Repair work to a broken pump at Mossmorran should be completed today, bringing the latest unscheduled flaring to an end.
Fife Ethylene Plant has faced strong criticism since it began on Saturday night.
READ MORE Fare could last for days
Politicians, campaigners and residents have all spoken out at the impact of the noise and light intrusion.
The plant has already had one final warning from SEPA – the Scottish Environment Protection Agency – for an unscheduled flaring last summer, and there are two further incidents still under investigation.
SEPA, which has had officers on site monitoring the air quality, may now have a third investigation on its hands.
READ MORE Unscheduled flaring at Mossmorran
Sonia Bingham, plant manager, said work was progressing well to solve the latest problem and her forecast was it would be completed on Thursday.
She said: ‘‘!”My dedicated team continues to focus on returning this pump to service as quickly and diligently as possible.
“We are working tirelessly with our suppliers to achieve this, while doing everything we can to minimise the size of the flare, and any disturbance to the local community.’’
ExxonMobil said it was working closely with SEPA and again issued an apology to the community.