Five fire crews sped to JGW Coatings on the Barbot Hall Industrial Estate, Mangham Way, Parkgate, to deal with the blaze which started at 12.40pm.
Four engines and one aerial ladder platform attended the fire and the site was cordoned off.
Two crews from Dearne fire station, along with one from Darnall and one from Rotherham tackled the flames, a South Yorkshire Fire Service spokesman said.
Thick black smoke could be seen billowing up into the sky for miles around.
Rotherham Council closed off Mangham Road and Taylors Lane, which runs through the estate, and buses were also diverted causing lengthy traffic delays in the area.
A Rotherham Council spokeswoman said: “A main route through a Rotherham industrial estate will remain closed until further notice because of a fire.
“Mangham Road and Taylors Lane, which runs through the Barbot Hall industrial estate, is closed along its entire length between the Great Eastern Way roundabout and the Carr Hill roundabout.”
Stagecoach bus services 4, 14, 42, 108, 109, 200, 218, 220, 221, 224, 226, 229 and Magic Bus 22 have all been affected and are delayed by around 20 minutes.
PICTURE: MARK OAKLEY