May 1, 2003
CSB Board Votes 5-0 to Approve Report on DPC Chlorine Release, Calls for Industry-Wide System for Hose Identification
(Festus, MO - May 1, 2003) Saying that better equipment maintenance and quality assurance programs could have prevented last year's atmospheric release of chlorine from DPC Enterprises in Festus, the U.S. Chemical Safety Board today approved its final report and recommendations on the accident and called for industry-wide measures to improve chlorine safety.
Meeting before a public audience that included residents, emergency responders, and company officials, the Board accepted the draft investigative report of its staff and also issued a new recommendation that state agencies convene a review of the health and environmental concerns voiced today by residents. About 100 community members and others attended this morning's meeting in Festus. The final report of the Board will be available later in May from the agency's web site, www.csb.gov.
The August 14, 2002, release of 48,000 pounds of chlorine from DPC Enterprises caused 63 people from the surrounding community to seek medical evaluation. Some residents at today's meeting offered harrowing accounts of the event and said they had experienced various lingering effects from the accident. The DPC facility repackages bulk dry liquid chlorine from tank cars into containers for industrial and municipal use in the St. Louis area. Spilled liquid chlorine vaporizes readily to form a toxic and corrosive gas.
The CSB report says that DPC installed an unsuitable hose connecting a chlorine rail tanker to equipment at its Festus facility. The hose braiding was made from stainless steel instead of the recommended alloy, Hastelloy C, which looks identical but is resistant to chlorine. While investigators found that a supplier had furnished DPC with an improper hose, they said one cause of the accident was DPC's lack of effective management systems to prevent such a hose from being placed in service.
The Board called on both DPC and its hose supplier, Branham Corporation, to improve quality assurance programs, e.g. through the use of analyses to confirm that hoses are made from the correct materials. The Board also voted to recommend that chlorine and hose manufacturing companies develop an industry-wide system for positive identification of hoses.
Another root cause cited by the Board was the lack of an effective testing and inspection program for the chlorine emergency shutdown system at DPC. Emergency shutdown valves failed to close properly once the chlorine leak had begun, greatly extending the duration and severity of the release. Investigators concluded that the valves were inoperable due to internal system corrosion, in turn caused by inadvertent introduction of moisture into the chlorine system. DPC's testing and inspection program was inadequate to uncover the faulty condition of the valves before the accident occurred and should be improved, the Board said.
The Board also recommended improvements to emergency response and community notification systems, while Board members praised the efforts of the mainly volunteer forces that responded to the accident. The report found a lack of adequate planning and training for a major release and noted that emergency breathing equipment stored at the plant became inaccessible once the leak had begun. Ultimately it took three hours for personnel in protective suits to reach the rail car and close manual valves cutting off the flow of chlorine, by which time more than half the contents of the tanker had been released.
"Materials verification, emergency shutdown, emergency response: none of these systems worked well enough to protect workers and the public," according to CSB Chairman Carolyn Merritt. Merritt expressed sympathy for the community concerns raised at the meeting and said "local agencies need to be responsive." Merritt earlier authored a successful amendment to the report calling for a follow-up community meeting to be organized by state agencies.
The CSB is an independent federal agency established in 1998 with the mission to protect workers, the public, and the environment by investigating and preventing chemical accidents. The CSB determines the root causes of these accidents and makes safety recommendations to government agencies, companies, and other organizations. The CSB does not issue fines or citations or apportion responsibility for accidents.
For further information, contact Daniel Horowitz, CSB office 202-261-7613 or cell, 202-345-4960.