A minor chemical spill on the Mercur Canyon road east of U-73 closed the access road to the Barrick-Mercur Mines for about 11/2 hours Friday.

Tooele Sheriff's Sgt. Harry Shinton said the spill occurred when a valve opened on a tanker truck belonging to Matlack Inc., North Salt Lake, allowing liquid nitric acid to spill along a mile of the road.Authorities closed the road to test the spilled chemical and determine the danger.

Shinton said a test at the scene indicated the 52 percent nitric acid solution posed no health threat and crews proceeded with cleanup efforts. Nitric acid can be fatal in doses containing 100 parts per million.

Frank Wicks, president of Barrick-Mercur Mines, destination of the truck, said a hazardous-materials crew from the company responded to the scene and handled the cleanup. He said soda ashes and water were mixed with the chemical to neutralize it. The chemical remained on the blacktop and caused no contamination to the area environment.

"We were fortunate," Wicks said.

Nitric acid is used in gold recovery operations at the mine, and the facility receives weekly shipments. Wicks said the road is used mostly by mine employees and vendors visiting the mine.

Shinton said the accident is under investigation and discussions will be held with the state before a determination is made concerning citations. He said the mine has no responsibility in the incident because the chemical had not yet been delivered.