European sunscreens

Key Points

National report - The apparent superiority of many European sunscreens has less to do with the availability of ingredients in the United States than with manufacturers' formulation decisions, an expert says.

Furthermore, he adds, the absence of SPF ratings on 10 percent of European Union (EU) products partly offsets the European products' advantages.

In the latter area, researchers applied 0.75 mg/cm² of the sunscreen product uniformly to the roughened side of a polymethylmethacrylate (PMMA) plate with a pre-saturated finger cot. They then allowed the film to dry under ambient conditions for 15 minutes.

Soaking up the rays

Researchers then measured products' UV absorbancy using a Labsphere UV-1000S Ultraviolet Transmittance Analyzer (Labsphere).

After establishing reference absorbancy measurements on a glycerin-treated PMMA plate, they measured UV absorbancy of the product films at six different sites on each substrate. For each sunscreen product, researchers used three independent replica plates. Finally, researchers corrected product sample measurements using the glycerin-treated reference to establish absorbancy curves that they used to calculate product efficacy.

This analysis showed that more than 80 percent of EU products surveyed provide broad-spectrum UVB and UVA protection (based on American Academy of Dermatology criteria: critical wavelength of at least 370 nm and persistent pigment darkening/PPD of 4 or greater; or European Commonwealth recommendations - ratio of in vitro PPD: label SPF greater than 0.33). These findings are consistent with higher use of UVA actives, Dr. Nash tells Dermatology Times.

However, he notes that the European sample contained "a higher percentage of products that provide less than SPF 15 and a higher percentage that lack SPF labeling entirely," usually facial moisturizers.

SPF claims

Regarding SPF claims, 21 percent of the European products studied offered SPF 4 to 14, versus 10 percent of the U.S. market, Dr. Nash says.

Conversely, about 50 percent of EU products fell into the SPF 15 to 29 range, versus a little more than 30 percent of domestic sunscreens. Findings were roughly equal in the SPF 30 to 50-plus range - 40 percent of European products versus about 38 percent of U.S. products.

"Within the products sold in Europe," Dr. Nash says, "a higher percentage have long wavelength or UVA protection. And they're more balanced, providing a breadth of protection against solar UV from 290 to 400 nm." In that sense, he says European products are "ahead of products sold in the United States. But the surprising aspect was that the majority of those (European) products contain the same UVA filters that are approved in the States - avobenzone, titanium dioxide and zinc oxide."

He says 80 percent of European products tested contained at least one of these ingredients.

"From the perspective of a U.S. manufacturer," Dr. Nash notes, "we should be moving toward incorporating these filters in more of the products we make available" to provide the same breadth of protection.