James' World 2

Click the link below the picture

.

The U.S. is finally getting a new, better sunscreen ingredient. Today, the Food and Drug Administration added bemotrizinol, an effective chemical filter that’s been used in sunscreens made in Asia and Europe for decades, to its list of permitted active ingredients in over-the-counter sunscreens. This list hasn’t seen a new entry in more than 20 years.

Bemotrizinol, also called BEMT, brings the list of approved active sunscreen ingredients in the U.S. to 17—a number that still lags behind Europe, which has more than 30 approved filters. While the FDA’s official action comes just seven months after the agency initially proposed it, critics have pointed out that the lengthy regulatory process prolonged bemotrizinol’s approval; the application was filed in 2005. The Environmental Working Group, an environmental health advocacy organization, has claimed this delay has caused U.S. sunscreens to fall behind in better coverage against harmful ultraviolet (UV) rays. Experts say today’s decision is a move in the right direction, offering people stronger protection from the sun.

Expanding sunscreen ingredient options in the U.S. is “a pretty big deal,” says AJ Addae, a chemist and doctoral candidate a University of California, Los Angeles, who studies cosmetics and sunscreen formulations. “It’s definitely something that we haven’t had in a very long time.”

How Bemotrizinol Works

There are two main classes of sunscreen filters: inorganic, or “physical,” and organic, or “chemical.” Sunscreens with physical filters—such as titanium and zinc—are mineral-based and are known to leave a white cast on skin. Chemical filters, such as avobenzone, octocrylene, and homosalate, appear clear when rubbed on the skin but sometimes feel oily. There are more organic filters than inorganic ones, but there aren’t as many approved ones in the U.S. as in other parts of the world, Addae says.

Contrary to popular belief, both types primarily work by absorbing UV light and converting that radiation energy into heat that is released from the skin, explains Saranya Wyles, a dermatologist at the Mayo Clinic in Minnesota. All sunscreens have the ability to reflect some light, though inorganic filters can reflect a little more, Addae adds.

UV radiation comes in two types: UVA and UVB. UVB is high-energy radiation that is typically associated with sunburns and can cause genetic mutations that lead to skin cancer, but UVA rays have increasingly become recognized as relevant for skin health, too. UVA is a longer-wavelength radiation that can penetrate deeper into the skin than UVB, breaking down the skin’s structure and creating harmful, skin‑aging molecules.

In the U.S., “the only thing that is really tested is a sunscreen’s ability to absorb UV light—specifically UVB light,” Addae says. This is how sun protection factor (SPF) is determined, but the measurement doesn’t capture UVA light. U.S. sunscreens offer only 24 percent of the protection indicated on SPF labels against UVA radiation, according to an analysis by the Environmental Working Group.

“When we think about a sunscreen, we want something to be broad spectrum,” Wyles says—meaning it covers both UVA and UVB. “What’s so exciting about this new BEMT filter is that it has more coverage in that UVA spectrum” compared with other organic filters. BEMT covers those “deeper UVA” rays that are often linked to photoaging of the skin, she says.

Safety and Stability Properties

Between various countries’ regulatory approval and real-world use, bemotrizinol has some of the most robust safety and efficacy testing among sunscreen filters. Following the ingredient’s development in the late 1990s by the now defunct Switzerland-based company Ciba Specialty Chemicals, the European Union adopted it into sunscreens in 2000. Canada and several countries in Asia followed suit soon after.

“A ton of safety data have had to be accrued in a lot of different populations,” Wyles says. Companies developing sunscreen filters need lots of funding to get the data needed for approval in the U.S., she adds.

Not only is bemotrizinol now the first filter to obtain the FDA’s stamp of approval since 1999, it’s also the first and only organic filter to receive the FDA’s safety and effectiveness standard, known as generally recognized as safe and effective (GRASE), for over-the-counter drugs or ingredients that don’t require full regulatory approval. The GRASE designation “is huge,” Addae says.

“I think that will kind of debunk the consumer’s perception that inorganic filters are generally recognized as safe and effective and organic filters tend to not be,” she says. “This shows that there can be organic filters that are that are determined GRASE.”

It’s impossible to draw “a clear line in the sand” on whether certain sunscreen ingredients are completely healthy for people or not, Addae says. But she adds that evidence has emerged that has given researchers some insight into how sunscreen filters generally interact with our bodies. Chemically, BEMT has larger chromophores—light-absorbing molecules—than other organic filters, which makes them less of a concern for adverse biological interactions, Addae says. In pharmacology and dermatology, researchers use the “500 dalton rule,” in which molecules with a molecular weight of more than 500 daltons are usually too large and bulky to pass through the skin.

“BEMT exceeds this limit quite well,” Addae says. “I think that’s likely a large reason why the GRASE status was on the table for this particular filter.”

Scientists are investigating whether BEMT degrades in pool water. It’s unclear if subsequent chemical by-products after a breakdown of BEMT might cause irritation or damage to the skin. In sunlight, though, most evidence suggests that BEMT is quite stable and longer-lasting than other filters. “BEMT is one that does stay on longer, but this doesn’t mean you can apply this and then you don’t have to reapply for a long time,” Wyles says. “That degradation curve varies for everybody.”

The FDA evaluated the safety and efficacy of BEMT concentrations of up to 6 percent and considered how BEMT interacts with other sunscreen filters and ingredients. Because companies will only be able to use up to 6 percent concentrations of BEMT in formulations, Wyles doesn’t anticipate it will fully replace existing U.S. filters.

“A lot of times, you’re not going to see BEMT standing alone; it’s going to be combined with other sunscreen filters,” Wyles says.

The Future of UV Filters

Researchers are keeping tabs on how BEMT’s approval will affect the approval of other UV filters in the U.S. Wyles says others in the BEMT family might see similar approvals. Another organic filter, Mexoryl 400, has also demonstrated coverage of the UVA spectrum and is increasingly found in sunscreens produced in Asia and Europe. “I can see that coming to the U.S. at some point,” Wyles says.

Addae, who also created a research-and-development lab to make products for cosmetic chains, recently worked with her colleagues at U.C.L.A. to create a mineral-based filter with less of a white cast. She changed the chemical properties of zinc oxide to reduce aggregation that causes a white cast. The filter scattered light differently but still absorbed UV rays effectively. It was more effective with UVB than UVA rays, however. Further efficacy testing is needed, but the filter wouldn’t require new regulatory approval, she says.

BEMT sunscreens are anticipated to hit U.S. shelves later this year. The Dutch company DSM Nutritional Products will be the first in the U.S. to sell its BEMT-formulated sunscreen, Parsol Shield, according to the Associated Press. The company has an 18-month exclusivity period, after which the other manufacturers can start using the ingredient. Addae adds that it will take some time for U.S. chemists and companies to incorporate the filter into new products and learn best practices.

“At the end of the day, what matters is that people wear their sunscreen, no matter what’s in it,” she says.

.

Pablo Jeffs Munizaga/Fototrekking/Getty Images

.

.

Click the link below for the complete article:

.

__________________________________________