Firefighters from several towns responded to a chemical fire at 85 Westbrook Road in Essex on Monday.
The fire at Nalas Engineering was reported around 1:30 p.m., fire officials.
The fire was contained to the building and firefighters were allowing the blaze to burn itself out, according to Essex Asst. Fire Chief Aron Schumacher.
Hazmat teams from Guilford as well as the sub base were brought in. Officials from the state Department of Energy and Environmental Protection said they also have a hazmat team responding.
Westbrook Road was closed between 153 Plains Road and Main Street but has since been reopened.
The cause of the fire is not yet known.