New Method Can Completely Destroy “Forever Chemicals”

A new combination of reactions can fully defluorinate per- and polyfluoroalkyl substances (PFAS) — commonly known as forever chemicals — from fire suppressant foams.

PFAS are a suite of chemicals containing carbon-fluorine bonds, which are extremely resistant to breakage. The properties of these bonds make PFAS a common candidate for high-heat applications, ranging from coating cooking pans to making fire suppressant sprays for fuel conflagrations. But these chemicals also fail to degrade in the environment, and can build up in soil, water, and food.

A 2015 study published in the International Journal of Environmental Research and Public Health found PFAS in the blood of 97% of Americans. Animal studies have linked PFAS to liver damage, cancer risk, birth defects, and damage to the immune system.

Breaking down PFAS is a challenge both because of the strength of carbon-fluorine bonds and because the chemicals are often found contaminating water or in a mix of other chemicals, such as in fire suppressant foam, says Yang Yang, an assistant professor of civil and environmental engineering at Clarkson Univ. “You need to selectively pick the molecule out and then destroy it,” Yang says.

What’s more, firefighting foams — known as aqueous film-forming foams (AFFFs) — are difficult to work with, due to their propensity to balloon into masses of bubbles at the slightest agitation. Yang and his colleagues wanted to tackle this challenge and find a way to successfully break down these foams, which are...