Fire officers have contained the leak of hydrochloric acid at a chemical plant at Trafford Park, Manchester, police said.
Superintendent Chris Ullah from Greater Manchester Police said:
Emergency services have been working at the chemical plant at Trafford Park this evening and have isolated the leak.
There are no reports of injuries or any people requiring medical attention.
We are now starting to scale down the emergency service response and return normality to the area as quickly as possible.
The cause of the leak is not yet known but will be investigated once the building is safe.