Abstract: At approximately 2:30 p.m. on January 19, 2010, Employee #1 was running a Muller Martini Prima Saddle Stitcher and 3-Knife Trimmer in the Bindery Department of a full-service printing company. According to Employee #1, scrap had started to build up at the head knife, so he reached into the machine to brush it away. Employee #1 contacted the knife, which cut several of his fingers. Employee #1 stated the trimmer had air nozzles which usually blew the trim into an evacuation system, but on this run the material was either too thin or had too much static, or the nozzles were not adjusted properly, which caused the backup. The Trimmer did have a total hood guard protecting the head knives. At the time of the accident, the interlock system and the Plexiglas window on the door of the guard were broken, which allowed Employee #1 access into the machine while it was running. Employee #1 could not recall if the door was open or if he just reached through the hole in the Plexiglas. The plant manager believed that the door was open and the hood pushed open when he arrived on scene just moments after the accident occurred, which indicated that Employee #1 contacted the moving head knife through the open door and pushed the hood back upon pulling his arm out of the machine after the accident.