A number of streets were closed in the area as firefighters tried to put out the fire.
An apartment building across the street from the old factory was evacuated because of elevated carbon monoxide levels. There are 52 units in the building.
Authorities were worried about prolonged exposure to the CO levels because this fire was expected to burn for hours.
Police evacuated a couple dozen people to a nearby shelter. Officials said some were refusing to leave, while others left on their own.
Police also advised residents in the area that they may have low water pressure and/or brown water due to the fire department activity.
The factory was empty, so officials said there were no dangerous chemicals inside.
The Bergen County Health Department was on scene taking air samples, but did not find anything toxic.
The building once housed Interplast Universal Industries.
NEW YORK AND TRI-STATE AREA NEWS