THE A419 London Road is closed both ways due to a spillage of acid and building fire at The Eagle Works Site between Brimscombe Lane and Spring Lane.
Following the fire last night, the road remains closed with emergency services remaining on scene.
Affecting traffic between Stroud and Cirencester.
Motorists are being asked to avoid the area and to keep doors and windows closed.
Police said at 9.53am that London Road would remain closed until further notice while fire crews dampen hotspots.
Speaking this morning at 6am, a Gloucestershire County Council spokesman said: "The fire is now out. Two fire engines remain at the scene as a precaution.
"The A419 at the junction with London Road is still closed. Advice to local residents is to stay indoors, close windows and listen to media updates."