Abstract: At approximately 6:00 a.m. on May 2, 2013, Employee #1, a 67-year-old male electrical and instrumentation technician with C P Kelco was working at a site on East Harbor Drive in San Diego. Employee #1 wanted to reset a control valve for an unrelated process downstream from vessel D-16, a fermenter. Employee #1 knew that the steam is released periodically from the vessel in a process called a "blow down." Employee #1 needed to access the valve, which was adjacent to vessel D-16. Employee #1 did not know this, but Vessel D-16 had been undergoing steam sterilization for three-hours and was about to be emptied. The resetting of the valve would only take a few minutes. Employee #1 did not check in with the Vessel D-16 operator. After following his standard procedure and ensuring that no one was in the immediate area, then hanging caution signs and chains, the Vessel D-16 operator went up the stairway to activate the remotely controlled steam blow down valve. While a coworker was walking upstairs, Employee #1 entered the area and began his work with the other control valve. He said he saw coworker upstairs, but did not talk to him. The coworker said that he did not see Employee #1 in the area. The employer had installed a 6 ft tall cylindrical sheet metal curtain or "muffler" around the steam blow down outlet to protect workers. This curtain was open at the bottom at a level about 6 in. above the floor, thus allowing steam to exit at floor level. When the coworker opened the blow down valve, steam exited the vessel and billowed out at floor level around the metal curtain or "muffler". Employee #1 could not see, but he crawled under a waist high horizontal pipe, next to the muffler. His pant legs were open and when crawling, his legs were in contact with the hot, wet floor. The fronts of his lower legs were burned by the steam. Employee #1 washed off with a nearby hose, reported his injury and was taken by ambulance to the UCSD Medical Center where he was treated for second degree burns to both shins and was hospitalized for two-weeks. CP Kelco was a manufacturer of food additives.