ConsumerLab.com recently published an article on sunscreen safety. I’ve been thinking about this a lot after reading an article on zinc oxide losing its protective ability and actually becoming carcinogenic after it is left on the skin for a period of time. But I saw this in a Science daily article and hadn’t looked into the specific research. Note to self: Headlines are meant to get clicks!

The ConsumerLab.com article cleared up my confusion. Apparently, it is the combination of zinc oxide with organic compounds in chemical sunscreens that contain avobenzone, octisalate, homosalate, octocrylene, and oxybenzone. Not only are these compounds carcinogenic in general, they because zinc oxide to lose its UV-A protection and causes toxicity in a laboratory model.

I like to get a daily dose of vitamin D from the sun. Typically I try to get out for 20 to 30 minutes a day when weather permits. Admittedly, I’m one of those lucky people who doesn’t have a personal or family history of skin cancer so I have less concern about spending time in the sun. But vitamin D is also important to reducing the risk of all cancers including breast cancer and melanoma. So it’s important to balance your sun exposure in a way that gives you the benefit without the risk. The typical advice is to get the amount of daily sun exposure on bare skin that doesn’t lead to a burn.

Titanium dioxide only blocks UVB (which causes sunburn) while zinc oxide blocks both UVB and UVA (which causes wrinkles and sun spots). If you need to use sunscreen, look for one that contains zinc oxide or zinc oxide plus titanium dioxide. And reapply often. Avoid chemical sunscreens as they contain known carcinogens now on the FDA list to avoid. Many of these products have been recalled but others are still on the shelf.