Single use of sunscreen can see six different chemicals leach into the bloodstream, reveals FDA study
Six chemicals found in sunscreen are capable of seeping through the skin and reaching the bloodstream, after just one use. Once these ingredients make their way into the body, they stay for extended periods of time -- at levels exceeding US Food and Drug Administration or FDA's threshold.
These findings from a study conducted by the FDA add weight to a previous study carried out by the same researchers. It claimed that four sunscreen chemicals entered the bloodstream, when users followed instructions printed on product labels.
However, the FDA does not know whether these chemicals are dangerous. "The findings in these studies do not mean that the FDA has concluded that any of the ingredients tested are unsafe for use in sunscreens," according to Dr. Theresa M Michele, Director and Dr. David Strauss, from the Center for Drug Evaluation and Research, in a press statement.
"Just because it is in the blood does not mean that is not safe. It does not mean it is safe either. The answer is we do not know," Dr. Adam Friedman, chairman of dermatology at George Washington University, tells Reuters. Further testing will shed light on whether exposure to sunscreen ingredients spell trouble, adds the FDA.
Sunscreens are handy, they block the harmful UV radiation, helping users keep skin cancer at bay. “Any conversation on sunscreen must start with acknowledging that there is robust evidence that it prevents skin cancer,” Richard Weller, honorary consultant dermatologist at the University of Edinburgh, tells the BBC.
But sunscreens may not be completely safe, as some research suggests. In theory, some chemicals could pose dangers to human health, including a role in infertility or cancer risk. Previously, the FDA pulled out 14 of the 16 chemicals found in sunscreens from its GRASE (generally accepted as safe and effective) category.
To deepen our understanding of these chemicals, the team carried out the second study. "In addition to studying application every two hours according to the product label, we also studied absorption after a single use," reads the statement.
The research team tested sunscreens -- lotion, aerosol and non-aerosol spray, and a pump spray -- on 48 healthy volunteers. Participants applied sunscreen that contained six chemicals: avobenzone, oxybenzone, octocrylene, homosalate, octisalate, and octinoxate. This continued for four days. Next, they tested the levels of these chemicals in the blood for 21 days, starting with the first day of sunscreen use.
Though participants discontinued using the sunscreen after the fourth day, scientists could still detect all the six chemicals in the blood: their levels continued to rise until the 21st day. The chemical levels peaked on the seventh day, reaching levels beyond FDA's recommended levels, says the study.
"It seems likely that some of it is absorbed into the blood long after the sunscreen applications and in part that is why levels in the blood stay high weeks after application," David Andrews, a senior scientist for the Environmental Working Group, or EWG, a consumer organization which advocates for sunscreen safety, tells CNN.
"The skin is not a perfect barrier and so absorption of small amounts of chemicals from sunscreen is to be expected," says Rob Chilcott, a professor of toxicology at the University of Hertfordshire in the UK. "This does not mean that sunscreen products are unsafe to use, but that appropriate safety tests need to be performed by manufacturers," he adds.
The study has been published in JAMA.