RALEIGH, N.C. (AP) — Federal officials voted Thursday night to adopt urgent safety recommendations in response to last year's deadly explosion at a Slim Jim snack factory in North Carolina.

The U.S. Chemical Safety Board approved the recommendations Thursday night by a 2-1 vote taken following a public hearing in Raleigh.

A statement on the board's Web site said the recommendations urged the National Fire Protection Association, American Gas Association and the International Code Council to strengthen the national fuel gas code provisions on purging.

Specifically, the proposal called for gas purges outside of a building or require an approved safety plan, such as the evacuation of nonessential personnel.

The June explosion at the ConAgra Foods Inc. plant in Garner killed four people and injured dozens of others. A settlement last month between ConAgra and the state Labor Department said a contractor released a mixture of pressurized gas and air into an enclosed room while installing a natural gas-fired water heater.

ConAgra agreed to pay $106,000 for workplace safety violations.

Safety board staff identified similar explosions that involved the purging of gas lines, including a May 2008 incident during the construction of a San Diego hotel that injured 14, an August 2007 explosion at a hotel in Cheyenne, Wyo., that injured two, and an explosion at a Porterville, Calif., school that burned two plumbers in November 2005. They also noted another North Carolina incident — a 1997 explosion at a fitness center in Cary that injured six.

Donald Holmstrom, a CSB investigations supervisor, said the agency was also investigating whether there was a problem with putting an explosive hazard in the middle of the ConAgra building instead of on the structure's outskirts. He said even "a fairly modest" explosion would have caused 11-ton sections of the building's roof to collapse.