Silently after nightfall, an uncontrolled chemical reaction began in a vessel holding thousands of pounds of toxic substances. Gas pressure began to build, opening a safety device designed to protect the vessel from bursting. However, the chemical plant lacked equipment to contain the release, and a cloud of unidentified gases began wafting through nearby neighborhoods.
By the time sleepy residents realized what was happening, many had been exposed. Emergency responders, lacking the proper equipment and experience, alerted residents by going door to door and struggled to help the contaminated and the sick reach the nearest hospital.
These were the actual events of April 12, 2004, in the northwest Georgia community of Dalton. But to those of us who study chemical-process safety, there are eerie similarities to the events of Dec. 3, 1984, in Bhopal, India, where an uncontrolled release of 90,000 pounds of methyl isocyanate gas from a US-owned chemical plant immediately killed several thousand residents - and ultimately thousands more - and shocked the world.
Fortunately, the gas release in Dalton was smaller and less toxic, the area around the plant was less densely settled than Bhopal, and a fortuitous rainstorm helped suppress the hazardous fumes. While 154 Dalton residents were sent to the hospital for evaluation, none died.
Nevertheless, the incident illustrates that 20 years after the Bhopal tragedy, inattention to chemical safety can still threaten the public with a devastating impact.
Are we doing enough to prevent such accidents? I have been thinking about this question a great deal since returning recently from a conference in Kanpur, India, to examine the causes and consequences of Bhopal on the 20th anniversary of the accident. The agency I head, the US Chemical Safety and Hazard Investigation Board (CSB), is one of Bhopal's many legacies, established by Congress to independently investigate significant chemical accidents, determine root causes, and make recommendations to prevent future accidents.
Our investigations of major accidents provide persuasive evidence that serious safety problems still exist among some US operations that store, use, or produce chemicals. The problems often occur at smaller businesses that may lack substantial safety expertise or receive less frequent oversight from regulators. A striking example was the chemical explosion at a small signmaking company in Manhattan two years ago, which injured 36. Elsewhere, we have seen employers using untrained workers to handle highly hazardous materials, workplaces where critical safety equipment is absent or in disrepair, and emergency-response plans that leave nearby residents confused about what to do.
There have been significant regulatory changes and other improvements in the past 20 years, and both industry and government continue to look at chemical safety issues in light of the Sept. 11 attacks. Among new federal rules are chemical process safety regulations adopted by the Occupational Safety and Health Administration in 1992 and the Environmental Protection Agency in 1996. Industry has developed its own voluntary standards as well, such as the American Chemistry Council's Responsible Care program, which commits members to environmental and safety principles and community outreach. These efforts have had positive effects.
But substantial challenges remain. Not all companies join voluntary programs, and not all voluntary programs result in verifiable improvements. In addition, federal process-safety regulations still do not address the cause of many chemical accidents. Prompted by tragedies in Lodi and Paterson, N.J., in the 1990s, the CSB conducted a study of 167 serious accidents in the US involving uncontrolled reactions since 1980. The study found that more than half of these accidents involved chemicals not covered by process-safety regulations, and we therefore recommended broadening those rules.
Around the country, accidents continue to kill or injure workers, impact communities, and in some cases have the potential for wider destruction. Last April, at a plastics production plant in central Illinois, five workers were killed and others were seriously injured when flammable vinyl chloride leaked, ignited, and exploded near a production unit. An emergency system designed to suppress the vinyl chloride vapor cloud malfunctioned.
At a chlorine repackaging plant near St. Louis two years ago, a transfer hose burst and none of the plant's four automated emergency shutoff valves closed. The result was a 48,000-pound chlorine gas release, which imperiled a mobile home community. As in Dalton, Ga., neither the community nor the plant had emergency sirens or automated telephone alert systems, and firefighters had to go door to door to alert residents to evacuate.
Indeed, a common finding is that plants and local emergency response organizations often lack any effective means to notify nearby communities about major chemical accidents. Furthermore, despite increased funding for homeland security, some jurisdictions remain unable to provide firefighters and police with the training and equipment needed to respond to a toxic chemical emergency.
Sometimes it has been good fortune rather than sound planning that has prevented chemical accidents from jeopardizing lives. At a south Mississippi petrochemical complex two years ago, a massive explosion blew apart a 145-foot distillation tower, hurling heavy debris into the air and igniting fires. When CSB investigators reached the site, they found that metal debris had missed an anhydrous ammonia storage vessel by just a few feet.
Most US chemical plants are run in a safe and conscientious manner. But until all companies live up to the same high standards, we will continue to experience major chemical accidents. It is up to all firms that use and produce chemicals to eliminate known hazards, to develop and maintain a positive safety culture, and to educate customers about accident risks.
As a result of the Bhopal accident, thousands died and tens of thousands more were injured. That nightmare could have been avoided the same way accidents today can be avoided: through meticulous commitment to safety at every step of the process. Twenty years after Bhopal, we owe those victims - and our own workers and communities - no less.
• Carolyn W. Merritt is chairman and CEO of the US Chemical Safety and Hazard Investigation Board, an independent federal agency in Washington.