CSB Votes to Approve Urgent Gas Code
On a 2-1 vote, the U.S. Chemical Safety Board approved urgent safety recommendations on gas purging safety at a Feb. 4 public meeting in Raleigh, following extensive testimony and public comment.
The draft recommendations, which were approved as presented by the staff without amendment, urged the National Fire Protection Association (NFPA), American Gas Association (AGA), and the International Code Council (ICC) to strengthen the national fuel gas code provisions on purging. Board Chairman John Bresland and Member William Wark voted to approve; Board Member William Wright voted to disapprove.
In preliminary findings that were presented at the public meeting, 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 that made Slim Jims, a popular beef-jerky product. 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.
CSB Investigations Supervisor Donald Holmstrom said his team made the recommendations to the board during the course of the ConAgra investigation after discovering gaps in the fuel gas codes. "Purging flammable gases into building interiors is a recipe for disaster," he said. "At ConAgra, we determined the accident would not have happened had the gas been vented safely outdoors through a hose or pipe." Holmstrom noted that since the June 2009 accident, ConAgra has instituted strict policies on purging, requiring it be done to safe outdoor locations.
CSB issued a safety bulletin in October 2009 titled "Dangers of Purging Gas Piping into Buildings." The bulletin's key lesson is: "Purging new or existing gas piping into a building can be highly hazardous due to the possible accumulation of gas … and the associated danger of fire and explosion." It noted that large numbers of workers are at risk, including plumbers, gas installers, maintenance workers, contract supervisors, and industrial facility managers.
For more information, visit www.csb.gov.