Andover Hazmat due to Chemical Reaction

ANDOVER, MA - A chemical reaction led to an explosion that prompted a hazmat response to a Frontage Road building Monday.

The cause of the reaction at 23 Frontage Rd. was still unknown as of Monday night. Fire officials said no injuries were reported. Officials were called just before 4:30 p.m., including those from the Occupational Safety and Health Administration were also on the scene.

The Boston Globe reported the situation occurred at Morpho Detection LLC, a security company which makes explosive and drug detection equipment. Fire Chief Michael Mansfield told the Globe a "green vapor cloud" hovered above the building.