Ee was cleaning Geho strainers. After isolation, the strainer housing did not fully depressurize. Ee used a wrench to poke through a layer of mud at the top of the housing, causing the housing to depressurize rapidly, releasing hot slurry that struck the ee on the left side of ee's face, and ee's left wrist. Seen at clinic, diagnosed with 2nd degree burns and released to full duty.