Do you know what forever chemicals are?

“Chemicals Forever” made headlines recently as new EPA regulations limit the amount of some species that can be present in drinking water.

Here, Carla Ng, associate professor of civil and environmental engineering at the University of Pittsburgh Swanson School of Engineering, explains what these chemicals are, where they occur and what is being done to limit them their effect.

What exactly are forever chemicals?

When scientists in the 1940s developed a chemical compound that could repel both water and oil, they believed it was a revolution in materials science. They weren't wrong.

This class of chemical compounds, called per- and polyfluorinated alkyl substances (PFAS), were quickly used to make useful household products like Teflon and dental floss, as well as industrial agents like Firefighting foam. They were even used in parts of the Manhattan Project.

Decades later, PFAS are still around. Due to their impressive surface density, these “forever chemicals” do not break down in the human body or naturally Naturecausing health concerns such as cancer, thyroid disease and reproductive disorders.

Ng has dedicated much of her career to investigating common sources of PFAS contamination and has worked collaboratively to create roadmaps that reduce unnecessary PFAS use, prevent worsening human and environmental exposures, and associated costs distribute more fairly.

Where can they be found?

Pretty much everywhere.

Ng explains that while society is more aware of the risks of PFAS than we were in the 1940s, the chemicals are still used extensively today for specialty firefighting foams, personal care products and food packaging, to name just a few applications.

“It’s hard to escape them,” says Ng.

The Environmental Protection Agency (EPA) reports that most people in the United States have been exposed to PFAS in some way. Exposure occurs when touching, eating, drinking or inhaling materials containing PFAS, often from drinking water, landfills, consumer products such as anti-stick agents or firefighting foam.

Ng recommends using the Environmental Working Group's interactive map, which tracks PFAS contamination across the United States. She notes that states with higher levels tend to have the most research behind them.

“Scientists still don't know how much PFAS has been produced globally, meaning important 'hotspots' of PFAS contamination are likely being missed,” says Ng.

How do scientists test for contaminants in drinking water?

Until this month, there was no national standard for maximum contaminant levels of PFAS, so individual states set their own. Pennsylvania, for example, set its maximum levels for PFOA and PFOS – both of which fall under the umbrella of PFAS – on January 14, 2023, at 14 parts per trillion for PFOA and 18 parts per trillion for PFOS.

The EPA has its own approved testing method drinking water and uses a certified laboratory. Ng's lab used a method called 1633 — still in development at the EPA — to understand how much contamination occurred when a small Pittsburgh community faced its own ecological disaster. Although it requires twice the amount of water compared to the EPA method, it is capable of detecting a wide range of PFAS compounds.

Can they be eradicated?

There was a time before PFAS was used and found for everything everywhere. We won't be going back to that any time soon.

“Even if we manage to stop the use of these PFAS chemicals immediately, the problem lies in their persistent chemical properties,” says Ng. “It will take a very long time until the environment is clean again.”

One question that stands between us and a future with permanently fewer chemicals is whether PFAS is necessary. Ng and other researchers have been trying to determine whether there are ethical, safe alternatives that would allow us to avoid using PFAS in some applications. It's possible to find a suitable replacement for non-stick pans and dental floss, but what about green technology, safety suits or medical devices?

“It is important that this is not permanent, and we need innovation to advance the development of replacements for these compounds,” says Ng.

There is still a gray area when it comes to disposing of household items containing these chemicals as they typically end up in landfills, creating a cyclical problem as regulations for PFAS are still coming to light.

At least at home, there are ways to limit the risk of infection. Both activated carbon granules and reverse osmosis filters can reduce the PFAS content in drinking water.