Mineral and chemical sunscreen filters are more similar than they are different, says Dr. Jennifer Beecker, an Ottawa-based dermatologist and the national chair of the Canadian Dermatology Association’s sun awareness program. “There’s been a lot of talk about potential concerns with organic or chemical filters that’s mostly been overblown in my opinion.” That said, Beecker often recommends mineral sunscreens to people with sensitive skin and for kids. “I think they’re a nice alternative for people who are looking for something that doesn’t have a chemical filter. They have a nice efficacy—they cover both UVA and UVB and often, they’re quite cosmetically elegant.” We asked her to answer our burning sunscreen questions.
Are mineral sunscreens better for sensitive skin? The physical structure of titanium dioxide and zinc oxide makes them inert by nature (translation: They’re not reactive and they play nice with other ingredients). “They tend to be a little bit more gentle on the skin,” says Beecker. That’s why you’ll often find zinc in eczema or diaper-rash balms.
Are mineral sunscreens less likely to clog pores? Not necessarily, but if you find that chemical sunscreens make you break out, a mineral formula might suit you better. A high-SPF chemical sunscreen may contain a large amount of different filters, which could be heavier on the skin and clog the pores.
Are minera l sunscreens with nanoparticles safe? Nanotechnology is used to create extremely small fragments of zinc oxide and titanium dioxide for use in sunscreens. Studies have shown there’s no danger of these nanoparticles absorbing into the skin in significant amounts. But Beecker points out that there is uncertainty about how nanoparticles affect the environment in the long-term.
Do mineral sunscreens need to be applied as often as chemical sunscreens? “It’s the same,” says Beecker. Mineral sunscreens are inherently photo-stable, meaning they won’t break down under sunlight and heat, whereas chemical filters are unstable on their own but can be stabilized by being combined with other ingredients. “Most people, if they put on [any] sunscreen properly, shouldn’t need to re- apply unless they’re sweating or swimming or towelling off.”
Do minera l sunscreens sta r t working as soon as you apply them? Technically, yes. However, the labels on both mineral and chemical sunscreens will caution you to wait at least 15 minutes after applying if you’re going in the water, a precautionary measure (and a legal requirement) to make sure it doesn’t wash off if you decide to take a dip.