Fire razes factory, causes traffic chaos

A fast-moving fire has completely gutted a Sydney furniture factory and caused significant delays for airport commuters.

More than 100 firefighters descended on the Mascot blaze after it took hold of the building about 11.30am on Tuesday.

The Robey St blaze tore through the complex and sent flames shooting metres into the air, but did not spread to neighbouring businesses.

Flash fires continued to flare inside the factory complex after 2pm, with windows and walls destroyed and thick smoke billowing from the blackened factory floors.

Fire and Rescue NSW Superintendent Tom Cooper said there were unconfirmed reports the blaze was triggered when somebody left a toaster on inside the complex.

Supt Cooper said there was no reason to believe the fire was suspicious, but said the cause would be investigated.

He quashed earlier speculation that one or more people may have been trapped inside the burning factory, saying the information proved unreliable.

Fighting the burning factory was proving an arduous task, Supt Cooper said.

"The whole place is choc-full of furniture, full of foam, there's all sorts of metal-framed furniture with spongy seats," he said.

"There's plastics and timber and all sorts in there, the place is just totalled."

Dozens on firies remained on site, dousing the destroyed complex with foam.

Anyone travelling to the airport - particularly the domestic terminals - has been advised to allow plenty of extra travel time amid extremely heavily traffic caused by road closures.