If you're a consumer at Chipotle or Sweetgreen, you might feel virtuous that the bowls used there are considered compostable. However, new findings show that these compostable bowls can still cause harm to both the environment and human health.

Food writer Corby Kummer joined Boston Public Radio on Tuesday to talk about what this new research means for the future of your food bowl.

"A writer from The New Food Economy got 19 different samples of compostable bowls, from Chipotle to Sweetgreen. All of them had high content of fluorines, which is what these 'forever chemicals' contain," he said.

Compostable bowls began to find increasing popularity when some cities like New York banned Styrofoam containers, Kummer said.

"New York and others started banning single-use foam because it was so bad for the environment and it never biodegraded," he said.

These foam containers contained long chain PFAs, and switching to compostable materials seemed reasonable, Kummer said. Yet, these compostable containers consist of the less researched short chain PFAs, he added.

"What they didn't know is that all these short chain PFAs make compost toxic, because they never dissipate and they are long persistent in the human body and collect in your organs," Kummer said.

The reason that PFAs are useful in food containers lies in their ability to resist liquid, preventing food from dripping through its holder, Kummer noted. "PFAs are used to resist water in cookware and carpets. The long forms [of PFAs] were ruled out for a lot human use, but there's no data on the shorter forms."

A new law will go into effect in 2020 banning all PFA use in single-use serviceware in San Franciso. With this in mind, alternatives containers will be produced, Kummer said.

"All sorts of manufacturers are racing to provide alternatives, since San Francisco will outlaw short form PFAs in January," he said. "Sweetgreen was the first to step up and say, 'Yes, we're looking into alternatives and we're going to find a way around this.'"

Kummer is a senior editor at The Atlantic, an award-winning food writer, and a senior lecturer at the Tufts Friedman School of Nutrition and Policy.