Emergency services are currently responding to reports of a suspected unknown substance found at Sydney airport.
It is understood that the substance was found close to a passenger jet, with seven fire crews on the tarmac.
Emergency crews arrived at the scene at 8am, with the incident happening near an American Airlines plane.
Fire and Rescue crews were at the hold of the plane, testing the powdered chemical substance which was spilt.
It was determined to be low irritant.
Another sample will be taken before the site is cleaned up and handed back to airport security.