The US Chemical Safety and Hazard Investigation Board on Sept. 24 approved two final reports on accidents that killed six workers. The reports were critical of AB Specialty Silicones of Waukegan, Illinois, where four workers were killed May 3, 2019, and an Evergreen Packaging paper mill in Canton, North Carolina, where two workers died Sept. 21, 2020.The silicones plant was making a silicon hydride emulsion when a flammable vapor cloud developed and ignited, causing an explosion and fire. In addition to the deaths, a fifth employee was seriously injured. The CSB found that workers inadvertently mixed several incompatible chemical compounds that were stored near each other in nearly identical drums, generating hydrogen gas that ignited.The facility lacked an adequate ventilation system and a working alarm system, the CSB noted.
It was surprising to me that the various chemicals were all in 55-gallon blue drums. They could be easily confused, although there are plenty of ways (different staging sites, double-sign offs, ID verification) that you could stop operators from charging the wrong reagents into reactors.