Statement by CSB Board Member William Wark Commending the State of Connecticut for Enacting Legislation to Prohibit Flammable Gas Blows at Power Plants

August 26, 2011

                August 26, 2011 -  Today I wish to commend the Governor and General Assembly of the State of Connecticut for enacting legislation that will permanently ban the deadly practice of using flammable gases to clean fuel gas piping during power plant construction.
It was gratifying to witness today’s ceremonial signing of Public Act 11-101 by Governor Dannel P. Malloy in Hartford, Connecticut.  
I am pleased that this quick and effective action was taken following the February 7, 2010, tragedy at Kleen Energy. The CSB’s investigation into the accident found that a series of natural gas blows led to an explosion at the natural gas electric generation plant, which was under construction in Middletown, Connecticut. The accident killed six workers and injured at least 50 others.
The Connecticut legislation sets an example for the rest of the country and the Board has called on all other states to follow suit. The tragedy at Kleen Energy was preventable, and that’s why the CSB earlier made a formal recommendation to the state of Connecticut to ban the practice. The CSB concluded that using gas blows to clean piping is inherently unsafe, and should no longer be permitted in the construction of power plants. Additionally, the Board has made a recommendation to the federal Occupational Safety and Health Administration (OSHA) to develop a standard on fuel gas safety and to the states and localities, and voluntary consensus standards organizations to amend their codes to prohibit this unsafe practice.
I am encouraged by the exemplary actions of the State of Connecticut, and I was also very pleased to learn that the National Fire Protection Association recently approved a new gas process safety standard, NFPA 56, Standard for Fire and Explosion Prevention During Cleaning and Purging of Flammable Gas Piping Systems. This voluntary standard also prohibits the practice of using flammable gas to clean piping.
These actions have the potential to prevent tragedies such as that which occurred at Kleen Energy. And these actions are urgently needed, since the CSB found that 125 or more natural gas fueled power plants are anticipated to come online over the next five years. In many of these instances, new or refitted plants may opt to use gas blows despite the inherent dangers, simply because gas is conveniently available. I thank the State of Connecticut for prohibiting this inherently unsafe practice, and urge other states and localities to follow suit.  
Pipes which supply flammable gas to gas-fired electrical turbine generators must be cleaned of construction and other debris prior to initial operation.  The CSB’s investigation found that on the day of the accident at Kleen Energy, contract workers were cleaning fuel gas piping by forcing large amounts of flammable gas through the pipes. Natural gas was forced out of vents located near ground level, adjacent to the power generation building. Just before 11:30 am, the accumulated gas ignited, triggering a massive explosion.             

       As a result of the Kleen Energy Investigation the CSB issued a total of 18 urgent safety recommendations at a public meeting in Middletown, Connecticut, on June 28, 2010. This included a recommendation that the governor and legislature of Connecticut enact a law prohibiting the use of flammable gas to clean fuel gas piping during power plant construction.  
Recommendations were also made to the Occupational Safety and Health Administration (OSHA) calling for federal regulations that would prohibit the release of flammable gas to the atmosphere for the purpose of cleaning fuel gas piping. The Board also issued similar recommendations to two major voluntary standards organizations - the National Fire Protection Association (NFPA) and the American Society of Mechanical Engineers (ASME) - to amend their respective codes and standards to require the use of inherently safer methods during the cleaning of fuel gas piping.  
 Earlier this year, the CSB released a 15 minute safety video that includes a 3-D animation of the events leading up to the accident at Kleen Energy. Entitled “Deadly Practices,” the video shows the hazards of releasing gas into areas where it can accumulate, ignite, and kill or injure workers or members of the public. The video is available online at and on the CSB’s YouTube channel. 
The CSB is an independent federal agency charged with investigating serious chemical accidents. The agency's board members are appointed by the president and confirmed by the Senate. CSB investigations look into all aspects of chemical accidents, including physical causes such as equipment failure as well as inadequacies in regulations, industry standards, and safety management systems.
The Board does not issue citations or fines but does make safety recommendations to regulatory agencies such as OSHA and EPA, legislatures, corporations,  industry organizations, labor groups, and other institutions that can prevent similar events in the future. Visit our website,
For more information, contact CSB Communications Manager Hillary Cohen (202-446-8094, or Sandy Gilmour, 202-261-7614 or cell 202-251-5496.     
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