An employee was standing on the mezzanine level while cleaning the dryer hopper. He was using a hose and spraying water into a cleaning port at the top of the hopper. There are moving parts inside the hopper, and it has to be cleaned while the parts are moving. The employee climbed down to ground level at the base of the hopper. There was another port at the base of the hopper, which contained a vane valve on a rotating shaft. The employee's left index finger entered this port, amputating his fingertip.