Firefighters have spent the morning battling a dangerous fire at a fertiliser factory in Kwinana.
Department of Fire and Emergency Services were called to the CSBP factory on Kwinana Beach Road around 9.40am on Monday.
22 fire trucks were on the scene battling the large fire.
Police said the fire is now contained, but it will take several hours to completely extinguish.
DFES issued an alert at 10.38am warning people in the area that potentially dangerous smoke is blowing in a westerly direction toward the coast.
People in the area are advised to stay inside out of the smoke and fumes with windows closed.
The cause of the fire is not yet known.