A Sydney furniture factory has been destroyed by a massive fire which forced the evacuation of more than 200 people from surrounding buildings.

Firefighters battled the blaze that engulfed the Cootes furniture warehouse at Yenora in Sydney's west, creating a large plume of black smoke that is visible from the city.

Spot fires may flare up under rubble overnight and it's still too dangerous to enter the building and investigate the cause of the blaze, Fire and Rescue NSW Superintendent Ian Krimmer said.