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SPF Test Debate Sizzles
By: Nancy Jeffries
Posted: October 10, 2008, from the February 2006 issue of GCI Magazine.
page 3 of 6
Joseph Stanfield, president of Sunscreen Research Laboratories, LLC, cited SPF testing approaches worldwide. “The International Method (Cosmetic, Toiletries and Fragrance Association of South Africa; The European Cosmetic, Toiletry and Perfumery Association; Japan Cosmetics Industry Association and the International Sun Protection Factor Test Method and Final Draft October 17, 2002), is by far the most comprehensive and scientifically rigorous method for SPF testing,” said Stanfield. “It includes detailed specifications for solar simulators, detailed instructions for product application and an instrumental method for determining skin types of human volunteers. We can only hope the FDA will adopt the International Method so that rational international harmonization may be achieved.
“Unfortunately, there is no finalized international method for water-resistance testing, and the proposed method is too cumbersome, and actually too lenient, in my opinion,” added Stanfield. “A product can be labeled as ‘very water resistant’ if the SPF, after 80 minutes of water immersion, is above 50% of the static SPF value. Further, the proposed international in vitro method for substantiating UVA protection claims is too complicated and makes incorrect technical assumptions for dealing with products that are unstable or marginally stable in sunlight.”
Achieving agreement is difficult among manufacturers, dermatologists and regulatory agencies. “I am not optimistic that simple, rational methods for substantiating water resistance and supporting UVA protection claims will be achieved in the foreseeable future. This means that confusion among consumers, and even dermatologists, will persist,” added Stanfield.
Key activities of sunscreen formulations include preventing sunburn, reducing UVA dose, providing water resistance and achieving photostability. “This sounds simple, yet there’s no agreement on the recommended SPF level for consumers of varying skin type and outdoor activity, no agreement on the level of UVA protection needed, no test that actually predicts water resistance in actual use and no standard for photostability,” said Stanfield. “I believe SPF numbers are essentially meaningless and water resistance claims misleading. The need for UVA protection has not been studied adequately, and the most often used UVA absorber, avobenzone, is notoriously unstable in sunlight. In fact, I believe it is safe to say that no sunscreen product that contains only avobenzone and octinoxate is photostable.”
Stanfield said sunscreens do work well, and manufacturers would be receiving more complaints and dermatologists would be treating more patients with severe sunburns and skin reactions if they didn’t. Having been involved in SPF testing for 25 years—almost since the U.S. Food and Drug Administration (FDA) published the first proposed Sunscreen Monograph—Stanfield believes it’s time for the industry to address the FDA with clear, scientifically valid information that simplifies testing and protection claims.