Why the FDA won't approve chemicals used in Europe's better sunscreens

A recent article published in Chemical & Engineering News (C&EN) decried the FDA’s unwillingness to approve eight chemicals found in European sunscreens that could help prevent melanoma and other skin cancers.

In the article, author Marc S. Reisch, explains:

Most sunscreen actives protect users against UV-B rays with wavelengths between 290 and 320 nm, the primary culprits in sunburn. Some also protect against UV-A rays in the 320- to 400-nm range, which can penetrate more deeply into the skin and cause cancer.

He writes that of the chemicals approved for use in sunscreen by the FDA, only two provide good protection against UV-A rays. Four of the unapproved European chemicals, however, would provide some level of UV-A protection.

So what’s the deal?

Reisch explains that the hold up can be blamed, in part, on the differing standards for testing the chemicals in question: amiloxate, bemotrizinol, bisoctrizole, drometrizole trisiloxane, ecamsule, iscotrizinol, octyl triazone, and enzacamene. Europe considers sunscreen a cosmetic, and tests ingredients for it as such, while the FDA treats sunscreen as an over the counter medication. That means the FDA’s standards for chemicals used in sunscreen are different—and stricter.

Frustration over the FDA’s slow pace prompted Congress to pass the Sunscreen Innovations Act (SIA) in November 2014, which instructed the FDA to, among other things, cap the review of sunscreen ingredients to 300 days. Considering how some drugs having been waiting for approval since as far back as 2002, this is an improvement.

In a blog post from February 2015, the FDA’s Theresa M. Michele wrote that the agency had indeed taken a second look at the eight chemicals and decided against approving six. She said:

On January 7….  we announced our tentative determinations that six of these ingredients are not [generally recognized as safe and effective] for use in sunscreens because we need more data from the manufacturers to help establish the safety and effectiveness of these products.

The other two chemicals were later also declined FDA approval. Ultimately, Michele explained, the FDA needed to feel confident that the new chemicals wouldn’t cause negative health consequences in the long run. At this point, the agency does not.

This is not the first time the FDA has heard complaints about their reluctance to approve the chemicals. Critics like Reisch seem to argue that the FDA’s excess of caution, at best, or bureaucratic ignorance, at worst, is preventing Americans from accessing the protection that might save them from melanoma.

But there is something to be said for the federal agency’s hesitation: According to the nonprofit Environmental Working Group warned that, according to a 2012 study, one of the chemicals under review—enzacamene—could affect fetuses:

… laboratory tests suggest that 4-MBC disrupts the hormone system (Krause 2012). Hormone disruptors pose particular dangers to the fetus because small perturbations to hormone systems could cause lasting changes in the developing brain, thyroid and reproductive system.

The other chemicals don’t have comparable warnings. But if the FDA sticks to their guns, we likely won’t be seeing them in our sunscreen anytime soon.

Danielle Wiener-Bronner is a news reporter.