Eight fire engines and 58 firefighters and officers were called to a fire at a recycling plant on Ferry Lane in Rainham.
All of the ducting between a paper shredder and baling machine and part of the mezzanine floor of an industrial unit were damaged by the fire.
Seven people left the property before the arrival of the Brigade. There were no reports of any injuries.
The Brigade was called at 1437 and the fire was under control at 1828. Fire crews from Wennington, Barking, Dagenham and East Ham fire stations attended the incident.
Crews are expected to remain on scene damping down into the evening.
The cause of the fire is under investigation.