Air meters show no hazards after a chemical plant explosion early Thursday morning in Newburyport that left one person missing.
Acting Newburyport Fire Chief Stephen H. Bradbury III said his department and mutual aid partners remain on scene of what became a seven-alarm hazardous materials incident at PCI Synthesis, 9 Opportunity Way.
Fire officials said there is no danger to the public and environmental cleanup crews are on scene assessing any impact the incident may have caused to local streams. The federal Occupational Safety and Health Administration, U.S. Environmental Protection Agency and Massachusetts Department of Environmental Protection are also investigating.
Five workers were in the building at the time of the 12:45 a.m. explosion. Four were taken to a local hospital, where they were treated and released. A fifth worker remains unaccounted for. Upon arrival, fire crews saw that an industrial-sized vat from inside the building had been ejected about 30 feet to an adjacent parking lot.
Mutual aid was provided by State Fire Marshal Peter Ostroskey and a number of local fire departments including Haverhill, North Andover, Groveland, West Newbury.
The cause of the explosion is under investigation by the Newburyport Fire Department and State Police Fire and Explosion Investigation Unit attached to the State Fire Marshal’s office.