Abstract: At approximately 12:55 on August 18, 2011, Employee #1, with Chevron Energy Technology Co., was working at a geology warehouse facility where core samples would be tested. He was operating a Wilton VS 20 in. drill press (Serial Number 8030471) to cut core plugs from core samples using 0.75 in. to 2.25 in. diameter drill bits with diamond tips (core barrels). To prevent samples from becoming contaminated by a dirty core barrel previously used to core a different type of rock, employees would clean a drill bit before using it on a different core. The established practice for diatomite, a particularly oily and dirty rock that tends to clog the core barrel, was to allow the drill barrel to rotate during cleaning to produce an even core plug. The rotation also prevents the operator from grooving the shaft or damaging the diamond tip by applying too much pressure. Preparation included using a 1.5 in. by 24 in strip of emery cloth and/or a stiff wire brush with a 6 in. handle to remove rust and varying degrees of debris from the drill bit, depending on the core sample's geographic source. Coring speed was reduced to the minimum setting of 200 rpm during the cleaning operation. Employee #1 obtained a strip of sandpaper 1.5 in. by 8.5 in., donned poly-liner nitrile gloves he had purchased from a local vendor, turned the drill press on, and began to clean a core drill. When Employee #1 became distracted by a noise, his glove became caught on the rotating drill bit, causing the amputation of a finger. Coworkers quickly shut down the drill press with an emergency stop button. Employee #1 was hospitalized for treatment, including surgery to reattach the finger. Employee #1 had been trained in the operation and cleaning of the drill press, but deviated from established cleaning procedures by wearing gloves, using a sandpaper strip that was too short, and failing to use an extension tool.