"Our main concern is that the stacks don't fall on any firefighters," Mayor Robert Colletti told Daily Voice. "It's a building filled with a lot of paper."
Heavy smoke made it difficult for crews to initially locate the blaze, which began at the Market Street factory around 5 p.m.
Soon after, they found it embedded in a paper storage area.
Flames headed toward the roof as smoke poured out the windows, they said.
But 100 or so firefighters from nearly 20 departments helped keep things from getting worse.
Forklifts were being used to move whatever combustible materials that could be reached from the area.
Saddle Brook and Garfield firefighters were among the first to join their colleagues.
Lodi and Paramus crews provided mutual aid for the borough. Hawthorne was summoned, as well. Others responding included Fair Lawn, Clifton and Paterson.
No serious injuries were immediately reported.
"I am just praying all our brave men and women come through safe," Councilman Joseph Dombrowski said.
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