More traditional products rely on octisalate (found in 59 percent of products, according to the EWG), oxybenzone (found in 52 percent) and avobenzone (found in 49 percent). Oxybenzone presents the most concerns; it can trigger allergic reactions, is a potential hormone disrupter, and penetrates the skin in relatively large amounts, according to the EWG.
"There has been a lot of hype about possibly causing endometriosis or increasing skin cancer," Brewer said. "The bottom line is, sunscreen continues to be one of the most effective methods of sun protection available."
Oxybenzone has been approved by the FDA since 1978.
"Available peer-reviewed scientific literature and regulatory assessments from national and international bodies do not support a link between oxybenzone in sunscreen and hormonal alterations, or other significant health issues in humans," said Dr. Daniel M. Siegel, president of the AAD, in a 2012 statement.
"The FDA has approved oxybenzone in sunscreen for use on children older than six months, and dermatologists continue to encourage protecting children by playing in the shade, wearing protective clothing and applying broad-spectrum sunscreen."