NEW CASTLE – New Castle City Council president Tom Smith, who sought treatment after opening a letter containing a white powder during Tuesday night’s caucus meeting, reported his hospital test showed traces of fentanyl in his system.

Smith had opened a letter just before council’s caucus meeting, when what he described as a “puff” of white powder came out of the envelope. The envelope contained a letter that had a person’s name and return address from Sharpsville, but was postmarked in Atlanta. The envelope was addressed to Smith and Councilwoman MaryAnne Gavrile.

Fentanyl is a powerful narcotic used as a pain-killer and an anesthetic. It has been associated with overdoses when added to heroin.

“We are definitely treating this as a credible threat until we can prove otherwise,” New Castle fire Chief Mike Kobbe said.

New Castle police Chief Bobby Salem said he has enlisted the help of the FBI to investigate the actual source of the letter. The powder has been packaged and sent to a lab for forensic testing and identification, Salem said.

Another council member reported feeling numbness of the lips but said those symptoms had subsided by Wednesday morning, Kobbe said, adding that anyone who was in the council chambers at the time should have been aware of any possible symptoms for 24 hours.

Smith went to the hospital on his own after the incident, which prompted the evacuation of city hall and pre-empted the caucus meeting.

Prior to a public hearing Tuesday night, Smith opened mail, left by the city’s clerk, at his desk in council chambers. When Smith opened the letter, a white “puff” came out and he immediately closed the envelope. Gavrile asked for gloves and a plastic bag, while Smith cleaned the desks with disinfecting wipes.

Council continued the meeting and called police. Smith, Mayor Chris Frye and Solicitor Ted Saad briefly left the meeting to talk in the hallway before Smith recessed the meeting, citing a police recommendation. New Castle police and fire departments and Lawrence County Department of Public Safety were summoned around 6:30 p.m., Kobbe said.

“They notified us, and we told them to evacuate the building, leave everything as it is and don’t leave the property,” Kobbe said.

The Department of Public Safety has a spectrometer that uses a laser to determine the chemical compound of a substance, Kobbe explained.

“When we arrived, the city security officer had put the envelope and its contents in a plastic bag and he zipped it shut and took it outside,” he said. “When our techs approached the envelope, there was not enough inside to obtain a large enough sample to determine the composition of it. We passed it off to Chief Salem, who took the package into evidence. As soon as he gets information from the lab, we’ll have a better direction,” Kobbe said.

The department had decontamination and hazardous materials equipment on site, and Noga Ambulance stood by.

The city hall evacuees all stood in the parking lots around the building.

Several firemen had put on hazardous-materials suits, with respiratory and skin protection, to get a sample of the powder and determine its composition.

“Everyone who had been in council chambers during the incident was offered decontamination on site. Most of them went inside and changed into contamination gowns, and we took their clothing and are cleaning it for them because we have the resources to do that,” Kobbe said. “They went home in decontamination gowns and were instructed to shower and wash thoroughly and report any symptoms they have and seek medical care.”

Kobbe said council chambers and the corridors outside of it were professionally cleaned by a company contracted by the city. There was no contamination on the first floor, which was open Wednesday, Kobbe said, but no one was allowed upstairs into council chambers or in the hallways until it was decontaminated.

He added that the mayor’s office and other second floor administrative offices were open Wednesday.

“We were there till 9 p.m. last night to make sure everyone was accounted for and no one had symptoms, and we decontaminated all of our own personnel to make sure no one was exposed,” Kobbe said Wednesday.

NEW CASTLE NEWS reporter Maria Basileo contributed to this report.