Mossmorran and Braefoot Bay complexes

Mossmorran Hub

On 8 June 2018,the Scottish Environment Protection Agency (SEPA) and the Health and Safety Executive announced a joint investigation into ExxonMobil Chemical Ltd and Shell UK Limited, the operators of the Mossmorran petrochemical plants in Fife.

The move followed the serving of Final Warning Letters on both companies by the agency in April 2018 related to “preventable and unacceptable” unplanned flaring during June 2017. 

SEPA Chief Executive, Terry A’Hearn, also announced operating permit variations were to be served on ExxonMobil Chemical Ltd and Shell UK Limited following a review announced in April, to strengthen noise and vibration controls. 

With the operating permit variations now served on both companies, the documents are available to download and view, as per our commitment.

Mr. A’Hearn listened carefully to first-hand accounts from the community and their elected representatives both at last week’s stakeholder meeting and again during the Scottish Parliament debate.

Following the publication of the variations Terry A’Hearn said:

“Every day, SEPA works to protect and enhance Scotland’s environment and compliance with Scotland’s environmental rules is simply non-negotiable.  

“We were clear that unplanned flaring in June 2017 was preventable and unacceptable and we issued final warnings to both companies in that regard.  We listened carefully to community calls for a root and branch review and have taken action to begin the joint investigation with the Health & Safety Executive. 

“The permit variations we have now served on ExxonMobil Chemical Ltd and Shell UK set out what each operator must do under law. They include legally binding conditions requiring them to take all appropriate preventative measures now against noise and vibration emissions through the application of Best Available Techniques, so no significant pollution is caused.  They also require a refreshed assessment of the Best Available Techniques likely to require investment at both facilities. 

“SEPA will be holding review meetings at key stages to ensure progress is made to the timetable. These meetings will involve senior executives from SEPA and both companies.” 

SEPA's CEO, Terry A'Hearn, talks to the joint investigation by SEPA and the Health and Safety Executive into Mossmorran complex following April ‘final warning’ letters for environmental non-compliance.

Details of the October, March and May flaring incidents and monitoring data remain under investigation to avoid prejudice to future enforcement action.

Mossmorran newsletter

SEPA is committed to keeping the local communities around Mossmorran informed. Sign up to our newsletter to receive the latest updates in our activities and the stages of the investigation being undertaken following the flaring incident in June.

Read the latest on the Mossmorran and Braefoot Bay complexes

You can read previous Mossmorran newsletters online or watch the video versions.

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 has recently been 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.