More evidence that sunscreens absorb through skin

The US Food and Drug Administration has confirmed that six active ingredients widely found in sunscreens penetrate through the skin and absorb into blood plasma. The agency’s findings, published on Jan. 21, put pressure on manufacturers to determine whether such exposure to sunscreen ingredients is safe (JAMA 2020, DOI: 10.1001/jama.2019.20747).

“The fact that an ingredient is absorbed through the skin and into the body does not mean that the ingredient is unsafe,” Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research, says in a statement. “Rather, this finding calls for further industry testing to determine the safety and effect of systemic exposure of sunscreen ingredients, especially with chronic use.”

The FDA has yet to finalize a rule proposed in February 2019 that would require sunscreen manufacturers to provide safety data if their products contain certain ingredients, so that the agency can evaluate whether the chemicals are generally recognized as safe and effective. Those ingredients include the six chemicals—avobenzone, homosalate, octinoxate, octisalate, octocrylene, and oxybenzone—the FDA tested in its new study. The FDA wants the additional data because of increased use of sunscreens and potential risks.

The latest study follows up on earlier FDA work that found that four sunscreen active ingredients absorb through the skin (JAMA 2019, DOI: 10.1001/jama.2019.5586). Of the six compounds evaluated in the new study, three had been assessed previously and three were new. The FDA tested various formulations—lotion, aerosol spray, nonaerosol spray, and pump spray—on more people than the first study. After a single application, all six active ingredients in all tested formulations produced levels of the active ingredient in participants’ blood plasma greater than 0.5 ng/mL, the FDA’s threshold for potentially waiving safety studies.

The Personal Care Products Council and the Consumer Healthcare Products Association, which represent sunscreen manufacturers, noted in a statement that “there were no serious drug-related adverse events reported in the trial, consistent with the excellent safety record associated with sunscreen active ingredients over decades of real-world use.”

While the industry conducts further testing, the FDA is advising consumers to continue using sunscreens in conjunction with other measures, such as wearing protective clothing, to reduce the risk of skin cancer.