When Karin Mossman heads outdoors with her young family, she mentally runs through her list of must-haves. Jackets? Got ’em. Hats? Check.

Sunscreen? Probably not.

“I’ve made a decision to avoid using sunscreens as much as possible to almost not at all,” says the Calgary mom.

She used to rub sunscreen on her kids whenever they played in the sun. But over the past few years, she’s adopted a more measured approach — using sunscreen rarely, only when “absolutely necessary.” A day of swimming, for instance, might warrant sunscreen.

She relies on shade, hats and clothing to protect her family from the sun’s rays. When she does use sunscreen, she chooses products that are as natural as possible.

“Generally speaking, I’ve decided to err on the side of caution with respect to sunscreens,” she says.

Mossman says she worries about potentially toxic ingredients in sunscreen lotions. Many of the chemical blockers used in sunscreen to shut out ultraviolet rays have not been studied for long-term effects on human beings to her satisfaction, she says. And not all the ingredients are listed on the packaging — an omission that bothers Mossman.

Her understanding of the science suggests that risks of sunscreen are “not worth it from a toxicity point of view,” she says.

For parents, slathering sunscreen on their kids isn’t as simple as the “more is better” message that was de rigueur just a decade ago.

Although many instinctively reach for the sunscreen, some say they are concerned about the safety of sun lotions and gels. There’s been a spate of conflicting reports over the past several years: some claim that sunscreen ingredients might elevate cancer risk, others suggest that sunscreens inhibit Vitamin D production.