The world’s only known school for children and young adults with special needs that inflicts electric shocks to control their behavior is facing international pressure to have the controversial practice banned.

For almost three decades the Judge Rotenberg Center in Canton, Massachusetts, outside Boston, has been zapping many of its special-needs residents with a custom-designed electric shock machine known as the GED. Students are required to carry the devices in backpacks that deliver charges of up to 41 milliamps – 10 times the amperage used in most stun guns – to their legs, arms, hands, feet, fingers or torsos via electrodes on the skin.

The shocks, administered by staff using remote controls and lasting up to two seconds, are intended to cause pain that will discourage the students from indulging in harmful or dangerous behavior. The school categorises the punishment as “aversive therapy” which it claims can help seriously troubled individuals avoid life-threatening injury, having been beyond the reach of other care regimes.

A coalition of advocacy groups led by Disability Rights International have written this week to the human rights arm of the Organisation of American States (OAS), based in Washington, to request urgent action. The coalition is calling on the pan-American authority to demand that the US, which is one of its 35 member states, impose a federal ban on the method.

The petition argues that JRC’s use of electric shocks, in combination with restraints and isolation rooms, “constitute[s] cruel, inhuman and degrading treatment and torture”. It cites the work of Juan Mendez, the UN’s former special rapporteur on torture, who in that role in 2013 released a report that concluded that the “rights of students of the JRC subjected to electric shocks and physical means of restraints have been violated under the UN convention against torture”.

Mendez told the Guardian this week that he had hoped that the practice would have been prohibited by now. “The use of electric shocks to control the behavior of children inflicts pain and suffering that at least rises to the level of cruel and degrading treatment and in some cases is definitely torture. That is prohibited by state, national and international law.”

Laurie Ahern, president of DRI and the lead author of the new petition, said the use of electric shocks amounted to “state-sanctioned child abuse. It’s torture. That wasn’t acceptable in Guantánamo Bay, but it’s apparently acceptable in a special-needs school in Massachusetts.”

Ahern said she hoped that stern intervention by the OAS would compel the US government to take action over a contentious practice that had continued for many years. “The American government should care deeply about a form of torture applied to vulnerable children on US soil.”

Under the articles of the human rights commission of the Organization of American States, the commission can issue what are known as “precautionary measures” that demand that member states take immediate action to prevent violations. Such measures can kick in whenever there is a “grave and urgent situation that presents a risk of irreparable harm” to people.

The GED pack used to inflict electric shocks on residents. Photograph: Rick Friedman/The Guardian

JRC currently has 47 of its 275 clients under “aversive treatment”. In each of those 47 cases, the use of shocks has to be approved in advance by a Massachusetts probate and family court, with an attorney assigned to represent the individual’s interests.

In 2010 the Guardian was granted exceptionally rare media access inside the school. A tour of the institution, with its bright pink and green walls and 6ft-high models of Bugs Bunny and the Wicked Witch of the West, was given by Matthew Israel, a psychologist with no medical training.

Israel came up with the idea of a punishment regime for children when he read a novel called Walden Two. The book described a fictitious utopian community in which positive behavior is encouraged and negative behavior thwarted.

From that kernel of an idea Israel began applying “aversives” on vulnerable children from 1971. Initially he began with spanking with spatulas, pinching and dousing kids with water, and from the early 1990s he switched to electric shocks, going to the lengths of designing his own electricity generator that he called the Graduated Electronic Decelerator (GED).

It wasn’t acceptable in Guantánamo Bay, but it’s apparently acceptable in a special-needs school in Massachusetts Laurie Ahern, DRI

For some students, Israel told the Guardian, the GED devices had to be worn long-term. He compared it to wearing glasses or hearing aids. When the Guardian visited the center one of its residents, Brandon, had been living there for 22 years and was still being shocked on average 33 times a week.

In a detailed statement to the Guardian, JRC said that its treatment was designed to help children and adults who engage in the most dangerous aggressive and self-injurious behaviours such as head banging, eye gouging, tearing their own flesh, biting off body parts and pulling out their own teeth. Clients came from 15 states including Massachusetts, New York, Illinois and California as well as DC and the Virgin Islands.

JRC said its residents “could not be effectively treated with other forms of treatment” in other centers that included “massive dosages and combinations of powerful anti-psychotic medications which have dangerous and sometimes permanent side-effects, including death”.

The statement highlighted the close monitoring that is given to students. All rooms in the center are surveilled with a video monitoring system that is observed around the clock in a central administration building.

JRC insisted that the use of pain was safe and effective. “The use of electronic stimulation devices (ESDs) causes a rapid deceleration of students’ dangerous and disruptive behaviors and JRC’s educational program teaches these students to replace their problematic behaviors with positive behaviors such as social, recreational, and educational activities. The benefits of using the devices strongly outweighs any potential risks.”

It also insisted that the use of aversive interventions was “widely accepted by professionals as necessary”. But that conflicts with the almost universal consensus among disability groups that such techniques were unacceptable and could be replaced with positive therapies.

Wendy Fournier, president of the National Autism Association, told the Guardian: “I can’t believe that this place is still open. It should have closed years ago – for how many years have advocates been fighting against this so-called treatment? It’s mind-boggling.”

Over the years JRC has come under persistent legal fire and endured multiple scandals. In 2007, staff at one of its residential homes received a call from a senior manager instructing them to administer shocks to two badly behaved students aged 16 and 19. Over the following three hours, one of the boys was given 77 shocks, the other 29. It was later revealed that the initial phone call had been a made not by a manager but by a prankster.

In the wake of that incident, Israel was forced to resign as head of the school and sentenced to five years’ probation. Despite his departure, the electric shocks have continued.

In 2012, in the course of civil trial, video footage was released that showed an 18-year-old student, Andre McCollins, being shocked 31 times over seven hours as he was strapped face down on a board. He is heard in the video screaming and imploring “that hurts, that hurts” as the GED is activated, causing burns on his skin.

Various authorities have made repeated efforts to ban the shocks, with only limited results. In 2016 the US Food and Drug Administration, which has regulatory responsibility over therapeutic devices, announced that it proposed banning all electric shock machines “used for self-injurious or aggressive behavior because they present an unreasonable and substantial risk to public health”.

The FDA said the application of shocks could induce “significant psychological and physical risks … including depression, anxiety, worsening of self-injury behaviors and symptoms of post-traumatic stress disorder, pain, burns and tissue damage”. Yet still today the federal agency has not followed up on is proposal to implement a ban.

Massachusetts state authorities have also tried to restrict the use of the machines to fewer, closely regulated cases. But in June a family court judge stepped in and ruled that the activities of the center were legal and must be allowed to continue.

The state’s attorney general intends to appeal the ruling.