Factory fire may have begun in spray booth

A fire that engulfed a western Sydney factory may have started in a spray painting booth.

More than 30 firefighters fought the blaze, which broke out about 5am on Thursday at a kitchen manufacturers warehouse in Smithfield.

While the cause of the fire is still unknown, a Fire & Rescue NSW spokesman said they'll be investigating whether it started in a spray booth, where items are professionally spray-painted,

Firefighters spent about an hour extinguishing the blaze and remain on scene.