At least 24 sick after exposure to substance at Ohio prison

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At least two dozen people at a prison in Chillicothe, Ohio, became ill on Wednesday after being exposed to a substance that was possibly the powerful opioid Fentanyl, according to the Ohio State Highway Patrol.

Those affected by the substance at the Ross Correctional Institution were correctional officers, nurses and inmates, according to a release by state police.

A more detailed breakdown of who was affected was not immediately available, but initial reports said 15 guards, five nurses and one inmate showed signs of illness. It was unclear who else was exposed.

Police received a call at 9:10 a.m. ET about a substance exposure at the facility. All officers, nurses and inmates affected were responsive and transported to Adena Regional Medical Center for treatment, according to police.

Police said there had been no fatalities and there was no threat to the public.

State police said it was possible the substance was Fentanyl, a powerful synthetic opioid that can be absorbed through the skin, eyes or mouth, and can cause an overdose even in small doses, according to the Mayo Clinic. However, police did not immediately confirm to NBC News that the substance was in fact Fentanyl and said testing will have to be done to identify it

Narcan, a life-saving drug used to counter an overdose of Fentanyl, had been administered to several victims, according to police, and 300 doses of Narcan had been made available at Ross Correctional Institution.

The cellblock where the substance exposure happened had been cleared and all inmates and employees had been relocated to other parts of the facility.

Police said a hazardous materials decontamination team was headed to the prison to clean up the scene.

The incident remains under investigation.