80% of Sunscreens Ineffective, New Study Says

CBS 5 KPIX, Dr. Kim Mulvihill, M.D.
Published July 10, 2008

Sunscreen—it's a billion dollar a year business. "I use sunscreen on a regular basis," says one sun worshipper. Slather it on to protect your skin. But is it safe and effective? A new study from the Environmental Working Group says that for 4 out of 5 sunscreens, the answer is "no." One reason? The difference between UVA and UVB rays. Traditionally, sunscreens have done a good job protecting against UVB rays that cause sunburns, but not against UVA rays, the ones that penetrate more deeply into your skin and lead to premature aging—and wrinkles. Both types of UV light can damage your skin, damage your DNA, and lead to skin cancer. "We know now clearly it's the UVA rays that are actually the most dangerous," said Dr. Mark Steven Nestor, a dermatologist. The best protection against UVA rays is a sunscreen that contains zinc oxide, titanium dioxide, or avobenzone. But avobenzone, a popular ingredient, weakens when exposed to sunlight. A new technology used in processing, called "Helioplex," may help. Helioplex stops avobenzone from breaking down. "It allows for this UVA agent to be much more stable and act much longer. Up to about 5 hours," said Dr. Nestor. The other concern is that sunscreen gives wearers a false sense of security, and they'll stay in the sun longer.