Two men were injured when a propane tank exploded inside Eastern Metal Treating, on Bacon Road in Enfield, as they were fueling a forklift on Tuesday afternoon.
Mark Zarcaro, of Shaker Pines Fire Department, said the injuries are not life-threatening.
Ambulances transported both men from the scene. One man suffered an arm injury, officials said.
The building is full of propane vapors, so authorities are waiting for a contractor to clear the air.