Abstract: At approximately 8:00 a.m. on August 22, 1991, Employee #1, of Sabastasso Foods, Inc., removed the side cover of the machine to pick up some dough balls that had fallen from the trays to the floor inside the machine. She picked up one dough ball that had grease on it. She was trying to wipe off the grease with her right hand when her thumb became caught in the nip point of the sprocket and chain drive. The tip of her thumb, including the bone, was amputated. She was taken to Fountain Valley Hospital for treatment and released after 7 hours. The cause of the accident was failure to de-energize the machine prior to removing the side cover and picking up the dough balls. To prevent a recurrence of the accident, the employer installed a sprocket and chain nip point guard in addition to the cover, and instructed all employees not to remove any guards while the machine is running. The employer already had lockout/block out procedures for maintenance and supervisory employees.