Mossmorran and Braefoot Bay complexes

Mossmorran Hub

Report flaring using our online web form

Page contents

April 2019 flaring event
Mossmorran Complex investigation update

Mossmorran newsletter
Flaring at Mossmorran - previous updates

Historical flaring data
Site activities
Air quality and SEPA position statement
Community liaison
Incidents, complaints and enquiries
Frequently asked questions

Useful documents

SEPA monitoring report for April 2019
Report on air quality monitoring 22 April

ExxonMobil Chemical Limited BAT Assessment
Shell UK Limited BAT Assessment


ExxonMobil Chemical Ltd - Final Warning Letter
Shell UK Limited - Final Warning Letter


ExxonMobil Chemical Limited variation (2018)
Shell UK Limited variation (2018)

Mossmorran flaring community update - 17 May

  • Formal regulatory investigation into April 2019 flaring underway.
  • Over 900 complaints were received to date by SEPA’s 24 hour Pollution Hotline, one of the highest number for any single event.
  • SEPA confirms the “level and extent of flaring is wholly unacceptable.”
  • Move by SEPA follows ‘Final Warning Letters’ issued to ExxonMobil Chemical Ltd in April 2018 regarding flaring which was found to be “preventable and unacceptable”.
  • It also follows SEPA and Health and Safety Executive investigations in 2018/2019, a tightening of permit conditions and an instruction to conduct a ‘Best Available Techniques’ (BAT) assessment.
  • BAT Assessments were received from both operators on 30 April 2019 which are currently the subject of rigorous review by technical specialists.
  • BAT Assessment are now available to view on the public register via
  • SEPA today (17 May 2019) announced that further permit variations will be served on ExxonMobil Chemical Limited and Shell UK Limited to design a programme of monitoring to assess the impacts of flaring on the local community and the environment.
  • Whilst subject to a formal regulatory investigation, SEPA has a full range of enforcement powers available and will utilise these to require the impact of flaring be reduced

The unprecedented number of complaints we received is a clear message that the impacts on people’s lives is a major concern. SEPA has heard this message powerfully and clearly.

Full regulatory investigation

On Sunday 21 April SEPA received complaints from members of the public about flaring from the Mossmorran Complex. The flaring continued until Saturday 27 April.

A formal regulatory investigation into April 2019 flaring is underway which will take time to complete. The nature of a live investigation means there is some information that cannot be provided as quickly as people would like.

We appreciate this can be frustrating, but ask that you understand that gathering and protecting potential evidence is of the utmost importance.

SEPA officers have already contacted some members of the public who contacted us to record the impacts this flaring had on them. Understanding the real impacts provided by local communities, families and individuals is vitally important and this work is ongoing.

Following completion of the investigation SEPA will use its enforcement policy to decide what action should be taken. SEPA has a range of enforcement options including serving notices requiring specific action to be taken through to the submission of a report to the Crown Office and Procurator Fiscal Service recommending prosecution of an environmental offence.

Requirement for a programme of monitoring

SEPA today (17 May 2019) announced that further permit variations will be served on ExxonMobil Chemical Limited and Shell UK Limited to design a programme of monitoring to assess the impacts of flaring on the local community and the environment - including air quality, noise and vibration.

We expect there to be a high level of community engagement in the development of the programme.

The companies will be expected to consult widely to ensure:

  • monitoring will provide the information required to carry out the necessary impact assessment;
  • the most appropriate technology and contractors are used to develop public confidence.

SEPA will scrutinise the proposed programme and make it publicly available. Providing it is suitably robust we will require the companies to implement it.

The date by which these proposals must be submitted will be contained within the Variations.

Best Available Techniques (BAT) Assessments

As part of the Permit Variations served by SEPA in 2018, both ExxonMobil Chemical Limited and Shell UK Limited were required to complete BAT Assessments to consider the ways in which they can prevent, or where that is not practicable, reduce the impact of flaring.

These were received by SEPA by the deadline and are available to view on the public register

While SEPA has conducted an initial review of the BAT Assessments, these are technical documents and we need sufficient time to analyse them in depth.  However, these assessments provide a significant opportunity and it is vital that both operators take this opportunity to deliver real changes.

SEPA will require the operators to take action to ensure they are using Best Available Techniques and any flaring is undertaken without unacceptable impacts on the community.

Working with partners

SEPA is working with a number of public agency partners in relation to the regulation of the of the Mossmorran complex in Fife. We will continue to liaise with the Health and Safety Executive, Fife Council, Health Protection Scotland and NHS Fife to share whatever information we can to ensure the impacts are understood and the regulatory controls are appropriate and effective.

The Mossmorran and Braefoot Bay Independent Air Quality Monitoring Review Group will also continue to play a key role and SEPA recently carried out a three month programme of continuous air quality monitoring to provide information to this group and its members. Further details are available in our April 2019 monitoring report, published on the Mossmorran Hub.

Monitoring during the recent flaring event

  • On 21 April SEPA staff attended locations around Cowdenbeath and Lochgelly to witness the flaring and experience the impacts. This work happened throughout the flaring event.

  • Our air quality and noise monitoring team were deployed in the area with SEPA CEO, Terry A’Hearn on 22 April. Further monitoring was carried out during the flaring event.

  • Information on the air quality monitoring SEPA carried out is available in our SEPA monitoring report for April 2019.

  • We will continue to develop our monitoring response in conjunction with Fife Council, NHS Fife and through engagement with the local community.


BAT Assessments received - 1 May 2019 - SEPA can confirm the Best Available Techniques (BAT) assessments from Shell UK Limited and ExxonMobil Chemical Limited were received yesterday. Following a review of the proposals, we will provide an update ahead of the community meeting on Friday 17 May - which we will attend.

Community update on Mossmorran flaring - 30 April 2019 - On Saturday, 27 April, the Scottish Environment Protection Agency was informed by ExxonMobil Chemical Limited that elevated flaring had ceased. The update followed the announcement by SEPA on Thursday 25 April 2019 of a formal regulatory investigation into the flaring from the Mossmorran petrochemical plant in Fife. Read the full Community update on Mossmorran flaring

Mossmorran flaring - 27 April 2019 - On Saturday, 27 April, the Scottish Environment Protection Agency was informed by ExxonMobil Chemical Limited that elevated flaring had ceased. Exxon further advised ground flaring was continuing ‘above normal levels’ for a ‘short period’. Read our full media release Mossmorran flaring community update

SEPA launches formal regulatory investigation - 25 April 2019 - The Scottish Environment Protection Agency has today (25 April 2019) announced a formal regulatory investigation into the ongoing flaring from ExxonMobil Chemical Limited at the Mossmorran petrochemical plant in Fife. Read the full media release SEPA launches formal regulatory investigation into ExxonMobil Chemical Limited unplanned flaring as complaints exceed 600

Mossmorran flaring - 22 April 2019 - SEPA's CEO, Terry A'Hearn, attended the air quality monitoring site in Cowdenbeath as part of our response to the unplanned flaring at ExxonMobil Chemical Ltd, at Mossmorran in Fife. Read our full statement Flaring at Mossmorran complex, Fife

Mossmorran flaring - 21 April 2019 - SEPA Officers have continued to respond across the day to unplanned flaring at the Mossmorran complex, Fife. ExxonMobil Chemical Ltd have provided an initial update advising they have stabilised the flow of steam to the flare - removing the early dark smoke. With Exxon advising flaring is likely to continue over the coming days, SEPA will continue its operational response across the duration of the incident, including re-deploying air quality monitoring equipment. Whilst at an early stage we will provide as much information as quickly as possible. Report environmental incidents online at or call our 24 Hour Pollution Hotline on 0800 80 70 60.

Mossmorran newsletter

SEPA is committed to keeping the local communities around Mossmorran informed. Sign up to our newsletter to be emailed the latest updates.

Read the latest on the Mossmorran and Braefoot Bay complexes

You can read previous Mossmorran newsletters online

Mossmorran Complex investigation update - 27 February 2019

SEPA has completed its investigation into a number of unplanned flaring events at the Mossmorran Complex during 2017 and 2018.

Whilst flaring is an important safety mechanism and is permitted through permit conditions, the impact of any flaring events must be mitigated so as not to have an unacceptable impact on local communities.

SEPA remains clear that the flaring in June 2017 was both preventable and unacceptable and Final Warning Letters were issued to ExxonMobil Chemical Ltd and Shell UK Ltd in that regard. Communities experienced further unplanned flaring in October 2017, March 2018 and again in May 2018.

Read the full Mossmorran Complex investigation update

Flaring at Mossmorran - previous updates

Please follow this link to view previous updates on flaring incidents.

Site activities

Shell UK operates the Fife Natural Gas Liquids (FNGL) Mossmorran Fractionation Plant near Cowdenbeath in Fife that extracts natural gasoline, ethane, propane and butane from natural gas liquids pumped from the St Fergus gas plant at Peterhead. Three identical processes separate the different components.

Ethane is forwarded to the adjacent ExxonMobil Chemical Limited Fife Ethylene Plant (FEP), Mossmorran where it is converted into ethylene by steam cracking.

The products from both sites are transported by pipeline or road tanker, predominantly to the Shell UK Limited and ExxonMobil Chemical Limited Braefoot Bay marine terminal on the Firth of Forth near Aberdour in Fife, where it is shipped. Some of the ethylene produced is distributed via the UK ethylene pipeline to other manufacturing plants in the UK.


Pollution Prevention and Control (PPC) (Scotland) Regulations 2012 (PPC)

Shell UK Fife NGL and ExxonMobil Chemical Limited FEP at Mossmorran and ExxonMobil Chemical Limited at Braefoot Bay are regulated under the PPC. The regulations permit and regulate many industrial activities that may pollute our environment. Licences, known as permits, set strict conditions that must be met to prevent or reduce any impact on the environment. For FNGL and FEP at Mossmorran the PPC Permits include specific conditions on flaring including a requirement to provide an incident report for any significant unplanned flaring. Similar licences are in place for ExxonMobil Chemical Limited at Braefoot Bay although these are less complex. We carry out regular inspections of both facilities and reviews monitoring and other returns to check compliance.

Annual compliance is also assessed using our Compliance Assessment Scheme and the results published on our website. For Mossmorran sites search under ‘Fife Ethylene Plant’ or ‘Fife NGL Plant’; and for Braefoot Bay search under ‘ExxonMobil Chemical Limited’.

Control of Major Accident Hazard (COMAH) Regulations 1999

The Shell UK and Exxon Mobil Chemical Limited Sites at Mossmorran and Braefoot Bay also fall under the COMAH Regulations which are jointly regulated by the Health and Safety Executive (HSE) and SEPA as the Competent Authority. Qualifying sites are divided into Lower Tier and Top Tier sites based on quantities of dangerous substances held on the site.

The Mossmorran and Braefoot Bay sites are classed as Upper Tier sites due to the quantities of highly flammable substances present. As such they must submit a Safety Report every five years which demonstrates the implementation of safety management systems to prevent major accidents and limit their consequences to people and the environment.

Further information on COMAH is available on the Health and Safety Executive website

In addition to carrying out routine regular inspections under both PPC and COMAH, SEPA has a duty to carry out investigations into incidents under both regulatory regimes. SEPA focus on the environmental aspects of incidents although there is often an overlap with safety aspects considered under COMAH by the HSE.

Air quality and SEPA position statement

Extensive air quality monitoring has demonstrated that concentrations of benzene and other hydrocarbons are consistently low in the vicinity of the facilities at Mossmorran and Braefoot Bay.

There was local concern over the perceived impact of the Little Raith Wind Farm on the dispersion of air emissions from the Mossmorran complex during normal operation and flaring. Concentrations of benzene measured in the vicinity of the plant were low throughout 2012 and are similar to those you would expect to find in a typical rural setting. The concentrations were well below the Air Quality Standards before and after the turbines came into operation.

We have published the following position statement.

Community liaison

We participate in the following external meetings with other organisations:

  • Mossmorran and Braefoot Bay Community and Safety Committee
    These community liaison meetings are held once a quarter and are attended by local councillors, representatives from local community councils, SEPA, ExxonMobil Chemical Limited, Shell UK and Fife Council. The minutes of the meetings should be made publically available to members of local communities through community council meetings, local libraries and the Fife Direct webpage.

  • Mossmorran and Braefoot Bay Independent Air Quality Monitoring Review Group
    The Mossmorran & Braefoot Bay Independent Air Quality Monitoring (IAQM) Review Group advises Fife Council regarding the quality of ambient air associated with air emissions from operations at the Mossmorran plants and the Braefoot Bay terminal facilities.

Of particular relevance are issues relating to any health concerns raised by residents within the local communities and a key role is assisting with the communication of information relating to environmental air quality. The IAQM Review Group is independently chaired and includes representatives from Fife Health Board, SEPA, Fife Council, the Institute of Occupational Medicine and community representatives. The Group meet twice per year and publishes an annual report which is available from the Fife Direct webpage.

Incidents, complaints and enquiries

Members of the public who are concerned about a potential pollution issue are encouraged to contact our pollution hotline on 0800 80 70 60. This is 24 hours a day, 7 days a week. We aim to follow up all complaints within 24 hours.

Frequently asked questions


Who is SEPA working with regarding Mossmorran?

The site is regulated by a number of organisations including the local authority, SEPA, and the Health and Safety Executive. We also consult with NHS Fife, Health Protection Scotland and Forth Ports in order to gain information and views to support our regulatory work.

You can see more about SEPA-specific regulatory activities under the section titled ‘Regulation’ above

What monitoring activity does SEPA undertake during flaring events?

Flaring events can vary from a few seconds, minutes or hours to days or even weeks. Some events are planned and some are unplanned and the root causes and impacts can vary significantly (i.e. the rate at which gas is flared, steam is managed and whether there is emission of dark smoke or not). Monitoring could not be justified on all occasions and the focus for us as a regulator is on ensuring compliance and working with the companies at Mossmorran to minimise the need to flare and to reduce the impacts.

Following the flaring events in June and October SEPA will review our arrangements for monitoring these events both proactively and reactively. SEPA will also review the monitoring undertaken by the company and if necessary we will require the company to undertake additional monitoring. We will engage with the local community to inform our view as to what is required.

Why do Shell UK and ExxonMobil Chemical Limited at Mossmorran need to flare?

The flares are part of the safety system and are used to burn off gas that cannot be processed safely due to the volumes involved or the gas being off specification. This might be due to scheduled maintenance requiring the plant to be ‘gas free’ prior to entry; or, following an unplanned operational interruption. The flare systems include:

  • two 80 metre high flares at Shell FNGL;
  • one 100 metre high flare at ExxonMobil FEP;
  • two ground flares which are operated by Shell FNGL but used by both sites as required.

How often do plants flare?

The number and type of flaring events varies year to year. These events can last just a few seconds and minutes to hours and days depending on the circumstances at the time. The primary reason for flaring is safety and events can be either planned or unplanned in nature. In years where there are more planned maintenance activities an increase in the number of flaring events can be expected.

To understand the frequency, type and duration of flaring events that occur, both operators at Mossmorran are required to provide an annual report to SEPA. A summary of the data provided to SEPA for the years 2008 to 2016 is available below (some additional comments have been taken from the Independent Air Quality Review Group reports):

This data is used as part of the regulatory controls applied by SEPA to both operators under their PPC permits. Flaring incidents must also be notified to SEPA and an incident report submitted (normally 1-2 pages in length) which SEPA then follows up directly with the relevant operator.

Under the Energy Act 1976 and Petroleum Act 1998, Shell are also required to have consents in place from the Oil and Gas Authority for flaring and venting of hydrocarbons.

What are the constituents of the flare?

The main constituents of the FEP flare are ethylene and/ or ethane. Other hydrocarbons may also be present as well as hydrogen, nitrogen and steam.

What restrictions are in place on flaring and why is the flare occasionally smoky?

ExxonMobil Chemical Limited at FEP and Shell UK at FNGL are permitted to flare for safety purposes. However, there are conditions in the PPC permits relating to flaring which aim to minimise community disturbance and pollution from flaring.

In general the visual and noise impact of flaring is minimised by using the ground flares; forward planning to maximise flaring during daylight hours; and, minimising the amount of material to be flared. However when the ground flares are not available, or the flow-rates are too great (e.g. in certain start-up or shutdown operations), then the elevated flare is also used.

Smoky flaring can be minimised by the addition of steam to optimise combustion. However, excessive steam addition can give rise to noise nuisance and must therefore be carefully managed.

Both the ground and elevated flares have restrictions on flaring in their PPC permit which prevent flaring of dark smoke for greater than 15 minutes.

Any major flaring resulting in burning of hydrocarbon above 5 tonnes per hour for a period of 30 minutes also requires 7 days prior notification to SEPA.

Any major flaring which is not notified in advance, requires the operator to follow the incident procedures in the PPC permit. This includes formal notification to SEPA without delay and a follow up investigation report within 14 days to confirm the causes of the flaring event, the environmental impact and measures to prevent a further flaring event due to similar causes.

What are the impacts to health of flaring?

A modelling study undertaken in 2009 assessed the impact of emissions during flaring and normal process emissions from Fife Ethylene Plant and Fife Natural Gas Liquids plant at Mossmorran, both separately and in combination.

The following pollutants were assessed:

  • carbon monoxide (CO);
  • oxides of nitrogen (NOx as NO2);
  • fine particulate matter (PM10 and PM2.5);
  • sulphur dioxide (SO2); 
  • volatile organic compounds (VOCs) including benzene and 1, 3 butadiene.

The study concluded that the long and short term predicted environmental concentrations of all of the pollutants considered were well within the air quality standards for the protection of human health.

The modelling work supports the findings of an earlier ambient monitoring study undertaken by FEP to assess emissions of VOCs and fine particulate matter (PM10) between 21 August 2008 and 1 October 2008.

The study was carried out by an independent contractor, The National Physical Laboratory (NPL) and all the data was submitted to the Air Quality Monitoring Review Group for independent analysis. This included a period of elevated flaring on 5 and 6 September 2008 during which specific VOC samples were collected.

Measured concentrations of PM10, benzene and 1,3 butadiene were all within the relevant air quality standards for the protection of human health.

What responsibilities do SEPA have regarding air quality?

Local authorities have a statutory duty to review and assess local air quality in their area against the air quality objectives for various pollutants (including benzene) that are in-place to protect human health. These air quality objectives are contained within the National Air Quality Strategy for England, Scotland, Wales and Northern Ireland which was last updated in 2007.

We have a statutory responsibility to ensure that regulated processes do not result in, or contribute to, an exceedence of European air quality objectives.

What is the impact to health of emissions from the Mossmorran Complex?

We are currently satisfied that the emissions from the Mossmorran complex are not having a detrimental impact on air quality in the local communities. Several modelling and monitoring studies have shown that the concentrations of benzene and other pollutants are currently well below the air quality objectives at local residential areas. This conclusion is backed up by the Mossmorran and Braefoot Bay Independent Air Monitoring Review Group referred to above.

What is the impact of Little Raith Wind Farm on the air emissions from Mossmorran?

Ambient monitoring was undertaken at Little Raith Farm, Lochgelly and Cowdenbeath between January 2011 and March 2013 by the wind farm developer Kennedy Renewables. The monitoring results indicate that Little Raith Wind farm is having no negative impact on the dispersion of air emissions from Mossmorran. Measured concentrations of benzene following the commissioning of the wind farm in September 2013 were no higher than the concentrations measured prior to installation, and were consistent with typical rural background levels.

A final report on the monitoring undertaken by the wind-farm developer, Kennedy Renewables was published in January 2014.

We published the report -  Impact of Little Raith Windfarm on air emissions from Mossmorran.