A Globe review of complaints against the Judge Rotenberg Educational Center shows that the state is investigating 10 claims made in the past six months that electric shocks delivered to misbehaving students caused burns on their arms, legs, or torsos. Though none of the claims has been proven, the Disabled Persons Protection Commission has forwarded the case of a child who allegedly had multiple burns to the Norfolk County district attorney for criminal investigation.

Officials at the controversial Canton school say the skin shocks are similar to bee stings, a painful but harmless way to prevent severely disabled people from hurting themselves or others. They say the devices that deliver the shocks , called graduated electronic decelerators, or GEDs, have never injured anyone, let alone burned them. The school's enemies make burn allegations, they say, to make the Rotenberg Center look bad.

But at least four former employees said in interviews that burns are so common that the devices must sometimes be removed to let injuries heal, breaks that the staff calls ``GED holidays." And the state of New York, which provides two-thirds of Rotenberg students, this month asked the US Food and Drug Administration to investigate the safety of the devices after investigators met a student who said she was burned by a shock administered while she was taking a shower.

``We need a team of investigators" to handle all the complaints against the Rotenberg Center this year, said Nancy Alterio , executive director of the Disabled Persons Protection Commission, where 22 abuse complaints have been filed in 2006 compared with nine in the preceding six years combined.

The rising number of complaints against the Rotenberg Center, which parents often turn to as a last resort for their children after less drastic methods fail, comes as the Legislature debates a proposed ban on the use of shocks on students. The Senate included the ban in the state budget now being negotiated, but House of Representatives budget negotiators have balked, in part because of a legislator whose nephew is a Rotenberg student.

``My nephew's case is the most severe that you could possibly imagine," said Representative Jeffrey Sanchez of Boston, explaining that the autistic and mentally retarded young man deliberately vomited up and re-swallowed his food, burning his esophagus with stomach acid. Since he began shock treatment, he regurgitates far less, said Sanchez. ``My brother . . . feels that the Rotenberg Center is the only thing that has kept him alive."

But Senator Brian Joyce of Milton, who is leading the effort to ban shocks, points out that no other school in the country routinely shocks students and that taxpayers foot the $227,000 a year tuition for students to attend the residential school. ``This is not only embarrassing, it is wrong," he said.

The shock devices have generated controversy ever since Rotenberg employees developed them in the early 1990s to deliver two-second electric jolts to the skin. Previously, the school had used a commercially available electroshock device called SIBIS, for ``self-injurious inhibiting system," but Rotenberg officials wanted to be able to administer a stronger shock to discourage dangerous behavior. The GED delivered a shock that was at least twice as powerful and lasted 10 times longer than SIBIS.

Medical specialists found that the GED was safe as long as the electrodes weren't applied to the chest, spine, or other sensitive areas. In 1991, the Food and Drug Administration permitted Rotenberg officials to use the devices on students partly on the basis that the GED was similar to SIBIS, which already had FDA approval.

New York officials now say that the Rotenberg Center exaggerated the level of FDA oversight, making it seem as if they had gone through a full FDA review when the FDA had simply ``registered" the GED for use at the school. ``We accepted certain representations by the school about the device being approved," said New York's deputy education commissioner, Rebecca Cort . ``Only when we requested much more in-depth information did we identify" the fact that the FDA had not formally approved the device, she said . Rotenberg officials say they never misled anyone and fully comply with FDA rules.

Rotenberg officials also say they take many precautions such as requiring staff to periodically move electrodes, which students wear 24 hours a day, to prevent burns. They said they have safely applied the GED to more than 400 students, including 40 who have received shocks from a more powerful device that carries triple the shock of the regular GED.

However, from 1992 until last year, state investigators identified 10 occasions when students received shocks when they had done nothing, either because the device malfunctioned or the staff accidentally shocked the wrong person. Most of the complaints were dismissed because the injuries weren't serious enough, but the Disabled Persons Protection Commission determined that the school abused one student who received five to 10 spontaneous shocks due to a malfunction.

Commission records also show that one student was seriously injured as a result of shocks. The man was admitted to Children's Hospital in Boston in 2002 with ``acute stress response" after receiving 30 shocks while strapped to a board for six hours. Witnesses told investigators the student stopped eating and drinking afterward and cried about his punishment, but investigators dropped the complaint because the shocks were part of a court-approved treatment plan.

Until this year, there were only a few allegations that the GEDs burn students, which the school's attorney, Michael Flammia , argues is proof that burns do not happen. ``It's a pretty simple thing to investigate. You come in and examine the students," Flammia said. He said state troopers investigating burn complaints for the commission ``found no problems at all" at the school.

The 10 burn complaints filed with the commission this year are anonymous, but former teachers say employees account for several of them.

``I have personally seen the burn marks," said a former teacher who asked that his name not be used. ``A lot of it is caused by inexperienced staff. . . . It's a common mistake that these devices aren't put on properly."

Scott Allen can be reached at allen@globe.com.