OSHA issues bulletin on carbon monoxide explosion hazards in electric arc furnaces

Washington – OSHA has released a bulletin with information on how to protect workers from carbon monoxide explosion hazards related to electric arc furnaces in the steelmaking industry.

The furnaces melt and refine scrap metal at about 2,900° F. Although water explosion hazards are well known, carbon monoxide explosions are an emerging concern, as the industry uses the furnaces more to melt and purify scrap during recycling, according to the bulletin.

The carbon monoxide concentration in the furnace headspace should be checked and managed to prevent it from arriving at the explosive range of 12.5 percent to 74.2 percent, the bulletin states. OSHA urges employers to recognize small carbon monoxide explosions as near misses and investigate them.

The bulletin explains how to prevent explosions and describes a 2013 incident that injured three workers. It also provides guidance on protecting workers, including:

• Make sure engineering controls protect against maximum potential blast overpressure, heat gradients and struck-by hazards.
• Create and carry out written procedures for workers to “stand behind shields or shelters” on the furnace floor or to stay in the control booth.
• Develop and execute written procedures to determine and control excess carbon monoxide concentrations in the headspace.