Some 240 gallons of sodium cyanide briquettes spilled Thursday morning on I-15 in central Utah, prompting public safety officials to close a nearly 60-mile stretch of the freeway from Scipio to Cove Fort.

The driver of the truck, Charles Simon, 24, of Aurora, Colo., and a Utah Highway Patrol trooper drove to the Millard County Hospital in Fillmore where they were examined for side-effects. Both were treated and released. Two other people exposed at the scene were not injured.Another trucker, Kerry Knighton of Kearns, employed by Transcon, unknowingly drove through the area at the time of the spill, and on arriving at Salt Lake complained of headaches and foul smell.

According to a nursing supervisor at Holy Cross Hospital, he was treated in the hospital's emergency room just after 11 a.m. Thursday, then released. Salt Lake City-County Health Department is doing the decontaminating of the vehicle.

Thursday's accident occurred at about 4:35 a.m. at milepost 141, 20 miles south of Fillmore on I-15.

According to Lt. Scott Duncan, section commander of the Utah Highway Patrol in Cedar City, the tractor-trailer unit lost part of its load when the barrels came lose from the trailer.

Doug Richards, spokesman for Great Western Chemical in Portland, Ore., said the briquettes were being shipped by MidAmerican Lines from South El Monte, Calif.

Duncan identified the truck owner as Simons and Sons of Aurora, Colo. The truck's apparent destination was Green River, Wyo., via Salt Lake City.

According to the driver's report, the top layer of briquettes broke loose on a curve, rupturing 80 of the 180 drums. The toxic chemical, used in electroplating and as an insecticide, spilled along a three-quarter section of the north and southbound lanes. Traffic was diverted onto U.S. 89. Because the highway does not permit triple semitrailers, drivers were being asked to drop part of their load first.

The spill occurred in a rural area and no evacuation was necessary.

Duncan confirmed that the truck was not involved in any type of an accident - other than losing its load.

Sodium cyanide in this solid form can be fatal if absorbed into the skin, inhaled or handled. If water is introduced into the powder, a poisonous gas will be formed.

For this reason, the Utah Department of Health issued a warning to anyone who may have stopped to help the driver - or merely drove through the area - to report to a hospital, doctor or clinic.

"The difficulty is in the potential," said Mark Burrell, special assistant to the director of environmental health. "Should there be precipitation on the briquettes, there would be a reaction creating cyanide gas. If there is any leaking diesel fuel, it would create the same problem."

Burrell said the health department attempted to warn anyone who assisted at the site to get rid of the clothing they were wearing - to put it in a sealed bag. They should also bathe themselves in baking soda and water.

"Our concern is that the individuals who exercised good citizenship managed to get some of the sodium cyanide on their clothing. This has a potential of creating a hazard for their family and themselves," Burrell said.

Responding to the spill was an emergency response team from Jack V. Kelly Co. of Woods Cross.

According to company executive Lee Nixs, five people drove to the spill area to assist in the clean-up. They carried with them "space-like" suits provided by the State Health Department.

Clean-up efforts are expected to continue throughout Friday.