Mossmorran is back in the spotlight after another unscheduled flaring.
Emergency services were called to the plant as a precautionary measure on Saturday as operators ExxonMobil tried to fix a mechanical pump.
No fewer than seven fire appliances were sent to the scene.
A Scottish Fire and Rescue Service spokesman said the incident was dealt with mainly by ExxonMobil Chemical but firefighters remained for more than three hours as a precaution and to advise on ventilation.
ExxonMobil Chemical again apologised to the community after Saturday’s flaring.
It said it was working to resume normal working conditions ‘‘as soon as possible.’’
Unscheduled flaring at the plant has sparked a huge backlash over the last few years, resulting in SEPA – the Scottish Environmental Protection Agency – to issue a final warning in relation to an incident in June 2017.
SEPA has two further investigations yet to complete, and its officers are aware of this latest incident.
Officers are on site monitoring and assessing the local impact, but the fall-out has started already.
Mark Ruskell, Green MSP, tweeted: “Another unacceptable incident at Mossmorran yesterday. Awaiting a statement from SEPA on enforcement and monitoring action taken.’’
He added: “Final warning means final warning.’’