But what are PFAS? How do they work? Where were they found? Should we be concerned? Let’s take a look.

What is a PFAS?

PFAS stands for “per- and polyfluoroalkyl substances,” which is a string of words and part-words that means basically nothing to almost everyone. They’re a group of more than 500 synthetic chemicals which were largely used in the past for certain qualities; they’re extremely resistant to water and stains. 3M used to make them for packaging; today they’re found in stuff like that foam firefighters use. What makes them problematic is not that they’re incredibly popular, but rather that they are extremely durable. Sometimes known as “forever chemicals,” they stay in the environment—in the air, water, in plants, in the bodies of humans and animals—for a very, very long time.

Are they dangerous?

Well, good question. Information on how exactly PFAS affects human health is not as thorough as for many other chemicals, even similar ones. The CDC has a page that notes that some studies have found that PFAS may stunt growth and learning in children; may affect the immune system; may increase the risk of cancer; and may interfere with hormones, including the ability to become pregnant.

PFAS also build up in the body, sort of like heavy metals like arsenic. It’s not a single fatal dose that’s the concern; it’s a steady ingestion of these materials over a lifetime.

What did the FDA find?

The Environmental Working Group revealed some FDA documents that showed the FDA had found PFAS in various foods, including dairy, meat, fruits, greens, and, in its highest quantities, chocolate cake with icing. A week later, the FDA released a document saying those leaks were accurate, but that the levels found do not pose a safety risk for humans. It also says that the FDA does not believe that PFAS are a safety concern “based on the available current science.”

The EWG, in a response, says the FDA is wildly underreacting to their own findings, and that there is “growing evidence” that PFAS levels are causing harm to people. “FDA should be fighting to reduce our exposure to toxic PFAS, not papering over the risks,” wrote the EWG’s senior scientist, David Andrews.

Who is most at risk?

Aside from children, the riskiest geographic areas seem to be places near military sites and airports. Those locations frequently use the fire-fighting foams that contain PFAS, which then sinks into the air, soil, and water supply—and in turn into, just for example, milk and pineapples.

What’s being done?

Though the FDA, at least in the view of the EWG, seems to be playing down the risk of PFAS, not all agencies have done the same. The EPA, earlier this year, started down the path of figuring out how to deal with PFAS in groundwater by asking for public input on potential action.

The FDA, for its part, calls its findings “a benchmark to use as we continue our critical work studying this emerging area of science.” The Agency says it is “committed to testing more foods, collaborating with other federal agencies, helping states develop their own testing capacities, and continuing to support responses to contamination events.”