A December report to the state’s Department of Environmental Quality indicates that human error at Axiall’s Westlake plant caused an unauthorized discharge of nearly 8,000 pounds of sodium hydroxide. The incident occurred just one day prior to the plant’s explosion and fire that sent at least 27 people to area hospitals.
Axiall’s “Unauthorized Discharge Notification Report” sent to DEQ officials on Dec. 23, states that 7,834 pounds of sodium hydroxide or “caustic soda” was released from one of the plant’s caustic transfer headers to the ground shortly after 9:30 p.m. on Dec. 19.
DEQ Press Secretary Greg Langley said the Dec. 19 incident was unrelated to Axiall’s Dec. 20 fire. “The spill was cleaned up in a timely fashion,” he said. “There was no off-site impact. We are at this time not considering any penalty or fine, but that could change if we get any information that contradicts any of that.”
In a statement to the American Press, Jon Manns, plant manager of Axiall’s Westlake facility, said the spill area was “immediately cleaned” and that the incident’s investigation is “on-going.” He added that sodium hydroxide is a chemical “used in common household products.”
Axiall’s report states that its maintenance crew installed a new valve on one of the plant’s caustic transfer headers during the day shift. During the plant’s night shift, however, Axiall’s operation’s department “placed the header back into service.” Shortly thereafter, the report states, operators in the control room “received elevated pH alarms from the sewer and investigated. Upon investigation, it was discovered that the new valve had been left open and caustic was released to the ground.”
The report states the release lasted 36 minutes. In response to the report’s inquiry about the specific remedial actions taken to stop the unauthorized discharge, Axiall said “operators immediately ceased the transfer and closed the valve.”
Axiall also reported that the caustic solution “was neutralized with acid in the process sewer” and that “all impacted sediment was removed and disposed of according to agency regulations.”
Axiall’s report states that the company “is not aware of any impact to groundwater related to these incidents.” The report also states the release “could have been prevented if the new valve installed had been closed prior to placing the transfer header in service.”
The Agency for Toxic Substances and Disease Registry defines sodium hydroxide as a “white crystalline odorless solid that absorbs moisture from the air. It is a manufactured substance. When dissolved in water or neutralized with acid it liberates substantial heat, which may be sufficient to ignite combustible materials.”
ATSDR also states that “inhalation of low levels of sodium hydroxide as dusts, mists or aerosols may cause irritation of the nose, throat, and respiratory airways. Inhalation of higher levels can produce swelling or spasms of the upper airway leading to obstruction and loss of measurable pulse; inflammation of the lungs and accumulation of fluid in the lungs may also occur.”
Neither the Department of Health and Human Services nor the Environmental Protection Agency has classified sodium hydroxide as a human carcinogen.