, fashion and health. She has held editorial positions at Allure, More and O, The Oprah Magazine.