The issue of the unscheduled flaring, which lit up the skies of Fife and Edinburgh earlier this week, was raised by SNP MSP for Cowdenbeath Annabelle Ewing, who labelled the situation for residents “56 hours of hell” done with a “blatant disregard” for locals.
Ms Sturgeon said the concerns of residents were “entirely legitimate”.
She said: “I completely understand the community concerns in relation to this issue and I understand the frustration and anger that people in the local community will feel and I hear it expressed on their behalf by Annabelle Ewing.
"SEPA is currently looking at the cause of the flaring and how it was managed over the full duration of the incident.
"The concerns locally are clear and well understood both by government and by regulators and the Crown Office is currently considering a report submitted by SEPA into a previous incident of flaring.
"I hope it is an indication of the seriousness with which SEPA is treating flaring incidents at the plant.”
Flaring at Mossmorran was also brought up by the Green MSP for mid-Scotland and Fife, Mark Ruskell, who called on the Scottish Government to consider a full independent inquiry into the flaring, something the First Minister said she would raise with the environment secretary.
Mr Ruskell said: “I’m glad that the voices of thousands who have raised concerns has finally been heard. The First Minister has said she will look into the possibility of an independent inquiry and how to give a secure future for workers at the plant.
“This commitment is an important first step, but it comes after over a year of ministers refusing to meet with residents, ignoring calls for an independent inquiry and only a week after the Scottish Government refused to agree to my call to establish a just transition board for Mossmorran.
“I look forward to progress on this. It’s clear this fossil fuel relic cannot provide long-term jobs in the future. Communities in Lochgelly and Cowdenbeath need a short-term end to the pollution and a long-term plan to invest in alternative and future-proofed jobs for this community.”