An ammonia leak on an industrial estate has led to the evacuation of nearby homes.
West Midlands Fire Service was called at 18:00 BST to Beta Heat Treatment Ltd in Summerton Road, Oldbury, where it said approximately half-a-tonne of ammonia is believed to be leaking.
Homes and businesses in a 100m (328ft) radius are being evacuated.
West Midlands Police urged people to keep away and paramedics are also at the scene.
The fire service said six workers had already got themselves out of the site as crews arrived. They have not been seriously injured.
A spokesman added that a “damaged valve” is believed to have caused the leak at site, which uses ammonia to harden steel.
The ambulance service is standing by and the fire service’s hazardous substance unit is also in attendance.
On Twitter, one man said he had been evacuated along with his toddler.