(Reuters) - A Massachusetts school for the developmentally disabled, and parents of its students, on Friday urged a federal appeals court to overturn a federal ban on its controversial use of electric shock devices to correct aggressive or self-harming behavior in adults and children.

Max Stern of Todd & Weld, arguing for the parents, and Michael Flammia of Eckert Seamans Cherin & Mellott, for the Judge Rotenberg Educational Center, told the D.C. Circuit U.S. Court of Appeals Friday that the U.S. Food and Drug Administration ban exceeded the agency's authority by regulating the practice of medicine.

The U.S. Justice Department's Daniel Aguilar, representing the FDA, countered that the ban fell under the agency's power to ban the manufacture, distribution or promotion of "adulterated" devices.

The panel – Chief Judge Sri Srinivasan and Circuit Judges David Sentelle and Gregory Katsas – appeared skeptical of the Aguilar's argument, repeatedly pressing him to explain how the FDA could ban a particular use of a device but not the device outright.

"We really do have an issue as to whether or not you're interfering with the practice of medicine," Sentelle said.

The FDA announced the ban on the use of electric shock devices to treat aggressive or self-harming behavior last March. Rotenberg, the only facility in the U.S. that manufactures and uses such devices for that purpose, had drawn harsh criticism from disability rights advocates, who said the practice could cause severe psychological and physical injuries.

The ban relied on a statute that gives the FDA the authority to pull unreasonably dangerous devices off the market. That authority has been used only twice: once for a type of hair implant and once for the use of powdered gloves in surgery.

While the powdered glove ban similarly targeted a particular use of a device, it was never tested in court.

Rotenberg and a group of parents and guardians petitioned the D.C. Circuit to overturn the ban, arguing that the shock treatment was beneficial for patients who did not respond to any other treatment.

They also said that the banning statute did not give the FDA the authority to ban one use of a device, noting that the ban still allowed the use of shock devices as a voluntary aid for quitting smoking or nail-biting.

Stern said Friday that it was unreasonable for the FDA to ban the device "even for these persons who have nothing else."

Flammia said the device was not hazardous, but "unpopular with advocates," and that some patients were "thriving" and "deserve to keep their lifesaving treatment."

Most of the argument focused on the FDA's authority. Aguilar conceded that the agency could not directly regulate how doctors used devices they already have, but said that, after the ban, the agency could go after Rotenberg for distributing adulterated medical devices.

In rebuttal, Stern said that the ban's "obvious intent and purpose" was to stop Rotenberg from using the devices.

The panel did not indicated when it would rule.

The case is The Judge Rotenberg Educational Center Inc v. FDA, D.C. Circuit U.S. Court of Appeals, No. 20-1087.

For parents petitioners: Max Stern of Todd & Weld

For the school: Michael Flammia of Eckert Seamans Cherin & Mellott

For the FDA: Daniel Aguilar of the U.S. Department of Justice