Abstract: At approximately 7:15 p.m. on August 23, 1990, Employee #1, age 19, was asked by the senior clerk of the department to clean the tortilleria machine. She did not have experience in the cleaning procedure, although she had observed it being done. A tortilleria is an oven-type machine with a conveyor bed running in a clockwise direction that delivers the cooked tortillas. The machine is approximately 8 ft long and 3 ft wide, with all controls in front. It is cleaned using a steel brush with a handle on top, similar to a shoeshine brush. The cleaning operation requires that brushing be done on top of the conveyor bed while the conveyor is running and the oven is off. A hinged cover guard at the rear end of machine has to be lifted to clean it. Employee #1 was cleaning the running end of the conveyor bed with the steel brush when her hand became caught against the machine end frame. The conveyor pulled it farther down until her upper arm became caught and she was injured.