The contents within the lorry started smouldering at about 11.40am today on the A495 in Porth-y-Waen near Oswestry.
It is not thought anyone has been injured in the fire.
Six fire crews including the Environmental Protection Unit and the Rescue Tender were mobilised from Oswestry, Tweedale and Wellington.
An operations officer was also in attendance.
Police have also been on scene.