Advice | Make sure your sunscreen is at least 30 SPF, but the rest is up to you

When it comes to choosing a sunscreen, there’s plenty to think about.

Is the sun protection factor (SPF) high enough? Should we pick spray or lotion? What’s the difference between “chemical” and “mineral” sunblock? Add to these questions two less obvious ones: Is our sunscreen inclusive and is it accessible?

We decided to ask some experts, starting with the great sunscreen divide: “chemical” versus “mineral.” Since few people like the idea of applying chemicals to their skin, the answer might seem obvious. It’s more complicated than it appears, though.

“The thing is that minerals are chemicals, too,” said Dr. Cheryl Rosen, head of the division of dermatology at Toronto Western Hospital and University Health Network Hospitals, and a professor of medicine at the University of Toronto. “So the sunscreens that are called ‘chemical’ (most of them have been around for a very long time) have organic chemicals, and Health Canada has rules about what percentage of each of those can be used safely in a sunscreen.”

When it comes to sunblock, the term “chemical” is a reference to the way this type of protection works: active ingredients are absorbed into the skin, where a chemical reaction converts UV rays into heat, which is then released. “Mineral” sunscreens, on the other hand, contain physical material that sits on the skin and literally reflects the sun’s rays off the skin. Sometimes they are referred to as “physical” sunscreen instead of “mineral.”

“Some people prefer mineral sunscreens because there have been studies that have shown there is some absorption of some of the chemical sunscreens,” Rosen explained. “But there’s never been a signal that has shown that absorption leads to any biological harm.”

The chemicals may not have been shown to be harmful, but they can be an irritant, particularly to people with other health problems and/or skin conditions, said Dr. Hermenio Lima, a clinical immunologist and dermatologist, leader research director and professor at McMaster University’s medical school.

“Depending on the patient’s specific skin problem, there may be a big difference between the two,” Lima said. “If you have eczema, for instance, your skin might not be able to cope with chemical sunscreen.”

Lima also counsels patients with photosensitivity issues to use mineral sunblock, since it has a very “broad spectrum,” meaning that it not only reflects UVA and UVB (ultraviolet light, which tends to be what people worry most about) but also protects people from other forms of light, such as infrared, which can be dangerous for people with certain conditions such as lupus.

One problem with mineral sunblock, however, is that, with the exception of a few tinted products, the vast majority of them aren’t person of colour-friendly.

“Something that I struggle with is finding a sunscreen that doesn’t leave a ‘white cast,’” said Kristina Knox, co-founder of Arbre, a Toronto company that is working on inclusive sunscreens. “Especially with mineral ones, which just don’t blend in with darker skin tones very well. Then you’re left looking washed out or purply, so one of our goals with our company is to really create sunscreens that work for everybody.”

Arbre’s first product is a mineral-based powder sunscreen that won’t cause white cast. It’s still being evaluated by Health Canada, but the hope is that it will be ready to sprinkle by the end of the year, just in time for winter vacation season.

Why powder? Because the Arbre project began when the other co-founder, Stephanie Tien, who met Knox while studying science at U of T, took a trip to Wasaga two summers ago and came home with a bad sunburn on her scalp, where her hair parts. Nobody wants to put lotions near their hairline or in their part, so powder is a good solution.

And it’s not just hairlines we miss when we apply sunblock. People often forget their ears, miss the middle of their back or completely overlook the tops of their feet.

“I have a picture of a woman who was asked to put on sunscreen with fluorescent dye in it,” said Rosen. “They use a light to show where the sunscreen is and you can see these whole areas that are missed.”

Proper application may be a bigger problem than SPF, in fact. Few people reapply it every two hours, for example, especially since, if they did, a long day at the beach might require an entire tube — an expensive prospect over an active summer.

And, as Lima explained, this points to another other issue: accessibility. We treat sunscreen as a cosmetic but, in fact, it’s a preventative health tool that could save lives and, of course, money for the health-care system, since treatment is always more expensive than prevention.

“In order to reduce skin cancer rates, we have to make sure the population has access to sunblock,” said Lima. “It should be prescription-based, included in health insurance and provided for patients who get any sort of government support.”

Unlike medication, dental care and eyeglasses, sunblock isn’t terribly high on the list of things people think our health-care system should be expanded to include. Lima said one reason for this might be that we don’t have a great system to track data on skin cancers, particularly non-melanoma skin cancers (basal cell carcinoma and squamous cell carcinoma). Many Canadians don’t realize how prevalent they are.

To help address the knowledge gap when it comes to skin cancer, Lima and colleagues are working on a project that will see robots help patients learn about the importance of proper protection.

As to the SPF, well, that one is easy. Health Canada recommends 30 SPF, but many experts say you can go as high as 50. And what’s better: lotion, spray or powder? Also easy: pick the one you like.

“You don’t have to make it that complicated,” said Tien, “You know, if it’s messy or doesn’t blend with your skin, you’re not going to use it, so it’s just choosing the one that works for you and that you’ll actually want to use. That’s the most important thing.”

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