Sunscreen enters bloodstream after just one day of use, study says

Sunscreen could cause vitamin D deficiency
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The US Food and Drug Administration is proposing new regulations on over-the-counter sunscreens in an effort to keep up with the latest scientific and safety information.

It took just one day of use for several common sunscreen ingredients to enter the bloodstream at levels high enough to trigger a government safety investigation, according to a pilot study conducted by the Center for Drug Evaluation and Research, an arm of the US Food and Drug Administration.

The 10-year study found that 70% of people had a positive patch test when exposed.

A 2018 report by the EWG estimated that it was in two-thirds of all chemically based sunscreens sold in the United States.

Protect yourself from the sun

In an editorial accompanying the new study, former FDA Chairman Dr. Robert Califf assured readers that just because the research found chemical levels “well above the FDA guideline does not mean these ingredients are unsafe.”

The Personal Care Products Council, the national trade council for sunscreen, cosmetic and personal care products, agreed in a statement.

“The presence of sunscreens in plasma after maximal use does not necessarily lead to safety issues,” said Alex Kowcz, chief scientist for the council.

“It’s important for consumers to know that for the purpose of this study, sunscreens were applied to 75% of the body, four times per day for four days — which is twice the amount that would be applied in what the scientific community considers real-world conditions,” Kowcz said. The council was concerned, she said, that the FDA’s study might confuse consumers and discourage the use of sunscreen.

When going outside, the American Academy of Dermatology recommends applying at least 1 ounce of sunscreen to all exposed skin every two hours or after swimming, including “back, neck, face, ears, tops of your feet and legs. If you have thinning hair, either apply sunscreen to your scalp or wear a wide-brimmed hat. To protect your lips, apply a lip balm with a SPF of at least 15,” the academy says, adding that since UV rays are always present, sunscreen should be applied to exposed skin even on cloudy days and in the winter.

Research urgently needed

Califf said next steps would be appropriately designed clinical trials by industry to test safety and determine the optimal dose to prevent skin cancer while balancing risk and benefit.

In addition, he said, “an urgent question involves absorption in infants and children, who have different ratios of body surface area to overall size and whose skin may absorb substances at differential rates.”

The Personal Care Products Council’s statement said the industry has offered “state-of-the-art toxicological safety approaches as alternatives” to the FDA’s testing method. “We look forward to our continued work with the FDA to ensure that consumers have access to products containing a broad variety of sunscreen active ingredients,” Kowcz said.

While science continues to answer questions about sunscreen, Califf and other experts call for the public to continue to protect their skin from the dangerous rays of the sun.

The Environment Working Group recommends choosing a mineral sunscreen containing titanium dioxide and zinc oxide when possible, while the American Academy of Dermatology recommends talking to a board-certified dermatologist if you are concerned about the safety of the sunscreen’s ingredients.

Both organizations say there are ways to protect yourself and your family other than sunscreen. Seek shade, especially between 10 a.m. and 2 p.m. when the sun is at its hottest, and whenever your shadow is shorter than you. Use protective clothing, such as long-sleeved shirts and pants and a hat with a wide brim, and don’t forget the sunglasses.

“It’s seeking shade, using clothes and when necessary using sunscreen,” Andrews said, “but not using sunscreen to prolong your time in the sun.”

Correction: A previous version of this story incorrectly stated which group recommends mineral sunscreens.