By OGJ editors
WASHINGTON, DC, Jan. 19 -- The US Chemical Safety and Hazard Investigation Board (CSB) Friday said it would not conduct a full investigation of a recent chemical accident at a 10-year-old petrochemical plant owned by Huntsman Petrochemical Corp. in Port Neches, Tex.
CSB investigators spent 2 days at the plant site last week, near the Louisiana border (OGJ Online, Jan. 15, 2003).
The Jan. 11 chemical fire burned two plant workers and caused minor injuries to six others. Four workers, including the two second-degree burn victims, were treated and released at local hospitals.
Board investigators say the fire occurred as workers prepared a process pipe for scheduled maintenance within a 27,000 b/d unit that produces the fuel additive methyl tertiary butyl ether (MTBE).
CSB officials said plant personnel did not know at the time that the pipe contained residual feedstock chemicals. As part of the shutdown, workers directed steam through the pipe and inadvertently caused the residual chemicals inside to overheat and decompose. Accumulating pressure ruptured the pipe, releasing a flammable vapor cloud that then ignited, investigators said.
The pipe involved in the accident was seldom used at the 10-year-old facility, CSB said. After its last use in September, the pipe was purged with nitrogen gas, but owing to the pipe's design, not all liquid chemicals were removed.
In addition to the CSB, a team from Huntsman has been investigating the incident.
"Huntsman has already instituted significant corrective actions in response to Sunday's fire and is surveying the rest of the plant to determine if similar conditions may exist elsewhere," said CSB lead investigator John Vorderbrueggen. "We appreciate Huntsman's excellent cooperation with our team and look forward to reviewing the results of their completed investigation."
"This unfortunate accident emphasizes once again the importance of designing lines and equipment to facilitate safe plant operations," said CSB Chairman Carolyn W. Merritt. "Critical equipment should be designed so that workers can verify the absence of hazardous material before undertaking maintenance."
The CSB is an independent federal agency charged with investigating industrial chemical accidents. The board does not issue citations or fines but does make safety recommendations to plants, industry organizations, labor groups, and regulatory agencies, including the US Environmental Protection Agency and the US Occupational Safety and Health Administration.