The willful citation issued by OSHA stemmed from the plant's water-based sprinkler system. "The application of water to burning combustible metals can result in hydrogen production and explosion," the citation said. OSHA recommended the use of a sand/salt fire suppression system instead.
Under OSHA rules, a willful violation is one committed with intentional knowing or voluntary disregard for the law's requirements, or with plain indifference to worker safety and health. The willful violation in this case carried a proposed fine of $70,000.
OSHA officials declined to make anyone with direct knowledge of the case available for a telephone interview Tuesday. But in an emailed statement, Prentice Cline, director of the agency's Charleston area office, said the sprinkler system played a major role in the accident.
"When the water from the sprinkler system made contact with the metal fire, it created hydrogen in sufficient quantity to result in an explosion and spreading of the existing fire throughout the production area," Cline said in the statement, which was forwarded though an OSHA public affairs official.
Cline also said, "It is unknown exactly what caused the initial fire, but there were conditions creating the potential for a fire, including lack of grounding and bonding of metal processing equipment, and use of spark-producing tools."
Robert Hall, lead investigator for the CSB, has previously said that an ignition of metal dust may have been involved in the incident.
Hillary Cohen, a CSB spokeswoman, said the board has contracted with a combustible dust expert and plans to test material from AL Solutions in the near future.
CSB officials have for years been recommending that OSHA adopt a broad rule to protect workers in various industries from the hazards of combustible dust. So far, OSHA has not proposed such a rule.
In its own prepared statement, AL Solutions declined comment on the OSHA citations until other investigations of the incident are completed.
The company has 15 business days from receipt of the citations to comply, ask for an informal conference with OSHA's area director or contest the citations and proposed penalties before the independent Occupational Safety and Health Review Commission.
Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.