Four fire engines and 21 firefighters and officers were called to a fire at a recycling plant in Perry Road, Dagenham last night.
The blaze broke out in a metal container used to store shredded foam before it is removed from the site.
Approximately 75 tonnes of foam was in the container at the time of the fire and the contents were completely destroyed.
An employee at an adjacent company saw smoke and fire coming from the container and called 999.
The Brigade was called at 2226 and the fire was under control at 0150. Fire crews from Barking and Dagenham fire stations attended the scene.
The cause of the fire is believed to be accidental.