Abstract: At 9:30 a.m. on February 22, 2002, Employee #1, a sanitation operator for a cheese manufacturer, removed the guard on a block former, which caused the caustic-soda solution in the block former to splash on him. During the CIP process, water and disinfectants (acid and caustic soda) cleaned inside the blocker. Machine M and N were programmed by the manufacturer to shut off the CIP process if the guard was removed. However, the door on the block former opened and released the solution inside. All other block formers in the employer's production area were programmed not to release the door or to stop CIP, even if the guard was removed during the CIP cycle. The serial number of the block former was 92251. Stoelting, Incorporated manufactured the block formers. At the time of the incident, Employee #1's supervisor was working a few machines away from him. Employee #1 was hospitalized to treat his chemical burn.