Abstract: At about 10:50 a.m. on September 12, 1991, Employee #1, and an employee of Calpi, Inc., were hydro-blasting a heat exchanger at the Kern Oil & Refining Company refinery in Bakersfield, CA. Earlier that same day, both employees had been required to attend a tailgate safety meeting at which they were trained in using the model 65GYD-216A high pressure water jet cleaning system (hydro-blaster). They were issued proper personal protective clothing in the form of rain clothing and steel toe rubber boots with metatarsal guards. While cleaning the heat exchanger, Employee #1 decided that he needed to look at the section of the heat exchanger that he was hydro-blasting. Instead of communicating with the other employee, and shutting off the blasting nozzle, he lowered the nozzle so that he could see the heat exchanger. As Employee #1 looked down, he continued to lower the nozzle until the high pressure water struck his right foot, cutting through the boot and causing a serious injury, for which he was hospitalized.