In a new safety bulletin, the U.S. Chemical Safety Board (CSB) is urging companies, gas installers, and contractors to follow safe practices during gas purging operations. The recommendations were based on the ConAgra Foods natural gas explosion in Gardner, North Carolina.

The explosion, which occurred at the SlimJim meat-processing plant on June 9, 2009, killed three workers when a large section of the building collapsed. The blast critically burned 4 others and sent a total of 71 people to the hospital. About 18,000 pounds of ammonia were released from the plant's refrigeration system as a result of the blast.

At the time of the incident, an employee of Energy Systems Analysts, a North Carolina firm under contract to ConAgra, was purging a new 3-inch gas line in preparation for commissioning a heater. Purged gases were vented directly into the utility room. Although a number of people noticed the smell of gas, purging was continued without gas detectors.

In the safety bulletin, CSB urged companies to ensure that their personnel and contractors vent purged gases directly to a safe outdoor location whenever possible.

Read more at http://www.chemsafety.gov.