When Linda Erskine looked outside her window last week, she saw an intense flare from the Mossmorran petrochemical plant in Fife. The flaring, which she says collapses night into day, can be seen more than 20 miles away in Edinburgh.

Erskine, a local Labour councillor, describes living in Lochgelly, a former mining community neighbouring Mossmorran, as unpleasant. “When that flare goes, the house does vibrate. For me it’s something akin to a Nimrod [maritime patrol plane] landing on top of your house. The first time I went out to see if there’s a helicopter flying overhead.”

Residents, who formed a local action group, are calling on the government to set up an independent inquiry into the health, social, and environmental impact of what they describe as an “ageing” plant, but this demand has been ignored. For the local community, the flaring has come to symbolise a disconnect from the Scottish government’s rhetoric about the climate emergency and what it does on the ground.

ExxonMobil’s Fife Ethylene Plant at Mossmorran began production in 1985. Flaring, a process that burns off gas that cannot be processed, can last for several days. As well as planned flaring events, unexpected flaring also occurs as a safety mechanism. It’s legal on the site that ExxonMobil shares with Shell Fife NGL, but the company has a duty to mitigate the impact it can have on local communities.

Last April, the Scottish environmental agency (Sepa) launched a criminal investigation into ExxonMobil because of unplanned flaring. The investigation follows “final warning letters” issued to ExxonMobil in April 2018 regarding flaring that was found to be “preventable and unacceptable”.

“In our bedroom, which faces towards Mossmorran, it’s impossible to keep the light out. It’s a nightmare,” said Joe Purves, a 69-year-old recently retired accountant who has lived in Lochgelly for 45 years. He believes the frequency and severity of the flaring has got worse over the last few years.

“The community are told when there’s going to be planned flaring, but it’s the fact the emergency flaring keeps on taking place,” said Linda Holt, an independent councillor at Fife council. “They always say it’s ‘process upset’ but everyone knows it’s because something has gone wrong. And things have gone wrong more in the last few years because the plant is ageing.”

Last summer, the plant was shut down to address the mechanical issues the company was having with its boilers and implement preventive work to improve the plant’s reliability. But unexpected elevated flaring occurred within a month of the plant reopening in February, sparking widespread anger.

Chris Dailly, Sepa’s head of environmental performance, said the watchdog had made it clear ExxonMobil needed to invest further in flaring mitigation technologies and given the company a timeline for compliance. “We’ve been clear that flaring has been unacceptable and that compliance with Scotland’s environmental rules is non-negotiable,” he said.

While 42-year-old James Glen, a graphic and web designer who set up the Mossmorran action group in 2017 with Holt, welcomes Sepa’s investigation, he argues it’s not enough. The action group calls for an independent inquiry that looks at health, site safety, and social issues. More than 2,000 people have written to the Scottish environment secretary, Roseanna Cunningham, echoing the action’s group demand.

A spokesperson for the Scottish government said that as Sepa was concluding its investigation, it “would not be appropriate nor helpful for ministers to interfere in independent regulatory decisions, particularly while enforcement investigations are ongoing”.

Glen accuses the Scottish government of “hiding behind Sepa” and said it should come to meet the community to discuss their concerns. Erskine said Holyrood is already losing credibility on the issue. “We should be looking after our constituents, not big business. Our job is the safety and wellbeing of the people that live here. If that plant had been any place near Edinburgh, it would have been shut down.”

Glen says the community’s concerns about their health had long been dismissed until a 2019 NHS Fife report, which he believes just scratches at the surface, concluded “it is clear that the degree of physical and psychological disturbance caused to people in the vicinity of Mossmorran has been considerable”.

The report noted the most common health-related concerns among local residents were anxiety, respiratory issues such as asthma, sleeping difficulties, and headaches. It found no evidence of higher than expected cancer rates, while 32 Sepa’s air quality reports demonstrate no breach of the UK air quality standard.

Stuart Neill, the plant’s public affairs manager, said: “We very much regret any concern that flaring may have caused to members of the local community. The safety of our people and neighbours is our most important priority and the ability to flare is a critical part of the plant’s multiple safety mechanisms.”

Neill added that the plant is one of the youngest facilities of its kind in Europe and as well as investing £20m annually in maintenance, this year the company would be investing an additional £140m to upgrade infrastructure to improve operational reliability and reduce flaring.

Glen set up an impact map so residents can report health, social or environmental issues related to Mossmorran. There have been 363 incidents added so far. One report from a resident in Edinburgh notes: “I genuinely thought tonight that there had been an explosion at the plant given the intensity [of the flaring].” Another writes: “If we see it as far away as North Berwick what must it be like up close?”