Abstract: On October 17, 2007, Employee #1, and other employees were recovering Halon 1301 from four 350-lb cylinders under pressure of 360 psi. Employee #1 was helping the supervisor removing the empty cylinders by attaching the cylinder to the fork of the truck. Employee #1 was never provided with training on hazardous materials. The supervisor was taking one of the empty cylinders to the trash pile. Employee #1 went over to the cylinder that was attached to the pump and used his box cutter to depress the pressure relief needle of the cylinder. This action caused the hissing noise to go away. Employee #1 then went over to the second free standing cylinder. He depressed the relief pressure needle, which caused a violent release of the pressured gas. The cylinder knocked him over and caused some property damage. Employee #1 sustained multiple injuries, head contusion, and bruised liver. He also fractured his lower right leg and dislocated left shoulder. He was hospitalized.