Scotland’s environmental watchdog has launched an investigation into unplanned flaring at a chemical plant.

The flaring began on Easter Sunday at the ExxonMobil Chemical Ltd facility at Mossmorran in Fife.

The Scottish Environment Protection Agency (Sepa) said it had received an unprecedented 600 complaints to its hotline from members of the public reporting a chemical smell and rumbling noise.

A formal investigation was announced as flaring entered its fifth day at the ethylene plant.

Sepa said flaring was an important safety mechanism and permitted through certain conditions but the latest incident comes after the company was served with final warning letters last year.

The watchdog found the flaring was “preventable and unacceptable”.

Flaring at Fife Ethylene Plant
Flaring at the Fife plant has entered a fifth day (Jane Barlow/PA)

Sepa chief executive Terry A’Hearn said: “In addition to working hard to ensure ExxonMobil brings a halt to the flaring as quickly as possible, we have also launched this investigation into the incident.

“The unprecedented number of complaints we have received is a clear message and it’s one that we have heard powerfully and clearly.

“I want to thank everyone who has taken the time to help us understand the impacts of this flaring and I encourage people to continue to report to us.”

He added: “The Mossmorran complex is a major industrial facility, where this type of flaring is a legitimate safety mechanism, but it’s been happening too often, and the current level and extent of the flaring from ExxonMobil Chemical Limited is unacceptable.”

ExxonMobil said the flaring was caused by a fault in a section of cable that resulted in the plant being moved to fail-safe mode, following standard operational procedure.

Plant manager Jacob McAlister said operators were committed to working constructively with Sepa and were already undertaking their own investigation.

Mr McAlister said: “As Sepa acknowledges, flaring is an important and permitted safety mechanism.

“There is no cause for concern in relation to air pollution and associated heath – as confirmed by Sepa’s own monitoring – the flare discharge being essentially water and CO2 from the combustion of process gas and steam.

“Incidents of unplanned elevated flaring at the plant are very rare, representing just 2% of our entire operational time in the past 10 years and with no increase in either frequency or volume.

“But when elevated flaring occurs, we absolutely understand its impact on communities.

“As such, we will continue to strive to minimise impact by reducing unplanned events and duration.”

He added: “Our team is working day and night to safely bring the plant back to normal operations and minimise both flaring and timescales.”

The Scottish Greens said the Scottish Government should step in.

Mark Ruskell MSP said: “In my book, when a final warning is breached, fines or other sanctions should follow.

“The Government must now take firm action against those responsible.

“We also need to go beyond the technical investigation and look at the real social impacts these flaring incidents have on people’s health and well-being.”