The Kleen Energy plant in Middleton, Connecticut.The Chemical Safety Board (CSB) is praising Connecticut for enacting legislation that will permanently ban the practice of using flammable gases to clean fuel gas piping during power plant construction.

CSB member William Wark called on other states to do the same, citing the gas blow-caused 2010 explosion at the Kleen Energy plant in Middletown, Connecticut which killed six workers and injured dozens of others. The accident occurred at a natural gas electric generation plant which was under construction.

"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,” said Wark. “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.”

The CSB has recommended that OSHA develop a standard on fuel gas safety and has advised states, localities and voluntary consensus standards organizations to amend their codes to prohibit the practice.

The National Fire Protection Association (NFPA) 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.

Wark said an estimated 125 natural gas-fueled power plants are expected 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.”