US safety panel seeks tighter chlorine regulation

14 June 2007 20:58  [Source: ICIS news]

WASHINGTON (ICIS news)--Increased federal regulation of chlorine tank car transfer systems is needed to prevent potentially catastrophic spills that could pose a major threat to population centres, US chemical safety officials said on Thursday.

 

The US Chemical Safety Board (CSB) said it has issued a safety bulletin warning that some chlorine railcar transfer systems lack effective detection and emergency shutdown devices to stop high-volume chlorine spills.

 

These shortcomings in chlorine handling systems “leave the public vulnerable to potential large-scale toxic releases”, the board said.

 

The chemical safety agency said its investigators examined an August 2002 chlorine railcar leak incident at Festus, Missouri, in which 22 tonnes of chlorine were accidentally released into the atmosphere.

 

The agency said in that accident, at a DPC Enterprises unloading facility, emergency shutdown valves at the site did not close as designed due to poor maintenance, and the facility did not have a remote shutdown mechanism.

 

“The only way to stop the release of chlorine from the railcar was to send emergency responders through a four-foot deep yellowish-green fog of chlorine vapour to manually close shutdown valves located on top of the railcar,” said the safety board.

 

The CSB said it is sending a formal recommendation to the US Department of Transportation (DOT), urging that the department “expand its regulatory coverage to require facilities that unload chlorine railcars to install remotely operated emergency isolation devices to quickly shut down the flow of chlorine in the event of a hose rupture or other failure in the unloading equipment”.

 

The board said that emergency stop valves built into chlorine rail tank cars are meant to halt leaks if the tanker’s external valve is broken off during transit, but they are not designed to stop leaks during railcar unloading and should not be relied on for that purpose.

 

In the August 2002 incident, hundreds of Festus residents were ordered to shelter in place, and 63 of them later sought medical treatment, including three who were admitted to hospital.

 

The Department of Transportation was not immediately available for comment.  The Chemical Safety Board does not have authority to order further regulation by the department.

By: Joe Kamalick
+1 713 525 2653

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