FDA: Why Bigger Isn't Better When it Comes to SPFs


June 17, 2011

WHYY/NPR

WHYY Radio reports on Food and Drug Administration's new sunscreen regulations which will require lotions to protect against both UVA and UVB rays, and will not allow them to be marketed as waterproof, only water-resistant. A proposed rule up for public comment would also ban labeling sunscreen with SPFs higher than 50. Joseph Sobanko, MD, a dermatologic surgeon at the Hospital at the University of Pennsylvania, said lotions with SPFs of 80 or 90 are just not more effective. Think of the sun protection curve as an asymptote, he said. "When you're applying an SPF of 15, you're blocking out about 92 and a half percent of radiation from the sun,” Sobanko said. “When you approach an SPF of 20, you're blocking about 95 percent of UV rays." At SPF 40, that only bumps up to 97.5 percent. "A double in the SPF does not translate into a double of the amount of ultraviolet rays that you're blocking out,” Sobanko said... Read More