There is a chemical spill in Kwinana Beach near Ocean Street.
The spill was reported at about 7am.
The Department of Fire and Emergency Services warned people in an area, bounded by Mandurah Road, Patterson Road, Office Road and Beach Street, they might be impacted by fumes.
Emergency services have evacuated workers at businesses in the area.
Fire and Rescue Service crews are at the scene. They are using detection equipment and remote cameras to observe and monitor the chemical spill.
The chemical is generally used as a fertilizer and side effects of exposure may include stinging eyes and throat.
The Department of Mines and Petroleum, the Department of Environment Regulation, Police and St Johns Ambulance crews are also on the scene.
Ocean Road was closed and other roads may also be closed. Motorists should avoid the area.
Visit www.dfes.wa.gov.au, call 13 DFES (13 3337), follow DFES on Twitter @dfes_wa.
What people should do:
People in the area should remain inside, out of the smoke or fumes, with doors and windows closed as a precautionary measure. Air conditioners should also be switched off.
Stay away from the area. If you are already in the area take advice from emergency services personnel.
People with medical concerns should contact their local doctor or call Health Direct on 1800 022 222.