Accident: Emergency Shutdown Systems for Chlorine Transfer
Location: Location: ,
Accident Occurred On: 08/14/2002 | Final Report Released On: 06/14/2007
Accident Type: Release
Investigation Status: The CSB issued this safety bulletin on June 14, 2007.
This bulletin compares two chlorine releases investigated by the CSB. In both, a railcar unloading hose
failed and chlorine was released. In the first incident, an emergency shutdown system malfunctioned,
resulting in a release of 48,000 pounds of chlorine and a significant community impact. In the second, the
emergency shutdown system worked to minimize the release, and the community was not impacted.
Expand the scope of DOT regulatory coverage to include chlorine railcar unloading operations. Ensure the regulations specifically require remotely operated emergency isolation devices that will quickly isolate a leak in any of the flexible hoses (or piping components) used to unload a chlorine railcar. The shutdown system must be capable of stopping a chlorine release from both the railcar and the facility chlorine receiving equipment. Require the emergency isolation system be periodically maintained and operationally tested to ensure it will function in the event of an unloading system chlorine leak.