Up to four cars were damaged by the force of the flames at the garage in Cradley Heath yesterday afternoon.
Around 20 firefighters were called to Bridge Street Service Station, in Garratts Lane, Old Hill, at around 1.30pm.
Garratts Lane had to be closed between Powke Lane and Wrights Lane due to the severity of the fire.
Heavy smoke has filled the air surrounding the garage at the height of the blaze.
Firefighters from Haden Cross, Oldbury and Brierley Hill were on scene for more than two hours.
Teams wearing breathing apparatus are managed to get close to douse flames at the two storey building.
Propane gas cylinders were removed from the garage as a precaution but they were not caught in the flames.
Firefighters did spray water over the cylinders to avert any further outbreaks of fire.
Crews at the scene said they found asbestos inside the building during the course of the fire.
West Midlands Fire service spokesman Neil Spencer said: "One male casualty was treated for burns to his hand and face."
"Crews had to pull back from one area due to the stability of the building."
The man, who works at the centre, was taken to hospital for further treatment.
Environment Agency officials had been called to the scene concerns of any petrol seeping into the water running after from the scene.
Traffic began to build up in the area due to the road closure but this began to ease by 4pm when the road reopened.
National Express West Midlands had to divert the 4M service via Powke Lane, Cox's Lane, Halesowen Road and Reddall Hill Road due to the fire.
Watch Commander Temple Jones, from Haden Cross fire station, said: "We are not sure of the cause of the fire at the moment.
"Luckily we arrived within five minutes of the call and stopped it from spreading to the neighbouring buildings.
"Three or four cars were being worked on at the time.
"But asbestos is involved which could be a hazard so we are speaking with the owner now to get that sorted."