By Beth Germano

ACTON (CBS) – It was a call for an explosion with injury at the Haartz manufacturing facility in Acton when firefighters encountered heavy smoke and a seriously injured employee suffering burns on both his hands and back.

The cause of the explosion is now under investigation with OSHA also on scene.

READ MORE: Bryan Purdie Charged In Falmouth Home Invasion, Kidnapping

Firefighters immediately put on protective gear knowing the company that manufactures interior trim and convertible tops for cars works with highly flammable chemicals.

Deputy fire Chief Bob Van Der Hoof says firefighters had one thing on their side. “When companies arrived the fire was almost extinguished,” Van Der Hoof said. “They have an extinguishing system in the building which was a plus for us with considerable smoke damage throughout.”

READ MORE: Federal Regulators Say Weymouth Compressor Site Should Not Have Been Approved

Firefighters on scene of a reported explosion at the Haartz Corporation in Acton. (WBZ-TV)

Five other workers also had to be transported for smoke inhalation as the fire was extensive enough to quickly spread from the first floor to duct work in the second floor. Fire officials say the explosion occurred in an area where materials undergo a coating process with the most seriously injured employee working at a machine in an assembly area.

MORE NEWS: McAvoy's Late Goal Lifts Bruins To 4-3 Win Over Capitals

Highly toxic insulation was also removed by firefighters. In a statement, the company said safety is a top priority.

Beth Germano