Board Reports On Chlorine Accident

An inadequate safety system led to the release of toxic chlorine gas, the evacuation of a 1.5-sq-mile area, and the medical treatment of five residents and 11 police officers in Glendale, Ariz., in 2003, the Chemical Safety & Hazard Investigation Board (CSB) concluded in a final report released last week. The accident occurred at DPC Enterprises, which repackages chlorine from railcars into smaller containers for local industrial uses. The firm captures chlorine vented from these operations in caustic scrubbers, and it uses the captured chlorine to produce household bleach as a by-product. On the day of the accident, however, excess chlorine was vented to the scrubber, thereby completely depleting the active scrubbing material-caustic soda-and leading to the release of nearly a ton of chlorine during a six-hour period, CSB says. It was the second accidental chlorine release at a DPC facility, the board notes. In 2002, DPC's plant in Missouri released 48,000 lb of chlorine and was also investigated by CSB. The board made some 14 safety recommendations, including several addressing company practices and safeguards, as well as some affecting preparedness of fire and police departments in responding to hazmat accidents and safety publications prepared by the Chlorine Institute. More information is available online at csb.gov.