4 things to know about the newly approved sunscreen ingredient : NPR

For the first time in nearly three decades, the Food and Drug Administration approved a new chemical UV filter for use in sunscreens sold in the US, and that has many dermatologists happy.

Says, “This is a big thing.” Dr. Heather Rogers, dermatologist in Seattle and fellow of the American Academy of Dermatology.

Rogers says the new ingredient is called bemotrizinol and has several advantages over chemical sunscreen ingredients already available in the US.

“It really ticked every box for us that we were waiting for as dermatologists and consumers,” says Rogers.

Here’s what you need to know about this new ingredient and how it could help sunscreens sell better in the States.

1. It blocks both UVA and UVB rays

Rogers says that in general, you want to use sunscreens that are broad-spectrum, meaning they protect against both UVA rays — long wavelengths that cause premature aging and wrinkles — and UVB rays, which cause sunburn. Both types of UV rays can cause skin cancer.

She says sunscreens currently sold in the US do an excellent job of protecting against UVB rays, but the chemical UV filters available in sunscreens in the US until now are not as good at blocking UVA rays.

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In general, chemical sunscreens sold in the U.S. rely on an ingredient called avobenzone to block UVA rays, says Kelly Dobos, a cosmetic chemist who teaches at the University of Cincinnati.

But avobenzone itself is not photo-stable, meaning its protection can begin to break down rapidly when exposed to sunlight. And as avobenzone breaks down, it can release molecules that irritate the skin, says Alexa Friedman, a senior scientist at the nonprofit Environmental Working Group, or EWG.

In contrast, bemotrizinol provides protection against both UVA and UVB rays on its own, and it is photostable, so it breaks down more slowly, providing better protection, Rogers says.

“So if you take a little more than two hours longer to reapply your sunscreen, there will be more protection left,” says Rogers. However, she says you should still reapply sunscreen every two hours.

2. It has been used in other countries for a long time

Bemotrizinol has been widely used in European and Asian sunscreens for decades. But it took 20 years for the FDA to approve its use in this country.

This is because in the US, sunscreens are regulated as over-the-counter drugs rather than cosmetics, as they are classified in Europe. This means that ingredients must undergo rigorous testing for safety and efficacy before they can be approved for use in the US.

“It’s really expensive and time-consuming,” says Dobos. The European company DSM-Firmenich spent at least $18 million over two decades to obtain FDA approval for bemotrizinol.

3. It has a well-documented safety profile

However, EWG’s Friedman says the testing means that bemotrizinol has more safety data to back it up than any other chemical sunscreen ingredient currently approved in the US.

“This component is exciting because we have data to support its safety,” says Friedman.

Friedman says animal testing has shown that bemotrizinol does not raise concerns such as reproductive harm, while clinical testing on humans has shown that it does not irritate the skin even after repeated application over time, “hopefully improving how people are using sunscreen.”

And because bemotrizinol’s molecules are large, it is not easily absorbed through the skin and into the bloodstream, she says.

This is important, because studies have shown that some other chemical sunscreens sold in the US may have UV filters absorbed into the bloodstream, leading to calls for more safety data and a backlash against sunscreens on social media due to misinformation. Rogers says this trend is worrying because skin cancer is the most common form of cancer.

“We just need sunscreens that people use, that they trust,” says Rogers. “And this component will allow that to happen. And that’s very exciting.”

And bemotrizinol is also considered non-irritating, says Friedman. This should be welcome news to those who have shied away from chemical sunscreens in the past.

4. It can make sunscreens that look better on you

Until now, Rogers says, the only sunscreen ingredient available in the US that provided the above advantages of bemotrizinol — photo stable, non-irritating, minimally absorbed into the skin and with good broad-spectrum protection against both UVA and UVB rays — was zinc oxide.

Zinc oxide and titanium dioxide are both mineral UV filters. Both chemical sunscreens and mineral sunscreens work by absorbing UV rays from the sun. Mineral sunscreens also reflect some UV rays. The big difference, says Rogers, is that mineral sunscreens stay on the skin’s surface, whereas chemical sunscreens are absorbed into the skin.

The downside of mineral sunscreens is that they can leave an unattractive white layer on the skin – think of a lifeguard with white paste on the nose. “Especially if you’re a dark-skinned person, zinc will make you look pale, white, or ashy, making it really hard to use on a regular basis,” says Rogers.

Bemotrizinol, on the other hand, is transparent on the skin, and because it protects against both UVA and UVB rays on its own, it doesn’t need to be mixed with many other chemical filters and stabilizers to get broad-spectrum protection, Dobos says. She says this should lead to more aesthetically pleasing, less greasy sunscreen formulations in the near future.

“I think this is a real win for public health,” Dobos says. “If we can create a sunscreen that consumers love to use and want to use and apply in appropriate amounts, I think that’s something that will really be a win for consumers.”

DSM-Firmenich has the exclusive right to market bemotrizinol in the US for 18 months. It will be sold under the brand name Parsol Shield. The company says the first sunscreen products containing this ingredient will begin hitting U.S. store shelves around September.