LEWISTON – A fire at a shoe company on Commercial Street forced workers outside Wednesday when smoke poured onto the factory floor.

Fire officials blamed burning shoe scraps in the one-and-a-half story hopper of a dust collection system at Allen Edmonds Shoe Corp. Firefighters pulled the leather shavings from the machine and doused them with water, fire Investigator Paul Ouellette said.

When the fire broke out around 8:30 a.m., a maintenance worker had shut off a ventilation fan causing smoke to blow back onto the factory floor. Each workstation has ductwork overhead that sucks scraps and dust off the work floor and sends it into a central hopper.

Team leaders led employees outside to safety in the company’s driveway. No injuries were reported, said Mike Rancourt, a company spokesman.

When workers opened a door into the collector system, they saw flames, Ouellette said. They used four fire extinguishers on the blaze, but couldn’t put it out, he said. A fire prevention system inside the hopper apparently failed because the level of debris was higher than the canisters of suppression powder, Ouellette said. When the powder was released, it wasn’t able to get to the burning materials, he said.

This is the second time in the past six months the dust collection system has not worked properly, Rancourt said.

“The extinguishers in the collector don’t seem strong enough to actually put out a fire,” Rancourt said. The company is expected to evaluate the effectiveness of that system, Rancourt said.

The fire might have been touched off by sparks from a ground nail or tack at one of the work stations. Or, it might have been caused by an overheated collector, Ouellette said.

“We don’t know the exact cause,” he said.

The company, which makes men’s handsewn leather dress shoes, has 115 employees.