E-cigarette company executives faced questions this week from a congressional committee on their role in the teen vaping epidemic, ABC News reports.

Members of the House Energy and Commerce Committee questioned the CEO of Juul and other e-cigarette companies about flavored nicotine products still on the market after the Food and Drug Administration banned sweet and mint flavors for cartridge-based vaping products. Menthol and tobacco flavors are still on the market, as are single-use disposable devices.

The CEOs of NJOY and Fontem U.S. told the committee they had no data that indicates their flavored disposable products are being used by many young people.

Stanford University pediatrics professor Bonnie Halpern-Felsher told ABC News that teachers and students in the schools she works with say a growing number of teens are using single-use e-cigarettes. “Overwhelmingly in the last six months, what we hear is Juul, yes, but really it’s these disposables, and they don’t even say disposables, these educators and the students will say Puff Bar,” she said.