Buncefield fire

Hertfordshire Oil Storage Terminal (Buncefield)

Company type	Joint venture
Industry	Oil storage
Headquarters	Hemel Hempstead , England, United Kingdom
Area served	United Kingdom
Owner	Total UK Limited (60%), Texaco (40%)

The Buncefield fire was a significant event at the Hertfordshire Oil Storage Terminal, located near the M1 motorway in Hemel Hempstead, England, which began at 06:01 UTC on 11 December 2005. This facility ranked as the UK's fifth-largest oil-products storage depot, holding approximately of fuel. Ownership was divided between Total UK Limited (60%) and Texaco (40%).

The initial and most powerful explosion took place close to tank 912, setting off a chain reaction that engulfed 20 large storage tanks in subsequent blasts. Emergency responders declared a major emergency by 06:08 and immediately initiated firefighting operations. The explosion originated from the ignition of a fuel-air mixture within a vapour cloud caused by leaking petrol. The British Geological Survey measured the blast's intensity as 2.4 on the Richter scale.

This event represented Europe's largest peacetime explosion of its category and was the most severe incident in the UK since the 1974 Flixborough disaster. The flames were brought under control by the afternoon of 13 December, although one tank reignited that evening and was allowed to burn out naturally.

In response, the Health Protection Agency alongside the Major Incident Investigation Board issued safety recommendations aimed at improving prevention of fuel leaks and management of flammable vapours to safeguard facilities and minimize environmental impact.

Explosion and fire

At 06:01 UTC on Sunday, 11 December 2005, the first and most intense explosion occurred near tank 912. This initial blast triggered additional explosions that eventually involved 20 large storage tanks. The event was classified as an unconfined vapour cloud explosion with exceptionally high force, also identified as a fuel-air explosion. Due to an atmospheric inversion layer, these explosions were audible up to away, with reports extending from Belgium, France, and the Netherlands.

The British Geological Survey recorded this incident as having a magnitude of 2.4 on the Richter scale. Residents were awakened as far away as south London and Wokingham, approximately away, where the shockwave was felt. Additional explosions occurred at 06:27 and 06:28.

Eyewitnesses miles from the site reported seeing flames reaching hundreds of feet in height; the smoke plume was visible even from space and as far north as Lincolnshire, about away. Damage included shattered windows in buildings such as Holy Trinity church and Leverstock Green School, distorted doors, and a warehouse wall destroyed over away. Buildings in nearby St Albans also sustained damage; Townsend School was closed for repairs, and a window was blown out of St Albans Abbey, roughly away.

Multiple office buildings experienced nearly complete window loss due to the blast. The timing before working hours likely contributed to limiting casualties. Vehicles in proximity caught fire, and at least one residential roof was blown off. Authorities evacuated structures because of smoke hazards, potential further detonations, and concerns over structural integrity.

There were 43 injuries reported; two individuals required hospital treatment for respiratory issues but did not suffer life-threatening conditions. Initial media claims of eight fatalities were unsubstantiated; all personnel on site were accounted for.

By 14:00 on 12 December, Hertfordshire police, fire departments, and local MP Mike Penning confirmed seven fuel tanks remained intact but remained vulnerable if the fire expanded.

Containing the Fire

At 06:08, a major incident was declared, mobilizing an extensive firefighting operation involving up to 25 fire engines, 20 support vehicles, and 180 firefighters. Around 150 firefighters arrived promptly and began containment efforts by 08:20 on 11 December, deploying large amounts of foam. The event, occurring near junction 8 of the M1 motorway, necessitated road closures and the establishment of a public safety perimeter. This blaze was considered possibly the largest single-location fire ever managed by a fire service, resulting in foam supplies being sourced from across the country.

Initial foam application was postponed due to concerns about water contamination. Six high-capacity pumps drew 25,000 liters of water per minute from a reservoir located 1.5 miles away, supported by six booster pumps. Firefighting foam was applied at a rate of 32,000 liters per minute for over four hours before the rate was decreased. By midday, half of the twenty individual fires had been extinguished.

By 16:30 on 12 December, two additional tank fires were brought under control; however, a previously extinguished tank ruptured and reignited, posing a threat to nearby tanks. This development led to renewed closures of the M1 motorway and an expansion of the exclusion zone, with firefighters temporarily withdrawing for risk evaluation.

Operations recommenced around 20:00 with the objective of extinguishing all fires overnight. Early on 13 December, damage to another tank caused a brief retreat before firefighting resumed at 08:30. By midday, only three fires remained active, including the largest tank blaze. Clergy visited crews on site to provide support during command operations.

Firefighters anticipated complete extinguishment by the end of 13 December. The smoke plume significantly reduced in size, indicating increased mixing with water vapor. By late afternoon, all major tank fires were extinguished though some smaller flames persisted. Hertfordshire deployed 75% of its firefighting resources with assistance from sixteen other brigades. Overall coordination was managed from Hertfordshire Constabulary headquarters in Welwyn Garden City.

A new fire emerged early on 14 December; however, firefighters decided to allow it to burn out naturally due to risks associated with petroleum vapor re-ignition. Deputy Chief Mark Yates identified escaping petroleum vapor as the probable cause of the initial explosion and subsequent fire.

Smoke Plume

The dense black smoke plume, visible via satellite imagery, drifted at approximately altitude towards Reading and Swindon, spreading over much of South East England.

This smoke contained hydrocarbon particles that act as irritants but possess low toxicity and are unlikely to cause lasting health effects. The Met Office issued warnings that rainfall during the night of 11 December could bring smoke particles back to ground level.

The fire resulted in 244 people seeking medical attention, predominantly on the first day. Of these individuals, 117 exhibited symptoms related to the incident, including 38 members of the public. Most hospital visits were precautionary assessments for rescue personnel; among emergency workers, 63 reported respiratory issues with about half experiencing sore throats.

During the initial two days, intense heat caused the plume to be highly buoyant, allowing it to rise and minimizing ground-level impact. As fire intensity waned, buoyancy decreased, potentially increasing smoke concentrations near the surface. By 12 December, smoke had reached northern France and was predicted to arrive in northern Spain by the weekend.

To examine the plume’s composition and behavior, the Facility for Airborne Atmospheric Measurements—operated by NERC and the Met Office—conducted flights on 12 and 13 December. Their analysis revealed low concentrations of carbon monoxide, nitrogen oxides, and ozone; soot particles constituted the primary component. The collected data aided forecasting efforts and informed emergency response strategies.

Evacuations and closures

In the Hemel Hempstead vicinity, hundreds of residences were evacuated, resulting in approximately 2,000 individuals requiring temporary housing. Emergency responders advised those in areas affected by smoke to remain indoors and keep windows and doors sealed.

Hertfordshire Police urged residents whose homes suffered damage to seek shelter with family or friends nearby. Some displaced persons found accommodation in hotels or a local shopping centre. Total, the operator of the Buncefield facility, set up a helpline and coordinated efforts with local authorities and the Salvation Army to offer lodging and assistance.

Concerns for public safety prompted the shutdown of about 227 educational institutions, libraries, and public venues across Hertfordshire and Buckinghamshire on December 12 and 13. Authorities directed citizens to consult the Hertfordshire Direct website for ongoing information.

On December 13, seventy-eight schools within Luton borough closed, alongside several in Bedfordshire, following recommendations from Hertfordshire's Health Protection Agency due to health hazards posed by the smoke plume. Normal school activities resumed by December 14.

Transport disruption

The event took place near junction 8 of the M1 motorway, which was subsequently closed between junctions 12 and 6a—covering a significant stretch shortly thereafter. Adjacent routes, including the former M10 motorway (now incorporated into the A414 road), were also shut down.

Panic buying led to long queues at local petrol stations; however, a spokesperson from the Department of Trade and Industry reassured that no fuel shortage was anticipated.

The oil terminal provided 30% of Heathrow Airport’s fuel supply. As a consequence of the fire, Heathrow implemented fuel rationing measures, compelling some long-haul flights to destinations such as Australia, the Far East, and South Africa to make additional refueling stops at Stansted Airport or other European airports. Short-haul flights were instructed to carry sufficient fuel for return journeys prior to arrival at Heathrow. Certain aircraft faced restrictions limiting them to only 40% of their typical fuel capacity. Fuel shortages continued for several months following the explosion.

Business disruption

Within the Maylands Industrial Estate, the most severe damage affected the Northgate Information Solutions headquarters and the Fujifilm building, both rendered unusable. Demolition of the Fujifilm site commenced shortly after and was finalized by June 2006. Nearby properties including Catherine House, Keystone Distribution, 3Com Corporation, and RO buildings also endured significant damage. ASOS suffered losses amounting to £5 million in stock and was unable to trade during the critical Christmas shopping period. In total, six buildings were demolished while thirty others required extensive repairs before being reoccupied.

The loss of equipment at Northgate caused multiple hosted websites, including that of the Labour Party, to become inaccessible. Addenbrooke’s Hospital in Cambridge experienced IT system disruptions as well, temporarily resorting to manual procedures for patient admissions and discharges.

Several businesses encountered restricted access to their premises despite their buildings remaining largely intact. Local criticism emerged concerning developments near the depot site, which had originally been isolated but over time became surrounded by residential and commercial properties.

Contamination of Groundwater

In May 2006, Three Valleys Water identified the persistent and hazardous fluorosurfactant perfluorooctane sulfonate (PFOS), commonly used in firefighting foams, in groundwater near the Buncefield location. No water from this particular well was supplied to the public, and a nearby well was shut down as a precautionary measure. PFOS is recognized for its health risks, and its usage was on the verge of being prohibited by government regulation.

Just prior to this disclosure, the Drinking Water Inspectorate raised the permissible PFOS concentration in drinking water, which drew criticism from Hemel Hempstead MP Mike Penning. He accused authorities of modifying standards to accommodate increasing PFOS levels locally. The majority of fuel combusted rather than seeping into the soil, thereby limiting contamination of both land and aquifers.

Investigation

The Health and Safety Executive (HSE) and the Environment Agency launched a government-led investigation; however, a full public inquiry was not convened. The investigation board included notable members such as Tony Newton, Baron Newton of Braintree, fire safety specialist Dougal Drysdale, medical authority Dr Peter Baxter, alongside representatives from the Environment Agency and HSE. Its mandate prioritized identifying immediate causes without attributing blame to avoid influencing ongoing legal proceedings.

The Major Incident Investigation Board released an initial progress report on 21 February 2006 that outlined the event timeline and emergency response but did not analyze causes. A subsequent report issued in April 2006 examined environmental consequences.

On 9 May 2006, a detailed chronology leading up to the explosion was presented: Tank 912 at the depot began receiving unleaded petrol from Coryton Refinery at 19:00 on 10 December 2005. By midnight, tank readings appeared normal; however, around 03:00 the level gauge froze despite continued filling at approximately per hour. Calculations indicated that overflow started near 05:20.

Findings suggest that a high-level cutoff switch failed to halt filling, and its associated alarm also malfunctioned. Roughly 300 tonnes of petrol escaped through roof vents into a bunded area. This resulted in rapid development of a dense fuel-air vapor cloud which breached the bund perimeter by 05:38 and extended beyond the site by 05:50. The fuel inflow rate surged sharply to about per hour before the initial explosion at 06:01.

Damage from the blast prevented determination of the ignition source; possible origins include an emergency generator or fire pump system. Investigators excluded tanker driver error or mobile phone usage as ignition factors. The explosion was not anticipated to cause significant air quality issues at ground level.

Civil Claims

Following the Buncefield explosion, approximately 2,700 claims were submitted by residents, businesses, and insurance companies. A collective group of 146 claimants aimed to initiate a class action lawsuit against Hertfordshire Oil Storage Ltd. By late 2013, claimants including insurers, small enterprises, and about 280 families sought damages potentially reaching £1 billion.

Multiple legal proceedings ensued, with the principal trial addressing liability commencing at the High Court in October 2008. Cheetah Couriers reported a revenue decline of 20% attributable to the explosion, resulting in losses estimated between £300,000 and £400,000; their premises were situated roughly 400 meters from the depot.

An initial hearing concluded in May 2008 when Mr Justice David Steel delivered a summary judgment after Total and Hertfordshire Oil Storage Ltd acknowledged negligence contributed to the incident. During the main trial, Total UK contended that responsibility lay with the duty supervisor and denied any civil or criminal liability, asserting it could not have reasonably predicted the scale of damage.

On 20 March 2009, the High Court ruled Total accountable for the explosion, affirming its control over tank filling activities at Buncefield. This decision exposed Total to damage claims approximating £700 million.

Total appealed this ruling; however, their appeal was dismissed on 4 March 2010.

Criminal responsibility

The facility is regulated under the COMAH framework, overseen by the Environment Agency alongside the Health and Safety Executive, both of which conducted inquiries into the fire incident.

In April 2010, criminal charges were brought against five companies by these regulatory bodies. Total UK and British Pipeline Agency Limited had previously admitted guilt for breaches of the Health and Safety at Work Act. By June 2010, Hertfordshire Oil Storage Ltd, TAV Engineering Ltd, and Motherwell Control Systems were convicted. TAV Engineering and Motherwell Control Systems were found culpable for failing to safeguard their employees, whereas Hertfordshire Oil Storage Ltd was convicted of neglecting to prevent major accidents and pleaded guilty to pollution offenses under the Water Resources Act.

During sentencing in July 2010, Total UK received a £3.6 million fine along with £2.6 million in costs; Hertfordshire Oil Storage Ltd was fined £1.45 million with an additional £1 million in costs; British Pipeline Agency was fined £300,000 plus £480,000 in costs; Motherwell Control Systems and TAV Engineering each received fines of £1,000. Local MP Mike Penning criticized the penalties as "insulting."

The terminal

The Hertfordshire Oil Storage Terminal (HOSL), commonly referred to as the Buncefield site, ranked as the fifth largest oil-products storage facility in the UK, boasting a capacity of approximately , which accounted for about 8% of the nation’s oil storage volume. It played an integral role within the UK oil pipeline network (UKOP), providing connections to both Lindsey Oil Refinery and Stanlow Refinery. The terminal is a vital source of aviation fuel for key airports such as Gatwick, Heathrow, and Luton. Roughly half of the site’s storage is dedicated to aviation fuel, while the remainder holds oil, kerosene, petrol, and diesel destined for petrol stations throughout South-East England. Ownership is divided between TOTAL UK Limited (60%) and Texaco (40%).

The blaze originated in "HOSL West," which was utilized by Total and Texaco for storing various fuels, as well as in the neighboring area operated by the British Pipeline Agency.

Causes

According to the 2011 findings from the Major Incident Investigation Board (MIIB), Tank 912 was being filled with petrol without dependable level monitoring systems in place. The manual gauge was stuck, and the independent high-level shut-off device was non-functional, resulting in overfilling. This caused petrol to overflow through vents, creating a vapour cloud that ignited, triggering an explosion followed by fires that persisted for five days.

Maintenance shortcomings since 2005 caused intermittent failures of the gauge, while the shut-off switch lacked a necessary padlock that would have allowed proper operational checks. Both secondary containment measures (such as retaining walls) and tertiary containment systems (including drains and catchment areas) failed to prevent contamination of groundwater by fuel and firefighting foam. The investigation underscored deficiencies in both design and upkeep of these containment structures.

Additionally, management inadequacies played a role: safety inspections were insufficient, personnel had limited control over inlet flow rates from two out of three supply sources, hindering effective fuel management. An increase in throughput led to prioritizing process operations at the expense of process safety, thereby heightening risk exposure.

Aftermath

In the wake of the event, responsibility for monitoring air quality was reassigned from the Health Protection Agency to the Environment Agency, which operates under the Major Accident Investigation Board.

Remembrance

On 10 December 2006, a commemorative service took place at Holy Trinity Church in Leverstock Green. During the ceremony, the Bishop of St Albans urged the establishment of a comprehensive public inquiry, emphasized the importance of safeguarding the local hospital’s emergency department, and encouraged the community to continue nurturing the bonds formed in response to the explosion.

Reconstruction

Restoration of the damaged portions of the site required authorization from Dacorum Borough Council. The BP section, situated away from the blast zone, experienced only minor damage but remained non-operational as of 2009. BP has considered future options for this area, focusing on resuming fuel pipeline deliveries to Heathrow Airport and evaluating possibilities for limited aviation fuel storage and motor fuel distribution. In late 2009, Total UK submitted plans for rebuilding its oil depot. Reconstruction efforts commenced in March 2013 and have been ongoing since.

Commemoration

At the roundabout marking Hemel Hempstead’s entrance stands the "Phoenix Gateway" sculpture by Jose Zavala, representing the town’s resilience and recovery following the Buncefield oil depot explosion.

See also

• 2021 Balongan refinery explosion
• 2009 Cataño oil refinery fire
• 2009 Jaipur fire
• 1987 Grangemouth Refinery explosion and fire
• 1983 Milford Haven Refinery fire

Further reading

• Buncefield in Pictures – BBC News, 14 December 2006
• Great Britain: Hertfordshire Fire and Rescue Service, Buncefield: Hertfordshire Fire and Rescue Service's review of the fire response, The Stationery Office, 2006
• Buncefield Major Incident Investigation Board, Initial Report, 13 July 2006
• Sceptre Fundraising Team, The Buncefield Explosion, Sceptre Education, 2006

External links

• Buncefield explosion prosecution
• The Buncefield Investigation Official enquiry
• Hertfordshire Constabulary Aerial photos during the fire
• Buncefield Terminal Incident HOSL website coverage
• Hemel Today High Court compensation trial coverage
• Aerial photo (January 2006) of fire aftermath
• Aerial photo of Buncefield terminal