There's a health warning about a chemical found in most sunscreens. A 2017 study found that when that chemical comes into contact with sun and chlorine, it can become toxic.
If you flip over your sunscreen, chances are avobenzone is first ingredient you'll find. In fact, Boston's WFXT went into a couple of drug stores and found the vast majority of the sunscreens on the shelves have this chemical listed as the active ingredient. Avobenzone is the active ingredient in most sunscreens as it protects against UV rays.
“I have this one (because) I bought it just for my daughter, but I don't even know if it has it. Oh, avobenzone, there it is – first ingredient. And [the sunscreen is made] for babies, so that's not good,” said Candice Brown of Mattapan, Massachusetts.
“It's an incredibly common ingredient in sunscreen,” said Dr. Abigail Waldman, Brigham and Women’s dermatologist.
But a 2017 study first conducted in Moscow and published in the Chemosphere Journal, which is now being cited here in the United States, found that avobenzone can break down when exposed to a combination of light and chlorinated water, such as in a swimming pool, and it can degrade into some very harmful compounds, some of which are known to cause cancer.
“Anytime you put on a sunscreen or a lotion, it can react with chlorine and byproducts can form, which are chlorinated byproducts that can potentially could be harmful and whether that's on your skin initially or it's floating in the pool and you get exposed, those are two main ways of having exposure,” Waldman said.
Waldman explained that the particular concern is ingesting it, such as “after swimming in a pool and putting your hand in your mouth or sucking your thumb,” she said.
Waldman's advice is to keep kids' hands out of their mouths, towel or shower off immediately after pool time, and consider look for a sunscreen with zinc.
Mothers told WFXT that they're going to make the switch.
“So yeah, we gotta think about that,” Brown said.
Waldman also said that despite all of this, people shouldn't stop using sunscreen altogether.
She said using sunscreen, even with avobenzone, is better than using nothing at all because going without it can lead to skin cancer.
