INEOS fined £400,000 for 2017 Grangemouth gas leak

07 May 2021

Petrochemical giant INEOS has been fined £400,000 after a gas leak from a cracked pipe created a potentially explosive gas cloud over its Grangemouth plant in May 2017. INEOS admitted in court that its safety inspections had failed to identify a 10 inch (25cm) long corroded section of pipe which allowed a leak of ethylene gas.

Image: Richard Webb/Geograph.co.uk

Around 17 tonnes of flammable ethylene gas leaked from the pipe over a period of several hours, Falkirk Sheriff Court heard. The leak was first detected at around 11:50 before the cloud eventually dispersed around 21:45.

At the time of the incident, 97 workers were on site and had to be led to safety by emergency services. Several local roads were closed as firefighters worked to create a “wall” of water to prevent the ethylene gas from reaching the Grangemouth plant’s furnaces. No one was injured in the incident.

Falkirk Sheriff Court was told that the section of corroded pipe had been wrongly-identified as “not high-risk” and was therefore not subjected to insulation strips as part of the site’s inspection programme. This caused a process of “chloride-induced stress load corrosion cracking."

Health & Safety Executive (HSE) and Crown Office and Procurator Fiscal Service (COPFS) investigators found that the initial alarm was raised by an INEOS employee who heard safety valves being triggered automatically. The employee attempted to manually close an emergency operating valve but was told that several gas detectors were sensing a leak at ground level and the plant was being evacuated.

Prosecutor Gavin Callaghan told the court that the leak precipitated the formation of a flammable gas cloud of around 65,000 cubic metres, roughly the equivalent of 26 Olympic-sized swimming pools. The cloud reached ground level, but the plant’s emergency plan was implement to ensure that there was no ignition, Callaghan added.

Solicitor Paul Marshall, representing INEOS, said that the company's emergency response had minimised the risk of explosion and the “isolated incident” was the result of “shortcomings in what we otherwise a comprehensive inspection regime.”

In court, Sheriff Wyllie Robertson said the incident was categorised internally as the highest category of major incident where there is a risk beyond the site and boundaries. Robertson added that the significant risk was of the ethylene gas igniting, particularly in light of the proximity of the furnaces. If the vapour cloud had ignited, thermal effects and a blast wave could have been generated, resulting in a risk of death, Robertson said.

INEOS pleaded guilty to failing to take steps to prevent the incident which goes against the 2015 Control of Major Accident Hazards Regulations. IENOS’s fine was reduced from £500,000 after the company submitted an early guilty plea.

The Grangemouth site, located by the estuary of the River Forth in central Scotland, covers about 1,700 acres and employs more than 1,300 people. The site includes petrochemical plants and an adjacent oil refinery with a capacity to process about 200,000 barrels of crude per day.