In the 1960s, researchers from the U.S. Navy Research Laboratory began testing a new class of firefighting foam that could rapidly extinguish fuel fires.
The foams, dubbed aqueous film-forming foam (AFFF), were a boon to firefighters. Special perfluorinated chemicals gave AFFF unique hydrophobic and surfactant properties, allowing it to rapidly seal over burning fuel and prevent reignition once a blaze had been extinguished. By the 1970s, AFFF was in use at most military bases, airports, refineries, and many civilian fire departments around the world.
Over the next several decades, AFFF was used to both fight actual fires and to train firefighters on practice fires. It often was left to soak into the ground after use. AFFF is still in use today.
Flash forward to 2020, and we now know that the same chemicals that give these firefighting foams their unique properties have become a major global source of drinking water contamination. These chemicals, called per- and polyfluoroalkyl substances (PFAS) have been detected in water supplies across the country—and in our bodies. In fact, the Environmental Working Group estimates that PFAS chemicals are detectable in all major U.S. water supplies. CDC scientists have found four PFAS chemicals in the blood of nearly all Americans tested, indicating “widespread exposure to these PFAS in the U.S. population.”
They’re often called forever chemicals, “because there’s no indication that they will biodegrade in the environment, as they are extremely stable and persistent with a potential for them to be permanently present and cycling around the environment,” Ian Ross, a PFAS contamination expert for Arcadis, a Netherlands-based engineering and consulting firm, told EHN.
PFAS have been linked to a slew of health issues, including hormonal changes, decreased fertility, weakened immune system response and increased cancer risk.
Studies suggest that firefighters have higher levels of these chemicals in their bodies than the general public. A study of female firefighters, published in the journal Environmental Science & Technology in February, found that those who used firefighting foam in the past year had higher concentrations of PFAS in their blood than those who had not.
In light of mounting liability risk, state and local bans on PFAS-containing products, and pressure from various groups over environmental and health concerns, many fire departments, municipalities, and private companies now are looking to switch to PFAS-free foams. The adoption of PFAS-free firefighting foams in the U.S. is relatively new. In 2018, Washington became the first state to ban PFAS-containing foams for most firefighting uses. Several other states have since followed with similar legislation.
Making sure these new foams actually are safer for the environment and health than the ones they replace is key to ensuring we don’t end up in the same place 50 years from now—with widespread contamination from a new set of toxic chemicals—say environmental health experts.
There’s promise on this front, with a number of states taking action to ban or phase out PFAS-containing foams and a new certification program helping fire departments and businesses identify safer foam products, but hurdles remain at the federal level.EHN