Early last month, the U.S. Chemical Safety Board approved urgent safety recommendations on gas purging. Unfortunately, the action was not enough for six workers who died and dozens of others who went to the hospital three days later on Super Bowl Sunday after a natural gas explosion at a Kleen Energy power plant construction site in Middletown, Conn.

The recommendations grow out of the CSB’s investigation into a natural gas explosion in June at the ConAgra Slim Jim production facility in Garner, NC, which caused four deaths, and sent 67 others to the hospital.

CSB investigators determined that the catastrophic explosion resulted from the accumulation of significant amounts of natural gas that had been purged indoors from a new 120- foot length of pipe during the startup of a new water heater in the plant. During pipe purging, workers feed pressurized gas into a pipe in order to displace air or other gases so that only pure fuel gas remains in the piping when it is connected to an appliance such as a water heater or boiler.

“The board is very concerned that companies across the country continue to purge pipes indoors,” said CSB Chairman John Bresland. “Currently, the codes of the NFPA and ICC do not require gases to be vented outdoors or define adequate ventilation or hazardous conditions, nor do they require the use of combustible-gas detectors during these operations. The CSB recommendations, if adopted, would urge that these things be done.”

The CSB issued a safety bulletin on gas purging in October 2009, because of the occurrence of multiple serious accidents during purging operations.

What’s even more concerning, though, is that reports indicate potentially unsafe practices precipitated the Connecticut explosion on February 7th. The site was later declared a crime scene, and a probe is looking into whether criminal negligence may have led to the explosion. Evidently, in the hours leading up to the explosion, operators pumped enormous quantities of natural gas, in a series of purges, into a man-made depression behind the main plant structure, where just yards away, welding work was taking place.

While the venting was to the outdoors, the last of a series of gas purges was vented into a narrow space between two massive towers, where investigators believe the explosion occurred. The Hartford Courant reports that for most of the morning the smell of natural gas was so pervasive inside the main building of the plant that some workers complained of dizziness. Others walked off the job.

One of the victims was Chris Walters, a member of the American Society of Safety Engineers who was working at the site as a contract safety manager. He was monitoring a gas meter, and may have issued a frantic warning of unsafe gas levels just moments before the explosion.

A resident of Florissant, Mo., Walters was an ASSE member since 1981 and has worked as a safety professional for more than 20 years.

“Chris was a very active member of ASSE, a fellow St. Louis Chapter member, and respected safety professional,” said ASSE President C. Christopher Patton, CSP. “As occupational safety and health professionals, we work every day to make sure that workers, our co-workers, leave work injury and illness free. That’s what Chris had been doing for more than 20 years.”

A Central Missouri State University (CMSU) alumni magazine recently featured the father of three for his work in the construction of the new Busch Stadium in downtown St. Louis, stating, “Hunt Construction credits CMSU graduates Chris Walters, safety manager, and his assistant, Joe Enright, for helping establish one of the best safety programs in the industry.”

The company’s lost-time injury rate building Busch Stadium was 82 percent below the national average, helping the $344 million-plus project stay on schedule and on budget. “We are all deeply saddened by Chris’ death,” Patton said.

“We salute Chris for all he has done the past 20 years as a dedicated safety and health professional. Because of people like him, millions of workers in the U.S. go to work and leave work injury and illness free every day.” Unfortunately, it’s not always an easy or safe thing to do.