Abstract: At approximately 1:30 p.m. on May 16, 2003, Employee #1, a contractor, was removing the lockout on a 1968 10-inch cast-iron Stockham FG-G634 valve on one of the main steam lines feeding the cook area of a Del Monte Foods Plant in Modesto, CA. The steam piping for the cook area comes directly from the boiler which is set at approximately 150 psi at 364 degrees Fahrenheit. The main steam line piping and this valve were located between 20 and 30 ft above the floor. Employee #1 was using a 4-ft shock- absorbing lanyard and harness, and was tied off to the valve handle. After removing the lock and turning the valve open approximately three turns, the valve began to shake and then exploded. The explosion initial threw Employee #1 back, but he began swinging in his harness directly into the steam emitting from the main steam line. He was able to get himself out of the harness and fell to the ground. Employee #1 was assisted by Del Monte employees, who brought him to their on-site first-aid center. Emergency responders transported Employee #1 to Modesto Memorial Hospital. He was then transported by helicopter to the UC Davis Burn Center for treatment of second- and third-degree burns to over 60 percent of his body.