Up to 50% of SPF labels inaccurate, but that may soon change

MAUI, HAWAII — Products that utilize SPF labels have an uneven track record for accuracy, a speaker at Maui Derm for Dermatologists 2020 told attendees.

“Consumer Reports found that as many as 50% of the sunscreens do not meet their label claims,” Curtis Cole, PhD, president, Sun & Skin Consulting, said. He serves on an International Organization for Standardization (ISO) committee that is revising the global SPF testing method known as ISO 24444.

“We are taking a number of steps to get much more uniformity on labels,” Cole explained. “We are asking people questions about reactions to the sun in the springtime. We are asking people [who use certain products]: do they always burn, do they never burn, do they sometimes burn, do they sometimes tan, and so on.”

The ISO also added several criteria to its SPF accuracy protocol testing as part of the ISO 24444 revision process. According to Cole, some of these criteria include setting SPF-25 and SPF-60 reference standards, mandating a range of unprotected minimal erythema doses instead of allowing them to be too high or too low, adding photos to help codify what a qualifying minimal erythema dose is, and removing subjective elements out of the SPF custom methodology.

Until SPF labels can become more accurate, Cole offered a few tips that clinicians can share with patients about maximizing sunscreen use:

• Apply two doses when first exposed to sunlight to ensure no exposed body parts are missed. This second dose should be applied as soon as the first one dries.
• Avoid calculating times that they would be safe in the sun or how quickly they are to burn, since these are often inaccurate.
• Choose a product whose features are aesthetically pleasing so that it will be applied liberally.

Cole noted that the FDA is not obligated to follow the ISO’s lead. However, he expressed hope that the U.S.-based agency would someday follow the international organization’s example. – by Janel Miller

Reference: Cole C. Hot topic: Controversies in photoprotection. Presented at: Maui Derm for Dermatologists; Jan. 25-29, 2020; Maui, Hawaii.

Disclosures: Cole reports serving as a paid consultant to Solar Light Company; several sunscreen manufacturers and numerous SPF testing laboratories; and serving as an unpaid consultant to the Sun Protection Foundation.