Emergency services were called to the Star Combo Pharma facility at Smithfield at 2pm after reports of large volumes of smoke seeping from the building.
Firefighters and a major incident management team were still on the scene tonight as the fire smouldered.
Nobody was inside when it took hold but residents in nearby Greystanes were warned to stay indoors and avoid the area due to smoke inhalation fears.
Local road closures were put in place.
The company makes pharmaceuticals, cosmetics, vitamins and nutritional supplements — shipping across the country and the world.
It’s believed to have just completed a multimillion-dollar upgrade of the factory to meet global demand.
