Author(s): Jesse Roman. Published on July 22, 2022.

Above: Firefighters in Germany use foam on the wreckage of a passenger train. Studies have shown that foams containing PFAS chemicals remain in the environment indefinitely after they are released, potentially contaminating water supplies and affecting the health of humans and animals.  GETTY IMAGES

The PFAS Problem

The old foam worked, but at a potential cost to human health and the environment


In the early 1960s, the US Navy began working with the chemical company 3M to develop a firefighting foam that could quickly extinguish liquid fuel fires aboard its ships, including aircraft carriers. Researchers for the project eventually stumbled across a promising new substance and in 1966 the Navy received a patent for aqueous film forming foam, or AFFF. Three years later, all Navy facilities were required to have AFFF on hand in the event of a fire. Varying forms of the original recipe have been widely used on military bases, airfields, oil and gas facilities, and by municipal fire departments ever since.

Starting as far back as the 1970s, however, scientists and health experts have raised concerns about the potential hazards of a group of chemical compounds inside AFFF, called per- and polyfluoroalkyl substances, or PFAS. The compounds are hardly unique to firefighting foams—an estimated 9,000 different types of PFAS compounds have been used since the 1950s in a range of products, from nonstick cookware to stain-resistant fabrics to takeout pizza boxes. Although their molecular makeup can vary slightly, all PFAS chemicals consist of chains of carbon atoms bonded to fluorine. These carbon/fluorine bonds, it turns out, are stronger than any chemical bond found in nature, to the point that they do not break down in the environment or even in the bodies of people and animals. This trait has led the US Environmental Protection Agency to describe PFAS as “forever chemicals.”


Studies have shown that wherever AFFF is extensively used and not recaptured—be it in training, in a fire, or washed down a drain in a fire truck bay—the PFAS compounds it contains tend to remain. The compounds have found their way into water supplies and soils; PFOS and PFOA, the two PFAS compounds that were most commonly produced in the US and therefore have been studied most extensively, have been found in air samples, oceans, and even the Arctic. Environmental Working Group, a Washington, DC, nonprofit, tracks and maps PFAS contamination in the United States. As of October 2021, it listed more than 2,800 locations in 50 states and two US territories that are known to be contaminated with PFAS. Between 2013 and 2015, the EPA conducted an extensive survey of US public water systems and found that 198 of them—or about 4 percent of all the nation’s public water systems—detected at least one or more PFAS chemical at or above the minimum reporting threshold. 

The pervasive nature of the chemicals has impacted the health of humans and wildlife alike, according to government and university studies conducted around the world. In 2007, researchers tested blood serum samples from about 2,100 people from across the US and found that more than 98 percent of the samples had detectible levels of PFAS. According to the Agency for Toxic Substances and Disease Registry, exposure to elevated levels of PFAS could cause increased cancer risk and other health issues in humans. Some of the non-cancer health problems with suspected links to PFAS include elevated cholesterol, thyroid disease, liver and kidney damage, effects on fertility and low birth weight, and immune suppression, according to various studies.

“We all thought it was completely safe—the warnings I read through the years said don’t drink it and don’t get it in your eyes because it stings, but it was not something we would suit up for or take any extraordinary precautions around,” said Jeremy Souza, a longtime firefighter and former deputy fire chief at T.F. Green International Airport in Providence, Rhode Island. Years ago, Souza and other firefighters used the AFFF solution in a variety of applications, including as an all-purpose de-greaser. “Now I have retired colleagues whose attitude I would describe as outright fear. For those of us who essentially bathed in it for decades, I’m concerned about what exactly I’ve been exposed to.”

JESSE ROMAN is senior editor at NFPA Journal. Top photograph: GETTY IMAGES