Better with it than without it. That’s the verdict of the U.S. Food and Drug Administration (FDA) grappling with the question as to whether sunscreens remain safe to use despite allegations on some of their chemical ingredients, such as oxybenzone can have undesirable health outcomes.

This latest flap concerning sunscreens was triggered by a study published in JAMA last May. The small study concluded there is a need for more research into the absorption of some sunscreen ingredients into the human body.

The JAMA study was run by the FDA. Involving only 24 participants, the study sought to determine the systemic exposure of active ingredients present in four commercially available sunscreens of different formulation types under maximal usage conditions.

These active ingredients were avobenzone, oxybenzone, octocrylene and ecamsule.

The study found systemic concentrations of more than 0.5 nanograms per milliliter (ng/ml) of all four active ingredients in the blood of these volunteers. This meant the plasma concentrations exceeded the threshold established by the FDA for potentially waiving some nonclinical toxicology studies for sunscreens.

Despite this dire sounding conclusion, there was no imminent danger from using sunscreens with these active ingredients.

“The systemic absorption of sunscreen ingredients supports the need for further studies to determine the clinical significance of these findings,” said the study. “These results do not indicate that individuals should refrain from the use of sunscreen.”

The loud public controversy triggered by this finding had forced the FDA to defend its conclusion.

It clarified these findings should be considered in the context of several limitations. It said the study is called an “exploratory maximal usage trial” (MUsT). The study was designated a MUsT because the sunscreen products were applied according to the maximum limit of the products’ directions for use. This length of time likely far exceeded use by the average consumer.

The FDA said while it recommends active ingredients in sunscreen that exceed 0.5 ng/ml should undergo toxicology testing to check for harmful health effects, this number is somewhat arbitrary because it isn’t known what the significance of this blood level means.

The FDA acknowledged that without further testing, we don’t know what degree of absorption should be considered safe.

It said it hasn’t asked the public to stop using sunscreens that contain avobenzone, oxybenzone, octocrylene, or ecamsule.

That’s because while the JAMA study concluded these ingredients were absorbed by the body when applied at high concentrations, they don’t know if this affects a person’s health.

The FDA reminds Americans that exposure to ultraviolet (UV) rays from the sun is a major risk factor for skin cancer. This is the most common type of cancer in the U.S. It said sunscreen use has been shown to protect against UV-induced skin cancers -- as well as sunburns and signs of aging.

Sunscreen
Skin received adequate protection from UV rays when participants applied sunscreen at a thickness of 2mg per cm2. Jean Beaufort/PublicDomainPictures