South Wales Police say the recycling plant that was on fire yesterday evening is expected to burn for two days.
Firefighters were called to a blaze at the 'SitServ Recycling Centre' in Llandow Trading Estate in Cowbridge last night.
The cause of the fire is yet to be established.
It's thought that the building has asbestos on the roof. As a precautionary measure, residents within a two mile radius, particularly those in Llantwit Major and Southerndown, are being asked to keep their doors and windows closed.
Premises near to the scene of the fire are also likely to be affected.