Forever Just Got Shorter

 A team of scientists has found a cheap, effective way to destroy so-called forever chemicals, a group of compounds that pose a global threat to human health.

At the end of a PFAS molecule’s carbon-fluorine chain, it is capped by a cluster of other atoms. Many types of PFAS molecules have heads made of a carbon atom connected to a pair of oxygen atoms, for example.

Dr. Dichtel came across a study in which chemists at the University of Alberta found an easy way to pry carbon-oxygen heads off other chains. He suggested to his graduate student, Brittany Trang, that she give it a try on PFAS molecules.

Dr. Trang was skeptical. She had tried to pry off carbon-oxygen heads from PFAS molecules for months without any luck. According to the Alberta recipe, all she’d need to do was mix PFAS with a common solvent called dimethyl sulfoxide, or DMSO, and bring it to a boil.

“I didn’t want to try it initially because I thought it was too simple,” Dr. Trang said. “If this happens, people would have known this already.”

An older grad student advised her to give it a shot. To her surprise, the carbon-oxygn head fell off.

It appears that DMSO makes the head fragile by altering the electric field around the PFAS molecule, and without the head, the bonds between the carbon atoms and the fluorine atoms become weak as well. “This oddly simple method worked,” said Dr. Trang, who finished her Ph.D. last month and is now a journalist.

she started testing a number of chemicals until she found one that worked. It was sodium hydroxide, the chemical in lye.

When she heated the mixture to temperatures between about 175 degrees to 250 degrees Fahrenheit, most of the PFAS molecules broke down in a matter of hours. Within days, the remaining fluorine-bearing byproducts broke down into harmless molecules as well.

Dr. Dichtel and his colleagues are now investigating how to scale up their method to handle large amounts of PFAS chemicals. They’re also looking at other types of PFAS molecules with different heads to see if they can pry those off as well.

“It’s a huge challenge, but it’s in our grasp,” he said.