Release of Hydrofluoric acid from Marathon Petroleum Refinery, Texas,
USA. 30th October 1987
On 30th October 1987, a crane carrying a 50 foot section of a convection
heater dropped its load onto an anhydrous hydrogen fluoride tank within the
HF alkylation unit, shearing two lines leading to the top of the tank. This
resulted in an air release of hydrofluoric acid at the Marathon Petroleum
Company refinery in Texas City.
One line was a 4-inch acid truck loading line, and the other was a 2-inch
tank pressure relief line. The tank was at the normal operating pressure of
approximately 125 psi, so that when the incident occurred a cloud of HF was
produced which moved with the prevailing wind. The tank originally contained
35,700 gallons of AHF, of which about 6,548 gallons was released over a 44
hour period, although the majority of the release took place during the
first two hours as the tank depressurised. The release also included some
light hydrocarbons (primarily isobutane) and water vapour.
The first mitigation action was to place stationary fire monitor nozzles
and to erect a water spray curtain about 10 feet downwind of the release to
control the HF acid vapour plume.
Approximately 4,000 people were evacuated from the residential areas
threatened by the plume and the three area hospitals treated 1,037 patients,
of which nearly 100 were hospitalised. There was extensive damage to trees
and vegetation in the residential area.
Failings in technical measures
- Load dropped from crane struck storage tank rupturing two pipelines.
- Lifting Procedures: safety
Lines, I.G., ‘A review of the manufacture, uses, incidents and hazard
models for hydrogen fluoride’, HSE Contract Research Report No. 79/1995,
ISBN 0 7176 0983 9, 1995.