The setting featured hot sand, an occasional breeze and a pervasive stench.

And no, it wasn’t one of those beaches invaded by pungent foreign seaweed or reeking, blooming algae. It was the cleanup site on Interstate 10 near College Drive in the aftermath of a cargo spill Tuesday morning responsible for increased agitation and frequent rerouting among drivers in the capital city.

In the beginning, the spilled material could not be identified. Even in the end, it remained officially a mystery, as the substance was declared nonhazardous early on in the cleanup process, meaning the goal was simply to clear the road rather than to collect samples for lab testing identification.

But unofficially, the culprit could not escape public humiliation.

“It appeared the spill was some type of roofing tar material,” said Cpl. Don Coppola Jr., a Baton Rouge police spokesman. “It fell off a vehicle that was traveling down the interstate. They may not even have known it fell off.”

The spill happened about 8 a.m. By 10 a.m., the roadway was cleared. But not before many morning commutes had been extended, perhaps allowing a record number or workers to blame their tardiness on roofing tar.

The unluckiest of travelers even picked up physical evidence of the stinky spill.

“People did complain that the stuff got on their cars,” Coppola said.

John Visalli, a roofing contractor at Premier South Roofing and Sheet Metal Contractors in Baton Rouge, said roofing tar — the asphalt-like substance made using material such as the kind spilled Tuesday — is mostly used as an adhesive on commercial buildings with flat roofs. He described the smell it emits as “almost like somebody’s burning something in the kitchen.”

About 50 gallons of the powdery, black material spilled Tuesday onto the interstate. The Baton Rouge Fire Department’s Hazardous Materials Unit arrived but was not needed once the spilled substance was deemed non-hazardous, said Rodney Mallet, a spokesman for the Department of Transportation and Development.

A DOTD cleanup crew eventually spread sand across the affected area, scooped it up and, finally, swept the road.

Roofing tar material spills are not common, Mallet said. He described the substance as sticky, goopy and rancid.

As a result of the spill, vehicle congestion extended Tuesday morning for miles on I-10 eastbound toward Lafayette. Slow-moving vehicles also filled I-110 southbound toward the state capitol for hours.

“Traffic was backed up for quite some time,” Mallett said.

But the interstate was never completely closed, as it was during ice storms this winter or when a truck crashed and began leaking a flammable substance about two years ago.

And, perhaps most important, no one was injured.

Follow Ben Wallace on Twitter @_BenWallace.