"Mass hysteria" reported at a Massachusetts manufacturing plant on Sunday resulted in more than 20 people being hospitalized over the course of the day following an afternoon chlorine leak.
The leak was first reported in the chemical storage room of Thermal Circuits Inc. in Salem about 3:30 p.m. and a hazmat crew responded to the scene, WBZ-TV reported.
The Boston Globe reported the building was evacuated when the hazmat crew arrived and WBZ-TV said the crew indictated the building was safe to re-enter about 8 p.m.
Then multiple ambulances were requested at the plant about 9:30 p.m. and some workers were taken to North Shore Medical Center Salem Hospital, WBZ-TV said. A hospital spokesman said 20 people were being treated there.
Several people at the plant reported difficulty breathing, nausea, and other symptoms, including possible loss of consciousness.
Acting Salem fire chief Gerry Giunta told CBS News on Monday that a total of 29 people were treated, including one who had suffered an apparent seizure and had been transported to a Boston hospital.
The majority of the patients were treated and released but some, including the individual believed to have had a seizure, remained hospitalized.
"There seemed to be a panic in the building," Salem deputy fire chief Alan Dionne told WBZ-TV after reporting that workers began running from the facility.
"They all exited rapidly, which caused a mass hysteria, in my belief . . . a lot of people got very upset and very excited," Dionne told the Boston Globe.
Firefighters said they did not detect any chlorine in the plant when they came back the second time, CBS News said.
Occupational Safety and Health Administration and the Department of Environmental Protection officials were expected to assist in the investigation at the plant, which will remain closed Monday, Dionne said to the Globe.
CBS News described the facility as an e-cigarette plant, but the Thermal Circuits website said the plant manufactures surface heaters, air heaters, molded heaters, heater assemblies, and infrared panel emitters.
© 2026 Newsmax. All rights reserved.