Seven West Valley City firefighters were treated Monday at Pioneer Valley Hospital after they were splashed with hydrochloric acid while extinguishing an industrial fire at Johnson Matthey Corp., 4601 W. 21st South.

Deputy Fire Chief John Williams said the firefighters experienced redness and tingling sensations after exposed skin areas were splashed with the acid. Admitting them to the hospital "is completely precautionary and we don't expect any continuing problems," he said. The firefighters were later released from the hospital.Firefighters were called to the scene about 7 a.m. after a Johnson Matthey security guard and an early arriving employee, Vicki Bennett, observed smoke coming from a processing vault, a 20-foot by 20-foot room.

Bennett, the company's technical services manager, said the vault is used as a secure area to chemically process precious metals that are refined at the plant. The processing involves chemically purifying the metals in plastic containers made of polyvinyl chloride, more commonly called PVC.

No employees were exposed to the toxic fumes, Bennett said. "The shift does not begin until 7:30 a.m., so no one was in the building when we discovered the fire."

Bennett, who heads the company's safety program, said officials suspect that an electrical malfunction caused the blaze, which melted several five-gallon containers holding the acid.

Williams said dry chemical extinguishers were used to douse the fire. The firefighters, who were wearing protective equipment, were splashed when water was brought in to help wash down the affected area.

An investigation is expected to begin after the affected area has been decontaminated by company clean-up crews. Williams said West Valley fire crews will decontaminate city equipment and assess whether any was damaged in the fire fighting effort.

"Once the area is secured, we will begin our investigation," Williams said. "That probably won't begin until sometime this afternoon."