The fire — about 11 kilometres east of the Olympic Park — was brought under control by late Sunday. A London Fire Brigade statement said the whole of the 50 metre by 100 metre, single-story recycling centre had burned and that, at one point, a plume of smoke could be seen across the capital.
"We've not seen a fire of this size in London for several years," London Fire Commissioner Ron Dobson said. "It's certainly a dramatic end to the Olympics for the London Fire Brigade."
The statement said more than 200 firefighters drawn from across the city had been sent to fight the fire in Dagenham, an industrial, riverside area at the very edge of the capital.
"I would like to reassure people that we are still able to attend incidents across the capital and the fire cover we're providing at the Olympic venues has not been affected," Dobson said.
In a message later posted to Twitter, the fire service said the Dagenham fire had been contained. "We'll be there during the night damping down," the tweet said. "An Olympic effort by our crews. Enjoy the Closing Ceremony."
The cause of the fire wasn't yet known. No injuries have been reported.
A spokesman said the fire brigade didn't keep detailed logs on the size of one blaze or another, but mainly thought in terms of the personnel and equipment needed to tackle each fire. He said the last comparable fires he could remember included the inferno that broke out at London's Camden Market in 2008 and a blaze that gutted the New Look store on Oxford Street in 2007.
In line with office policy, he spoke on condition of anonymity.