PEMEX LPG Terminal, Mexico City, Mexico. 19th November 1984
At approximately 05:35 hours on 19 November 1984 a major fire and a
series of catastrophic explosions occurred at the government owned and
operated PEMEX LPG Terminal at San Juan Ixhuatepec, Mexico City. As a
consequence of these events some 500 individuals were killed and the
Three refineries supplied the facility with LPG on a daily basis. The
plant was being filled from a refinery 400 km away, as on the previous day
it had become almost empty. Two large spheres and 48 cylindrical vessels
were filled to 90% and 4 smaller spheres to 50% full.
A drop in pressure was noticed in the control room and also at a pipeline
pumping station. An 8-inch pipe between a sphere and a series of cylinders
had ruptured. Unfortunately the operators could not identify the cause of
the pressure drop. The release of LPG continued for about 5-10 minutes when
the gas cloud, estimated at 200 m x 150 m x 2 m high, drifted to a flare
stack. It ignited, causing violent ground shock. A number of ground fires
occurred. Workers on the plant now tried to deal with the escape taking
various action. At a late stage somebody pressed the emergency shut down
About fifteen minutes after the initial release the first BLEVE occurred.
For the next hour and a half there followed a series of BLEVEs as the LPG
vessels violently exploded. LPG was said to rain down and surfaces covered
in the liquid were set alight. The explosions were recorded on a seismograph
at the University of Mexico.
Failings in technical measures
- The total destruction of the terminal occurred because there was a
failure of the overall basis of safety which included the layout of the
plant and emergency isolation features
- Plant Layout: positioning of the
- Isolation: emergency isolation
- The terminal’s fire water system was disabled in the initial blast.
Also the water spray systems were inadequate.
- Active / Passive Fire Protection:
survivability of critical systems, insulation thickness, water deluge
- The installation of a more effective gas detection and emergency
isolation system could have averted the incident. The plant had no gas
detection system and therefore when the emergency isolation was
initiated it was probably too late.
- Leak / Gas Detection: gas detection
- Hindering the arrival of the emergency services was the traffic chaos,
which built up as local residents sought to escape the area.
- Emergency Response / Spill Control:
site emergency plan, access of emergency vehicles
Lees, F.P., ‘Loss Prevention in the Process Industries – Hazard
Identification, Assessment and Control’, Volume 3, Appendix 4, Butterworth
Heinemann, ISBN 0 7506 1547 8, 1996.
Marsh and McLennan, ‘Large Property Damage Losses in the
Hydrocarbon-Chemical Industries a thirty-year Review’, 16th Edition, Marsh
and McLennan Protection Consultants, 1995.