Safety Officials Urge Chlorine Gas Transport Measures

Safety officials are warning about the risk of a potentially deadly release of chlorine gas unless the government requires equipment for transporting it.

A safety bulletin from the U.S. Chemical Safety and Hazard Investigation Board recommends that sites where rail cars unload chlorine have automatic shut-off valves and other devices that can stop the flow of gas in an emergency.

A board survey found that 30 percent of water treatment plants lack the most effective equipment to detect and stop chlorine leaks. That leaves the public vulnerable to large-scale releases.

“Chlorine is a very useful, but highly toxic substance that needs appropriate safeguards to prevent releases and protect the public,” safety board member John Bresland said.

The Transportation Department regulates the movement of hazardous material by rail. But its oversight ends once the material begins to be unloaded at a fixed site. Safety board officials are now recommending that the agency expand its coverage and require companies to install newer emergency shut-off systems.

Ted Willke, the department’s acting associate administrator for hazardous materials safety, said the agency would consider the recommendation.

“We’re in the process of analyzing the data on all serious incidents on unloading and loading of bulk cargo involving hazardous materials,” Willke said. “We’ve found out that it is a serious problem.”

Willke said about one-quarter of “serious incidents” in transporting hazardous substances — such as those leading to death, injury or evacuation — occur during the loading or unloading process.

About 15 million tons of chlorine are produced each year and 3 million tons are shipped by rail. Many water treatment plants that receive the chlorine are in residential communities.

Chlorine rail cars currently have excess flow valves designed to stop the flow of chlorine if a valve breaks off while the rail car is in transit. But those valves are not designed to stop leaks during rail car unloading.

One of the worst chlorine accidents in recent years occurred in 2002 in Festus, Mo., when a chlorine rail car transfer hose ruptured and the emergency shutdown system malfunctioned. About 48,000 pounds of chlorine were released during a three-hour period in the community 30 miles south of St. Louis.

The safety board said the Missouri incident is an example of how the newer safety equipment could have prevented a large release of chlorine.

Art Dungan, president of the Chlorine Institute, said the industry supports the recommendation and wants the Transportation Department to establish uniform safety regulations.

“It’s our intent to promote this bulletin very actively to our members,” Dungan said.

Fred Millar, a chemical safety expert at Friends of the Earth, a national environmental group, praised the safety board’s recommendation.

“No individual company has the incentive to spend money on safety equipment and measures if their competitors are not being forced to do the same thing,” Millar said. “I think they’ve done great work in highlighting the need to have what is an absolutely necessary safety device.”