EPA Says Even Extremely Low Levels of PFAS in Drinking Water May Be Unsafe

Up until this point, the EPA has had only interim health advisory levels for two PFAS known to be harmful: PFOA and PFOS. Those levels were set at 70 parts per trillion (combined)—many times higher than what evidence suggests is safe, Philippe Grandjean, PhD, a professor of Environmental Medicine at the University of Southern Denmark and an expert on PFAS health risks, told CR in a previous conversation.

The EPA’s updated interim levels are much, much lower. The agency set the health advisory level for PFOA at .004 parts per trillion and for PFOS at .02 parts per trillion, an indication “that some negative health effects may occur with concentrations of PFOA or PFOS in water that are near zero,” according to the EPA.

This could create concern amongst water suppliers about whether these levels can be met with current technologies used to treat and filter drinking water, according to DeWitt. While these two PFAS have been mostly voluntarily phased out of production in the U.S., they’re still widely found in the environment, in people, and in various products, including food packaging.

The EPA also established health advisory levels for two other PFAS: GenX chemicals—often used as a replacement for PFOA—and PFBS, a replacement for PFOS. These levels were set at 10 ppt for GenX and 2,000 ppt for PFBS.

The PFBS level is higher than expected based on available science and above the safe level already established by certain states, according to a statement from Erik Olson, senior strategic director for health and food at the National Resources Defense Counsel. In Michigan, for example, drinking water cannot contain more than 420 ppt PFBS.

But the levels for PFOS, PFOA, and GenX reflect science showing that “these chemicals are shockingly toxic at extremely low doses,” Olson said. 

Health advisories are not enforceable limits, and, on their own, they "are not enough to protect public health from the many human health impacts associated with PFAS exposures," says Julia Varshavsky, PhD, an assistant professor of environmental health at Northeastern University, who manages a database that includes over 1,000 studies that have looked at the health and toxicological effects of PFAS. But they are meant to “inform public health decision-makers and state agencies about the adverse human health impacts of contaminants like PFAS in drinking water, for which there is ample human and experimental data.” State and local regulators may use these levels to guide monitoring for PFAS, inform residents about PFAS contamination, and to try to take steps to reduce exposure to these chemicals. 

While setting these health advisories is a first step, EPA “now must set legally enforceable limits that are based on these levels,” Ronholm says. 

The EPA says it plans to propose a PFAS National Drinking Water Regulation in the fall of this year—which could set those legally enforceable limits—though it’s not clear how quickly they’d go into effect.

Because of the many useful properties of PFAS, they’ve long been used in a variety of settings and products. They’re found in nonstick pans, firefighting foam, and in many products meant to be grease, water, or stain resistant, like outdoor gear, carpets, clothing and bedding. As a recent CR investigation documented, they’re often found in takeout food packaging too, like burger wrappers, salad bowls, and sandwich boxes.

People can be exposed to PFAS by using these products. But even if you were able to avoid products made with PFAS, their production and eventual disposal ends up contaminating soil, air, and drinking water, with PFAS building up over time since they generally don’t naturally break down.

In recent years, researchers have documented a number of harms associated with exposure to PFAS, including liver damage, increased risk for certain cancers, kidney disease, thyroid disease, and a weakened ability for the immune system to fight infections. (See our story on how PFAS can harm your health.)

With the growing body of research on these health hazards, health and consumer advocates have called on federal agencies to do more to reduce harmful exposure to these chemicals. In the fall of 2021, the EPA announced it would be taking action to improve the safety of drinking water, which is one of the most important sources of PFAS exposure for many people.

While experts praised the EPA’s action on these four PFAS, many say it falls short, as it does not address the thousands of other PFAS. These other PFAS are often used as substitutes for more restricted chemicals, but may cause similar health effects to those known to be harmful.

“There are so many PFAS beyond the four that EPA addressed through the [health advisories], including thousands for which we have sufficient evidence to support the idea they should be regulated as a class,” Varshavsky says. Regulating PFAS as a class would mean federal regulations designed to address PFAS as a broad category, instead of looking at individual chemicals one by one.

Plus, Varshavsky notes, EPA action on drinking water doesn’t affect other potential sources of exposure to PFAS, like food packaging, dental floss, and diet.

“We cannot continue taking a ‘whack-a-mole’ approach to the ever-expanding avalanche of 12,000 PFAS chemicals,” Olson said in his statement. “It’s time to regulate all PFAS with enforceable standards as a single class of chemicals. Any other approach will leave every one of us at risk from these forever toxics for decades to come.”