A group of Democratic U.S. senators is calling on the federal government to immediately ban the use of a controversial device — only used in Massachusetts — that administers shocks to students with disabilities to control their behavior.

The group urged the U.S. Food and Drug Administration to finalize rules to ban the apparatus in a letter dated Monday and signed by eight senators, including presidential candidate Bernie Sanders.

Sen. Patty Murray, a Democrat from Washington, said in a press release that it is “unconscionable” to shock children and adults. The FDA missed a self-imposed deadline to issue a rule banning the device by the end of last year.

“We have an obligation to protect children and adults with disabilities from archaic and inhumane forms of punishment,’’ said Murray, the senior Democrat on the Senate Health, Education, Labor and Pensions Committee. “No more excuses, the FDA needs to finalize this rule immediately.”

A spokesman for the FDA said the agency received the letter and will respond directly to the senators.

The Rotenberg Educational Center in Canton is a privately operated, taxpayer-funded school that serves children and adults with disabilities. Officials from the center have long maintained that the shock devices are life-saving for a group of people who suffer from profound disorders that can cause severely aggressive and self-injurious behavior, like head-banging and biting.

But critics call the system torture. The FDA first proposed the ban in 2016. Two years later, then-FDA Commissioner Scott Gottlieb announced that the FDA planned to prohibit the devices, because they "present an unreasonable and substantial risk to public health."

Marie Washington, the president of the Judge Rotenberg Center Family Association said in a statement that the only alternative to controlling behavior through shocks for their children is "to drug them into being incapacitated."

"It is unfortunate that individuals with little to no knowledge of our children or the issues they face are putting them in danger of losing the only safe and effective treatment available to them," Washington said. "If you think we haven't explored and tried alternatives available to us, you underestimate our intelligence and the love we have for our kids."