Ten firefighters were treated for skin irritations after a chemical fire forced the evacuation of the Henry Eyring Chemistry Building at the University of Utah Wednesday afternoon.

A university staff member was moving plastic containers filled with waste chemicals into the hallway outside a chemical store in Room 4203 before moving them to a hazardous waste disposal truck that was waiting outside. He returned to the room and found one container on fire shortly after 2:30 p.m.Campus and Salt Lake fire officials said the container, which was sitting under a ventilation hood, may have ignited spontaneously and then burned itself out by the time firefighters arrived to find the fourth floor of the building filled with thick smoke.

All of the firefighters who went inside wore gas masks. Some had full-body protective suits.

Salt Lake Battalion Chief Gordon Nicholl said 10 of the firefighters who entered the building before the smoke was cleared complained that their arms were burning and were taken to University Hospital for decontamination.

Chemistry Department Chairman Peter Stang said he dismissed all faculty and staff and canceled all classes and labs in the building for the rest of the day while the building was being ventilated and cleaned up.