ExxonMobil fined after ‘woeful’ maintenance of Scottish ethylene plant led to multiple leaks

EXXONMOBIL has been ordered to pay £267,000 ($361,000) over multiple hydrocarbon leaks at its ethylene plant in Mossmorran, Scotland.

The US petrochemical giant pled guilty to charges accusing them of causing five leaks of “extremely flammable” hydrocarbons at the Fife Ethylene Plant between February 2018 and September 2019. In a scathing statement following the court hearing, Health and Safety Executive (HSE) inspector Lindsey Stein said Exxon’s maintenance regime was “woefully inadequate” and that their behaviour “beggars belief”.

HSE first discovered a dimethyl sulphide and ethane leak in overhead pipework during a routine inspection in May 2019. Operators admitted they had known about the leak since January of that year but had not taken any extra precautions. Inspectors then learned that a leak in a different section of the same pipework around a year earlier had gone four months without repair. Another leak, in December 2018, released 82 t of ethane over six weeks. In all but one of the leaks Exxon continued to operate the plant without repair.

All five leaks were attributed to corrosion caused by water infiltrating between pipework and its insulation. Operators monitored corrosion by visual “scoping”, HSE found, but without fully removing insulation to have a thorough look.

Stein said: “Once we stepped in, the operator was able to identify and fix problems quickly and effectively. That tells you everything you need to know: the measures needed to prevent these leaks were reasonably practicable all along, and they should have been in place long before HSE was forced to intervene.”

Exxon announced plans to close the Mossmorran plant last November citing the UK’s “economic and policy environment” and ceased production in February this year. This followed a £176,000 fine served to the company by Scottish environment authorities over a week-long period of unplanned flaring in April 2019.

Stein said: “At a site run by one of the biggest energy companies in the world, subject to the strictest controls, and processing high volumes of hazardous material, what our inspectors found beggars belief. The failure of Exxon to properly inspect insulated pipework led to five separate leaks of highly flammable hydrocarbons, and while none of these leaks resulted in a catastrophic event, this was down to good fortune rather than good management.

“The arrangements in place to detect and prevent corrosion were woefully inadequate, and the consequences could have been far more serious.

“Systemiatic risk management isn’t just best practice, it’s a legal duty, precisely because these are high-hazard operations where the margin for error is minimal.”

The size of the latest fine has been criticised. Hazards Campaign lead Marie Monaghan told TCE it is “appalling” that the fine was not “far higher”, and that it was “irrelevant” in the context of Exxon’s g
lobal profits after tax of $29bn. “Safety regulators should be forces to be reckoned with and held in the highest regard. Fines at this level send entirely the wrong message and undermine regulation.”

An Exxon Chemical spokesperson said the company accepted “full responsibility” for the failures at Mossmorran and that they have “since made significant changes to how we inspect and manage corrosion risks across our operations”.

The latest fine comes on top of a £1m penalty served to Exxon in June after being found responsible for a 2.4 t liquid petroleum gas release at its Fawley refinery near Southampton four years ago. Two months ago, HSE ordered operators to cease certain operations in one section of the refinery because workers were not protected from dangerous concentrations of chlorine and bromine.