MIDDLESEX TWP — Ibis Tek, a manufacturing company at the intersection of Route 8 and Cruikshank Road, dodged a bullet this afternoon when an exterior filtration system caught fire.

Firefighters were called at 2 p.m. to the business, where a 30-foot metal filtration system on the exterior of the building's east side smoked heavily. Middlesex, Penn and Saxonburg volunteer fire companies responded to the call.

Larry McCafferty, vice president of human resources for Ibis Tek, said employees noticed smoke and called 911.

He praised the employees for their quick action in spraying the unit with fire extinguishers until firefighters arrived just a few minutes later.

"We are thankful no one was hurt," McCafferty said. "The fire crews responded and went to work quickly."

Glenn Pfeifer, Middlesex assistant fire chief, said a faulty check valve on the filtration unit that prevents sparks from kicking back into the building could be to blame for the fire.

Ambulance personnel from Quality EMS of Mars handed cold water out to sweating firefighters at a "mist station," where they came to cool off in the 94-degree heat.

No damage estimate was available this afternoon.