Falkirk Sheriff Court heard that on 2 May 2017 approximately 17 tonnes of ethylene was released from the pipe. This leak precipitated the formation of a flammable gas cloud of around 65,000m³. The gas cloud was seen to move through a congested area of the plant, reaching ground level.
An investigation by the Health and Safety Executive (HSE) identified that the immediate cause of an unplanned shutdown on the compressor was due to a ‘non-routine’ maintenance activity related to the changeover of a redundant electronic control card in the compressor anti-surge system.
HSE said that the line should have been designed for all potential operating conditions and should not have failed as a result of the rapid opening of the valve and the sudden inrush of hot gas.
Ineos Chemicals Grangemouth Limited, of Chapel Lane, Lyndhurst, Hampshire pleaded guilty to breaching Regulation 5(1) of the Control of Major Accident Hazards Regulations 2015 and section 33(1) of the Health and Safety at Work etc. Act 1974. It was fined £400,000.
Speaking after the hearing, HSE inspector Mac Young said: “While there were no injuries as a result of this incident, and it was brought under control relatively quickly, the level of fine reflects the seriousness of what happened. It is important that operators of high hazard sites remain vigilant and control the risks that arise as a result of their processes to prevent major incidents.”