A faulty shutoff valve in a heating unit is being blamed for a Monday fire at Johnson Matthey Corp., 4601 W. 21st South.

Seven firefighters were sprayed with hydrochloric acid while fighting the fire and were taken to Pioneer Valley Hospital for observation after extinguishing the 7 a.m. fire. The firefighters complained of tingling sensations and skin redness and were released from the hospital after being treated in the emergency room.