Abstract: Employee #1 was operating one of eight hot caustic extraction cells in the bleach plant area of a pulp manufacturer. He had filled the extraction cell with wood pulp stock and had, to his knowledge, secured the cell door using a steel pole lever to tighten the mechanism into place. Steam pressure was then applied at 8 pounds of pressure and the temperature was brought up to 210 degrees Fahrenheit. Within a few minutes, the steam pressure was bled off and then re-applied at 25 psi, bringing the temperature up to 240 degrees Fahrenheit. After a total time lapse of approximately 20 minutes, the cell door opened and spewed hot caustic stock and filtrate into the surrounding area and onto Employee #1. He was burned on more than 60 percent of his body by the deluge of hot caustic stock. It was concluded that the cell door had not been securely and positively locked into place, allowing it to vibrate loose. Employee #1 died as a result of his injuries.