New petrochemical plants intended to improve city environments by producing “lead-free” petrol have created another, more deadly, environmental hazard. Accidents at the plants could lead to lethal clouds of hydrofluoric acid (HF), putting “tens of thousands at peril”, according to the Washington-based Environmental Policy Institute.
The new process for making unleaded petrol involves using HF to achieve high octane ratings without adding lead. But HF is one of the most corrosive chemicals in existence, capable of eating away at glass and dissolving most metals. Dr jag Cook, from Britain’s National Chemical Emergency Group — which is responsible for mopping up any major toxic spills in the UK — said: “HF is about the only chemical that frightens me.”
Demand for unleaded petrol is expected to grow dramatically. A major new HF plant is being built by Shell at Stanlow, Cheshire, and will start operation in about six months time. It will be about the sixth such plant in Britain. Another is run by Mobil at Coryton, Essex. The location of the others is, according to the Health and Safety Executive, officially secret.
Recent trials and several accidents in the last year in the US have shown that industrial HF sites are a major threat to public safety. An HF leak on 30 October 1987 at the Marathon refineny in Texas City left 700 people in need of urgent medical treatment. It was only luck that prevented the accident from being the major industrial catastrophe of the year.
Dr Fred Millar of the Environmental Policy Institute said: “The release was from the vapour space of a storage tank. If the same release had been of HF liquid, thousands would likely have died in the ensuing gas cloud. It would have been our Bhopal.”
Nonetheless no new regulations were introduced — and a few months later another HF explosion occurred at Mobil’s refinery in Torrance, Callifornia. This led to a raging 41-hour fire and millions of pounds worth of damage. In March this year, there was a third HF leak, this time in Tulsa, Oklahoma. The disaster at the Sun Company refinery there produced a three-mile-long cloud which engulfed the town. Only a prompt evacuation limited the casualties to 36 people (none fatal).
A US government test at a desert site in 1986 showed that even a relatively small liquid HF accident would remain lethal for five miles.
A report written after the Torrance accident suggested that “the consequences may be so great as to warrant regulations to direct industry to phase out its use or substitute processes with less environmental hazards.” US research has shown that there are alternative processes.
Although Friends of the Earth have only recently taken up the issue, it was, said FoE specialist Andrew Lees, “high time this stuff was brought to public attention”.