Oil giant ExxonMobil fined £267,000 after five highly flammable leaks put Fife workers at risk

ExxonMobil has been handed a £267,000 fine after inspectors found several leaks of highly flammable material had occurred at a facility in Fife.

Inspectors from the Health and Safety Executive (HSE) discovered the leaks after a routine inspection back in May 2019 at the Fife Ethylene Plant in Kirkcaldy.

A strong smell of Dimethyl Sulphide (DMS), a highly flammable liquid that irritates eyes and skin and is harmful if swallowed, was discovered during the inspection.

An operator confirmed that DMS and ethane were leaking from an overhead pipe, which ExxonMobil had known about for four months and had not taken extra safety precautions.

This prompted HSE to launch an investigation, ultimately finding that this was not a one-off and there had been an earlier leak on the same pipe in February 2018, which lasted four months before being fixed.

In total, five leaks were detected between February 2018 and September 2019, all caused by Corrosion Under Insulation (CUI).

The pipes carry highly flammable material, and left unchecked, water can get under the pipe insulation, degrading it from the inside.

The issue should be thoroughly monitored, but HSE’s investigation found the company’s inspection system was not up to standard.

Network of pipes at the Fife Ethylene Plant in Kirkcaldy. HSE

Inspectors carried out visual “scoping” checks on each pipe, and the results were fed into a computer tool alongside data on the pipe and its operating conditions.

This produced a risk score from 1 (high risk) to 4 (low risk), and the company would only investigate further if a pipe scored 1 or 2.

HSE said the visual inspections were often inadequate as overhead pipes were checked from ground level, limiting visibility.

In some cases, insulation would not be removed to allow for thorough investigations to take place.

HSE said that despite several leaks occurring, ExxonMobil failed to recognise the flaws in its inspection process.

ExxonMobil was fined £267,000 after pleading guilty at Kirkcaldy Sheriff Court on August 25.

HSE inspector Lindsey 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 ExxonMobil 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.

“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.”

An ExxonMobil Chemical Limited spokesperson said: “We have accepted responsibility and resolved a matter relating to historical corrosion under insulation (CUI) issues at Fife Ethylene Plant between 2018 and 2019. No workers, contractors or members of the public were put at risk, and the Court held that no hazard was created and no actual harm was caused.”

“We co-operated fully with the HSE throughout its investigation, including complying with all notices served, and commissioned an independent assessment. We accept full responsibility for the failures identified and have since made significant changes to how we inspect and manage corrosion risk across our operations.

“At the time of the incidents the Fife Ethylene Plant (FEP) organisation was moving to a revised and improved inspection methodology and this was successfully implemented together with a special program to address legacy challenges.”

The Fife Ethylene Plant in Kirkcaldy closed after four decades of operations in early 2026.