The sulfur appeared to have already solidified by the time the spill was discovered at 6:38 a.m., CHP Officer Peter Van Eckhardt said.
It was not immediately clear how the material got onto the roadway, but crews from Shell, which has a refinery nearby, were helping to clean it up, Van Eckhardt said.
There were no road closures as a result of the purported spill, but as of 11 a.m., CHP officers were still at the scene directing traffic, Van Eckhardt said.