2 Incident Description
2.1 Events Before the Incident
The new dust collection system for the pre-mix room was commissioned for service on the morning of Friday, October 5, 2012, and then operated until the end of the production shift at 3:00 pm EST20. At commissioning, US Ink employees who would operate the system (several black ink production supervisors and one of the day-shift operators) received 15 minutes of operational training and instruction as well as a walkthrough of the Fike explosion suppression and isolation system. Both the dust collection system and the Fike explosion suppression and isolation system were equipped with control panels (containing system status indicator lights), installed on the wall near the pre-mix room (Figure 1). As designed, the dust collection system started automatically when any of the mixing tank motors was energized and automatically shut off (after a specified delay) when all mixers were inactive. However, the dust collection system actually continued to run overnight, even when all the ink mixers were shut off.