The U.S. Department of Labor's Occupational Safety and Health Administration (OSHA) recently cited Inferno Wood Pellet Inc. after a combustible wood dust explosion and fire occurred at the company's plant in East Providence, R.I., injuring a worker and partially demolishing the building. The ignition of wood dust in the plant's production room migrated to a retention bin, resulting in an explosion that spread through the building.

"While no one was killed, the potential for death and serious injury was real, present and preventable," said Patrick Griffin, OSHA's area director for Rhode Island. "The lack of safeguards allowed the initial fire and explosion to occur and spread in a chain reaction to other equipment and through the plant. If this employer had adhered to applicable OSHA and National Fire Protection Association standards, that would have helped prevent the fire and explosion from occurring and spreading."

An OSHA investigation found that employees at the plant were exposed to wood dust explosions, deflagrations or rapid combustion and other fire hazards due to inadequate or absent preventive and protective measures in the wood pellet processing system and its equipment.

Specifically, OSHA found that the retention bin lacked spark detection, explosion suppression, fire/explosion isolation and explosion venting devices. In addition, the plant's conveyor systems carrying combustible wood products lacked spark detection, fire suppression and/or fire isolation devices. Dust collection systems and dust segregation barriers were also not maintained to minimize fire sources, and an opening in the firewall between the plant's production room and chip room allowed a fireball to enter the chip room and spread the fire.

Other fire hazards identified by OSHA included the accumulation of combustible wood dust on various locations and surfaces within the plant, an incomplete and inadequate fire prevention plan, and lack of dust-tight electrical equipment where combustible wood dust accumulated.

Additional hazards involved an incomplete respiratory protection program, lack of noise monitoring, inadequate chemical hazard communication and training, excess amounts of liquefied petroleum gas stored in the building, an untrained forklift operator, and lack of procedures and training to ensure that all equipment was properly de-energized to prevent unintended activation.

Because of these and other hazards, OSHA has cited Inferno for 11 serious violations of workplace safety standards and has proposed $43,400 in fines. A serious violation occurs when there is substantial probability that death or serious physical harm could result from a hazard about which the employer knew or should have known.

"Combustible wood dust is a byproduct of the manufacturing process, and it is the employer's responsibility to ensure that proper and effective safeguards are in place and in use at all times so that incidents like this fire and explosion do not occur," said Griffin.

Inferno has 15 business days from receipt of its citations and proposed penalties to comply, meet informally with OSHA's area director or contest the findings before the independent Occupational Safety and Health Review Commission.

For more information, visit www.osha.gov.