RALEIGH, N.C. (AP) — Federal officials are scheduled to vote Thursday evening on urgent safety recommendations in response to a deadly explosion at a Slim Jim snack factory in North Carolina last year.

The proposal before the U.S. Chemical Safety Board recommends that national and international safety codes be changed to more strongly control gas-line purging. The suggested guidelines would require gas purges outside of a building or require an approved safety plan, such as the evacuation of nonessential personnel.

The Associated Press reported in September that the board initially voted down a similar proposal from its staff. Two board members had argued that code writers should be the ones to decide on any new written rules, not the safety board.

North Carolina later voted to enact emergency changes to its code, adopting the new safety suggestions. Current national safety codes, developed by a committee convened by the National Fire Protection Association and the American Gas Association, say gas purges "shall not be discharged into confined spaces or areas where there are sources of ignition unless precautions are taken."

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.

Board members will hold a public hearing Thursday evening in Raleigh to discuss their preliminary findings from the investigation. The safety board is using the event to take testimony from outside experts about safety issues raised by blast.