They are currently responding to an incident at a property in Birdham Road, Chichester.
A spokesman said six fire engines were sent to the scene, but it has now been upgraded to ten.
West Sussex Fire added: “Please avoid the area if possible and if you live nearby, remember to keep windows and doors closed.”
The fire has also caused the A286 to be closed between Birdham and Chichester.
More as we get it.