The fire burned through the National Surtrex Corp on McLean Boulevard just after 6 a.m.
Flames shot out the windows and quickly engulfed the one-story structure. Two firefighters suffered minor injuries.
Nearby Route 20 was closed for fire department activity. Ramps to nearby Interstate 80 were also closed.
Firefighters had difficulty accessing the building and ran fire lines over nearby freight train tracks, affecting service on New Jersey Transit.
The company is a large distributor of medical and safety disposable apparel.
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