An employee was using a pressure washer with a pressure rated at 3,000 psi. The pressure washer had a 5’ 2” wand attached to it. The injured was washing the sack room walls and climbed up a fixed ladder that was attached to the bulkhead and started to clean the wall from the top down. He was standing on the ladder and leaning back against the barite hopper tank, which is about 3’ 6” from the wall. At some point he turn the wand down and started cleaning the wall downward. As he was cleaning he ran the pressure washer across the top of his rubber boots, resulting in an injection injury to his left foot.