The A272 was earlier closed in both directions after 2,000 litres of sewage fell from a lorry in Billingshurst, according to West Sussex Fire and Rescue Service.
Fire crews were called to the scene between Crimbourne Lane and Sandgates Farm, Billingshurst, at 5.16pm.
A fire spokesman said: “We sent two crews to the scene, one from Billingshurst and one from Horsham.
“There were reports of a fire and upon arrival, up to 2,000 litres of sewage had been spilt onto the road.
“The sewage has been collected and removed and the situation was handed over to Sussex Police.
“Crews used two breathing apparatus, one jet and one high pressure hose reel to deal with the fire.”
Police were called to assist the fire service at 5.27pm and remain on scene.
A police spokesman said: “The fire is now out and police were called to assist the fire service.
“Officers controlled the traffic and closed part of the road.”
Slow traffic was reported in the surrounding areas.