A seven-person investigation team from the US Chemical
Safety Board (CSB) is deploying to the site of an accident
reportedly involving the release of hydrofluoric acid (HF) at
the Citgo alkylation unit in Corpus Christi, Texas.
The team will be headed by Donald Holmstrom, director of the
CSBs Western Regional Office in Denver, and is expected
to begin work Wednesday.
According to media reports, no injuries were reported as
detectors sensing the HF set off water cannons to contain the
The alkylation unit in the 163,000 bpd refinery utilizes HF to make
high-octane blending components for gasoline. HF is highly
corrosive and toxic.
Absorption through the skin can produce fatal cardiac arrest
and inhalation causes damage to the linings of the lungs, the
On July 19, 2009, hydrocarbons and hydrogen fluoride were
suddenly released from the same unit.
The hydrocarbons ignited, leading to a fire that burned for
several days. The fire critically injured one employee and
another was treated for possible hydrogen fluoride
As a result of the 2009 accident, Citgo reported to the
Texas Commission on Environmental Quality that
approximately 21 tons (42,000 pounds) of HF released from
alkylation unit piping and equipment, but was captured by the
HF water mitigation system.
The CSBs investigation into this accident is
continuing. Investigators early on determined that during the
first day of response efforts, Citgo nearly exhausted the
stored water supply for the water mitigation system, causing
the refinery to begin pumping salt water
as a backup.
Multiple failures occurred during the salt water transfer
including ruptures of the barge-to-shore transfer hoses and
water pump engine failures.
In December 2009, the CSB issued urgent safety
recommendations calling on Citgo to immediately improve its
emergency water mitigation system in the event of another
release hydrogen fluoride.
The board also called on Citgo to perform third-party audits
to ensure the safety of its hydrogen fluoride units at its
Corpus Christi, Texas, and Lemont, Illinois, refineries.
Citgo met the requirements of the recommendations in 2011,
the CSB said.
We are launching an investigation into this accident
as we continue our investigation of the 2009 HF release event,
because of the toxic nature of hydrofluoric acid and the need
to keep it contained, or to mitigate the consequences of a
release, said CSB chair Rafael Moure-Eraso.
Approximately 50 of the nations refineries still
use HF in their alkylation units, requiring great care in its
handling," he added.
The CSB is an independent federal agency charged with
investigating serious chemical accidents. The agency's board
members are appointed by the president and confirmed by the
CSB investigations look into all aspects of chemical
accidents, including physical causes such as equipment failure
as well as inadequacies in regulations, industry standards, and
safety management systems.
The board does not issue citations or fines but does make
safety recommendations to plants, industry organizations, labor
groups, and regulatory agencies such as OSHA and EPA.