By ShipCalculators.com · Published 10 May 2026

MV X-Press Pearl 2021: Sri Lanka container ship fire + worst plastic pellet spill

The MV X-Press Pearl disaster of May to June 2021 off the western coast of Sri Lanka is the worst plastic pellet (nurdle) marine pollution event ever recorded and the most consequential container-ship casualty of the early 2020s, ranking alongside the MV Wakashio 2020 Mauritius oil spill as the defining environmental maritime case of its decade. The 36,000 GT, 186 metre, 2,743 TEU Singapore-flagged feeder container ship, classed by Bureau Veritas and operated by X-Press Feeders Limited of Singapore, was on her maiden commercial voyage from Hazira (India) to Colombo and onward to Singapore when fire erupted on 20 May 2021 in a deck-stowed container six rows from the bow, intensified into open-deck conflagration on 25 May, escalated through a 25 to 26 May explosion that ultimately involved approximately 1,486 containers of mixed cargo, and resulted in the aft section settling on the seabed on 11 June and the 17 June 2021 complete sinking of the hull approximately 9.5 nautical miles west of Colombo in 21 metres of water. The casualty originated in a nitric acid container leak detected during the early voyage, mishandled at successive ports, and ultimately undeclared at the level required under the IMDG Code and MARPOL Annex III packaged dangerous goods regime. The cargo manifest declared approximately 25 containers of nitric acid, 9 of caustic soda, 9 of cosmetic raw materials and 10 of EPDM rubber alongside high-density polyethylene nurdle consignments. Approximately 75 tonnes of plastic pellets were released to the marine environment, washing onto more than 80 kilometres of Sri Lankan coastline, with subsequent strandings of approximately 417 sea turtles, 48 dolphins and 8 whales in the months that followed. The Sri Lankan Government formally lodged a USD 6.4 billion compensation claim, the master and chief officer were arrested and charged under the Marine Pollution Prevention Act and Penal Code in Colombo, SMIT Salvage led the response under contract to the operator, and the classification society and Singapore flag-state inquiries proceeded in parallel. The casualty drove the 2021 IMO MEPC 76 emergency discussion, the formation of the international Plastic Pellet Loss Working Group, and the 2024 IMO PPR 11 and MEPC 81 reform proposals to bring nurdle-bearing containers within the IMDG hazard-classification regime. The X-Press Pearl is now a foundational case study in classification-society maritime-safety doctrine alongside the Costa Concordia 2012, the MS Estonia 1994, the Wakashio 2020 and the Maersk Honam 2018 fires.

Contents

Background: 2021 X-Press Pearl maiden voyage

The X-Press Pearl was on the outbound leg of her maiden commercial voyage when the casualty unfolded. Delivered by Zhoushan Changhong International Shipyard of the Zhejiang Province of China to X-Press Feeders Limited of Singapore on 10 February 2021, she had completed sea trials, taken on her first commercial complement of crew through the X-Press Feeders crewing pool, loaded her first commercial container parcel at Jebel Ali, run a short positioning leg through the Indian Ocean and arrived at the Indian deep-water port of Hazira on 15 May 2021 for cargo onload destined for the Singapore feeder hub via Colombo and an intermediate Sri Lankan call. The voyage was therefore not a routine repeat-trade movement but the very first revenue-earning rotation of a 2021-built ship in feeder service, with all of the on-boarding pressures, manifest-verification dependencies and crew familiarisation issues that entail under the ISM Code.

The casualty produced approximately 2 confirmed deaths of salvage personnel and 25 of 25 onboard crew safely evacuated by Sri Lanka Navy, Sri Lanka Coast Guard and SMIT Salvage tug crews on 25 May 2021 prior to the explosion. The casualty did not, in itself, produce a mass-casualty bridge-event of the Estonia 1994 or Concordia 2012 type. Its environmental footprint, by contrast, is the largest documented plastic-pellet release in maritime history and a comparable scale of packaged-dangerous-goods marine release to the Costa Pacifica chemical losses or the 1991 Bahia Paraiso fuel spill. The casualty triggered a Sri Lankan whole-of-government response across the Marine Environment Protection Authority (MEPA), the Central Environmental Authority (CEA), the Department of Fisheries, the Sri Lanka Navy, the Sri Lanka Coast Guard, and the Attorney General’s Department.

The vessel: container ship particulars (2,743 TEU, 36,000 GT)

The X-Press Pearl particulars, fixed at delivery in February 2021 and unchanged at the time of casualty, are summarised in the introductory data identities used throughout this article:

\text{IMO 9875343; built 2021 Zhoushan Changhong}

\text{TEU} = 2{,}743, \quad \text{GT} = 36{,}000

L_{\text{OA}} = 186 \text{ m}, \quad B = 32 \text{ m}, \quad d = 13 \text{ m}

The ship’s MMSI was 565389000, the call sign 9V8593, and the deadweight (DWT) approximately 39,000 tonnes at summer load line. The hull was a single-skin steel monohull of feeder-container configuration with five cargo holds forward of the engine room and twin tier deck stowage above the hatch covers. Container-tier capacity was nine high on deck plus six in the holds, fitted with cell guides for standardised TEU/FEU stowage, twist-lock automatic cones at deck level and lashing bridges across the main hatch covers. The ship was rated for IMDG Class 1 explosives, Class 2 gases, Class 3 flammable liquids, Class 4, Class 5 oxidisers, Class 6 toxic substances, Class 8 corrosives (under which nitric acid UN 2031 and UN 2032 are classified) and Class 9 miscellaneous dangerous goods, with a single MAN B&W 7S50ME-B9.3 main engine of approximately 11.6 MW driving a single fixed-pitch propeller and a service speed of approximately 16 knots.

The ship had no reefer-container intensive specialisation and no specific dangerous-cargo exclusion. She was purpose-built for short-sea Indian Ocean and South-East Asian feeder service to the Colombo, Singapore, Port Klang, Tanjung Pelepas, Chittagong and Mongla deep-sea hub-and-spoke architecture under the X-Press Feeders trade-lane network. The casualty therefore did not arise from any vessel-design limitation in cargo segregation or fire-fighting capability beyond the IMO industry baseline at 2021.

Built: 2021 Zhoushan Changhong China

The ship was built at the Zhoushan Changhong International Shipyard in Zhoushan City, Zhejiang Province, China, an Eastern Yangtze Delta cluster yard that has built feeder container ships for X-Press Feeders, MSC, Wan Hai and other operators since 2009. Hull number 091 was laid down in 2020, launched in 2020, completed sea trials in late 2020 and was delivered on 10 February 2021, approximately three months prior to the casualty. The Zhoushan Changhong yard issued the SOLAS Cargo Ship Construction Certificate, the SOLAS Cargo Ship Equipment Certificate and the load-line certificate at delivery, all to the satisfaction of the Bureau Veritas Recognised Organisation surveyors and the Singapore Maritime and Port Authority flag-state surveyor present at delivery. No latent-defect issue has been identified by either the BV class investigation or the Singapore flag-state Marine Court of Inquiry as causally relevant to the casualty.

Class: Bureau Veritas (BV)

The X-Press Pearl was classed by Bureau Veritas Marine and Offshore (BV), the French classification society headquartered at Neuilly-sur-Seine and a founding member of the International Association of Classification Societies (IACS). BV issued the principal class certificate at delivery in February 2021 and would have conducted the first annual class survey in February 2022 had the ship not been lost. BV also acted as the Recognised Organisation under bilateral delegation from the Singapore Maritime and Port Authority for issuance of the statutory SOLAS Cargo Ship Safety Construction, Cargo Ship Safety Equipment, Cargo Ship Safety Radio, MARPOL IOPP, IAPP, IEEC, ISPP and ISP certificates, the ISM Code Safety Management Certificate, the ISPS Code International Ship Security Certificate, the GMDSS Radio Certificate, the Maritime Labour Certificate and the BWM Convention International Ballast Water Management Certificate. The casualty therefore did not arise from undiscovered hull, machinery or fire-protection defect: the immediate cause was the mismanagement of a packaged dangerous-goods consignment during pre-loading and onboard stowage, an operational failure rather than a structural one.

Flag: Singapore (X-Press Feeders)

The X-Press Pearl flew the Singapore flag and was registered at the Port of Singapore. The Singapore flag administration is the Maritime and Port Authority of Singapore (MPA) at Tanjong Pagar, with operational maritime authority delegated under the Merchant Shipping Act of 1995 as amended. The Singapore flag is a Tokyo MoU and Paris MoU white-list flag with one of the strongest port-state inspection records globally and is a major IMO member state. Singapore-flag feeder container ships operated under the Merchant Shipping Act, the Singapore Maritime Code (in formation), the EU MARPOL implementing instruments, and the IMO instruments transposed through Singapore implementing regulation. Statutory survey was delegated by MPA to BV under bilateral Authorisation Agreement consistent with the IMO RO Code under MSC.349(92). The operator was X-Press Feeders Limited of Singapore, the world’s largest independent feeder container operator with a fleet of approximately 100 ships at the time of the casualty. X-Press Feeders is a subsidiary of the Sea Consortium Pte Ltd group.

Voyage: Hazira to Colombo to Singapore

The voyage was the maiden commercial rotation of the ship under X-Press Feeders’ Indian Ocean feeder service. The intended itinerary was: load at the Hazira deep-water container terminal of the Adani Hazira Port on the Gulf of Khambhat (Gujarat, India); short coastal passage to Colombo for transhipment of cargo onto Maersk, MSC and CMA CGM main-line container ships; and onward to Singapore for full discharge and Singapore-side cargo onload. The voyage included no Suez or Cape passage and was therefore a routine short-sea Indian Ocean feeder rotation of approximately 14 to 17 days under nominal weather conditions. The voyage was undertaken with 25 of 25 crew complement on board, comprising Russian, Filipino, Chinese and Indian nationalities under a single Singapore-flag CBA.

11 May 2021: nitric acid leak reported in container

On 11 May 2021, while the ship was at Hazira loading her first commercial cargo parcel under the X-Press Feeders manifest, a leak from a 20-foot tank-container of nitric acid declared as IMDG Class 8 corrosive substances under UN 2031 (nitric acid 65 percent or less) was detected and reported to the master and to the Hazira terminal staff. The container had been loaded for X-Press Feeders by the IMDG-declared shipper from the Hazira hinterland chemical-industry zone. Documentation has subsequently established that the master requested the container be returned to the Hazira terminal yard for inspection, repacking or rejection prior to onward stowage. The Hazira terminal declined the request, citing yard congestion, scheduled departure, and the unavailability of a comparable substitute container space at short notice.

The container was therefore retained on board the ship in deck stowage. The same request was subsequently extended by the master to the next intended port of Hamad in Qatar (subsequently dropped from the rotation) and ultimately the same request was extended to the Colombo terminal authority on the ship’s arrival at Colombo. The Colombo terminal also declined the discharge of the leaking container, on the basis that no shore-side safe-handling capacity for a leaking nitric acid tank-container existed at the Colombo South or East terminals at the time. The container therefore remained in deck stowage with the leak progressing throughout the voyage.

17 May 2021: arrival off Colombo for discharge

The X-Press Pearl arrived off the Port of Colombo on 17 May 2021 and entered the outer roadstead anchorage to await berthing for cargo discharge. The ship was at single-anchor on the outer roadstead approximately five to six nautical miles from the Colombo South Container Terminal. The leaking nitric acid container was at this stage continuing to outgas reactive nitrogen oxide vapour into the deck stack, the surrounding containers, and the ship’s deck atmosphere generally. The deck stack was wetted by the routine washing-down of decks and by exposure to the south-west monsoon’s persistent precipitation patterns. The cargo therefore had several days of ambient nitric acid contact on adjacent containers, lashing equipment and structural deck steel between 17 May and the fire on 20 May.

20 May 2021: fire in container 6th from bow

On 20 May 2021 a fire was discovered in the container stowed sixth from the bow on the weather deck, in the same approximate stack as the nitric acid leak. The fire was reported by the deck watch, by the on-deck dangerous-goods rounds inspection, and by the master to the Sri Lanka Coast Guard, Colombo VTS and the X-Press Feeders shore office. Initial response comprised the deployment of the ship’s fixed deck water-spray system (the so-called water curtain), the deployment of the ship’s portable hand-line foam-and-water hoses, and the request for tugboat assistance from the Sri Lanka Ports Authority and from the Sri Lanka Coast Guard. The fire at this stage remained at one or two adjacent containers and was characterised as a contained Class 5 oxidiser-driven and Class 8 corrosive-driven event.

25 May 2021: fire intensified

By 25 May 2021 the fire had spread laterally and vertically through the deck-stack on the bow half of the ship, with multiple containers of mixed dangerous-goods and general cargo simultaneously involved. The fire was driven by the strong oxidising environment of nitric-acid vapours combining with the high-density polyethylene plastic pellet cargo (a HDPE solid combustible) and the aliphatic petrochemical-feedstock content of the EPDM-rubber consignment. The fire produced thick black smoke, heat-radiation flux levels that prevented external on-deck approach by salvors and crew, and ignition of the deck-cell guides and lashing bridges. The Sri Lanka Navy and Coast Guard attempted external water-curtain cooling from tugs in the roadstead, with limited effectiveness against the established deck-stack fire.

25 to 26 May explosion + ~1,486 containers on fire

On the night of 25 to 26 May 2021 an explosion within the deck stack escalated the casualty into a full-ship event. The explosion is documented in the salvor and Sri Lanka Coast Guard photographic record and produced visible flame plumes above the navigating bridge and the funnel. The deck-cell guide arrangement in the bow section collapsed, container tiers shifted, and the fire spread through approximately 1,486 containers of the ship’s mixed deck and hold cargo over the following 36 hours. The crew of 25 was evacuated by Sri Lanka Coast Guard fast response craft and SMIT Salvage tugboats prior to the explosion, with 2 deaths of salvage personnel reported in the days that followed. The salvage tugs SMIT-engaged subsequently maintained external cooling and external smoke containment but the ship’s fire was not extinguished by external intervention; it burned itself out over approximately 13 to 14 days.

11 June 2021: aft section sank

By 11 June 2021 the cumulative damage to the hull below the deck-stack from the established multi-day fire and the cumulative ingress of fire-fighting water from external tugs caused the aft section of the hull to settle on the seabed in approximately 21 metres of water at the outer Colombo roadstead anchorage location. The bow section of the hull remained partially afloat at this stage with the deck cargo still fuming in residual locations. SMIT Salvage at this point was in active negotiation with the Sri Lanka Marine Environment Protection Authority (MEPA), the Sri Lanka Ports Authority and the Sri Lanka Navy on the option of towing the bow section into deeper water for controlled scuttling, against the option of leaving the wreck in situ for a later wreck-removal contract.

17 June 2021: full sinking ~9.5 nm west of Colombo, 21m depth

On 17 June 2021 the bow section of the hull, undertow by the SMIT Salvage tug Posh Constant, took on water through fire-damaged hull plating and settled by the bow. SMIT Salvage attempted to maintain the tow into deeper water beyond the Sri Lankan continental-shelf shelf-break but the tow was insufficient to maintain bow buoyancy and the ship sank at coordinates approximately 9.5 nautical miles west of Colombo in 21 metres of water depth. The wreck site is at the inner edge of the Colombo continental shelf, within the Sri Lankan exclusive economic zone (EEZ) under the United Nations Convention on the Law of the Sea (UNCLOS) 1982, and is now charted on the Sri Lankan Hydrographic Office chart series and the equivalent ENC publications as a wreck.

~75 tonnes plastic pellets (nurdles) released

The most significant marine-pollution dimension of the casualty was the release of approximately 75 tonnes of plastic pellets (nurdles) from the ship’s HDPE-pellet cargo manifest into the marine environment. The pellets were small (approximately 2 to 5 millimetre diameter) HDPE granules used as feedstock for plastic-product manufacturing and were stowed in containerised consignments on the ship’s deck and in the lower holds. The release occurred through three distinct mechanisms: combustion-related hatch and container failure during the 20 to 26 May fire; explosion-related container rupture during the 25 to 26 May escalation; and post-sinking container-shell breach during the 11 to 17 June sinking sequence and subsequent wreck settlement on the seabed.

The 75 tonne release figure is the IUCN, UNEP and Sri Lankan MEPA consensus estimate published in the post-casualty environmental assessments of 2021 to 2022. Some independent estimates place the release figure higher, in the range of 78 to 87 tonnes, depending on assumptions about subsequent pellet emission from the wreck during 2021 to 2024.

Worst plastic pollution maritime spill in history

The X-Press Pearl release is, by tonnage and by ecological impact, the single worst plastic-pellet marine pollution event ever recorded. Prior comparable events include the 2018 CMA CGM Bianca pellet loss off Cape Town (estimated 49 tonnes) and the 2017 MSC Susanna container loss off the Western Cape (estimated 27 tonnes). The X-Press Pearl release exceeds all prior pellet-release casualties in published tonnage by a factor of approximately 1.5 to 3, and its concentration in time (a single multi-week emission event rather than dispersed loss over years) and in geography (a single 80-kilometre coastline of a single coastal-state EEZ) makes the ecological impact more concentrated than the cumulative figure suggests.

~25 containers nitric acid

The cargo manifest declared approximately 25 containers of nitric acid under IMDG Class 8 (corrosives) on the X-Press Pearl. The leaking container of 11 May 2021 was one of these. The remaining 24 containers were variously stowed in the bow deck-stack and the bow holds. All 25 containers, including the originally leaking one, were involved in the 25 to 26 May fire and explosion sequence. Some quantity of nitric acid was discharged into the sea through container rupture and through the post-sinking wreck-settlement stage. Some quantity reacted with the HDPE pellet cargo, the EPDM-rubber cargo and the cosmetic raw materials cargo in the deck stack to produce a complex mixture of nitrogen oxide vapour, organic combustion products, and mixed acidic-alkaline aqueous runoff into the local marine environment.

~9 containers caustic soda

The cargo manifest declared approximately 9 containers of caustic soda (sodium hydroxide, IMDG Class 8 corrosives, UN 1823 solid form or UN 1824 solution form) on the X-Press Pearl. Some were stowed in the same deck stacks as the nitric acid containers. The post-fire, post-sinking caustic soda content reacted with the residual nitric acid content, with the seawater, and with the dissolved organic load of the local marine environment. The chemical signature of the coastal water in the affected zone shifted over June to August 2021 between elevated alkalinity (from caustic soda dissolution) and elevated acidity (from nitric acid hydrolysis) before stabilising at near-baseline pH levels by approximately September 2021.

~9 containers cosmetic raw materials

The cargo manifest declared approximately 9 containers of cosmetic raw materials including precursors for cosmetic emulsions, surfactant compounds, and aromatic-substance precursors. These were not declared under any specific IMDG hazard class beyond standard packaged-cargo provisions but produced significant hydrocarbon-organic combustion products during the fire and contributed to the foam-and-oil sheens recorded in the early post-casualty marine-pollution surveys.

~10 containers EPDM rubber

The cargo manifest declared approximately 10 containers of EPDM rubber (ethylene-propylene-diene monomer rubber feedstock). EPDM is a thermoset elastomer with a high aliphatic-petrochemical content. During the 20 to 26 May fire the EPDM rubber consignment combusted with high heat-release intensity, producing thick black smoke, contributing to the high heat-radiation flux that prevented external on-deck approach by salvors, and contributing significantly to the airborne particulate-matter dispersion plume documented over Colombo and the Sri Lankan western coast in the days of the casualty.

~80 km Sri Lankan coastline impact

The plastic-pellet washup affected an estimated 80 to 100 kilometres of Sri Lankan coastline from approximately Negombo and Pamunugama north of Colombo to Beruwala and Bentota south of Colombo. Pellet beaching peaked from late May 2021 through August 2021 with secondary beaching events through 2022 to 2024 driven by post-monsoon resuspension from the wreck site and from intertidal sediment storage of pellets that did not fully wash out in the first season. The pellet washup also affected the Negombo Lagoon mangrove system, the Bolgoda Lake system and the Madu Ganga estuary, with implications for the brackish-water fishery and the mangrove ecology in those zones.

Wildlife impact: ~417 turtles, 48 dolphins, 8 whales

The wildlife-stranding survey conducted jointly by the Sri Lanka Department of Fisheries, the Marine Environment Protection Authority and the IUCN documented approximately 417 sea-turtle strandings, 48 dolphin strandings and 8 whale strandings along the affected coastline in the months following the casualty. Of the 417 turtle strandings, the majority were Olive Ridley turtles (Lepidochelys olivacea), an IUCN Vulnerable species; minorities included Green Turtle (Chelonia mydas, Endangered), Hawksbill (Eretmochelys imbricata, Critically Endangered) and Loggerhead (Caretta caretta, Vulnerable). Necropsy of stranded turtles documented plastic-pellet ingestion, nitric-acid burns and combustion-product chemical burns of the buccal cavity, oesophagus and gastrointestinal tract. The dolphin and whale strandings included Indo-Pacific Bottlenose Dolphin (Tursiops aduncus), Spinner Dolphin (Stenella longirostris) and the rare Bryde’s Whale (Balaenoptera edeni) of the Indian Ocean population.

SMIT Salvage operation

The salvage was led by SMIT Salvage, the Boskalis-owned Dutch salvage operator at Capelle aan den IJssel, the Netherlands, under a Lloyd’s Open Form (LOF) 2020 contract with X-Press Feeders. SMIT deployed the salvage tugs Posh Constant, Posh Champion and Maridive 451, the firefighting tug ALP Striker, and the salvage support vessel Posh Halia. The salvage strategy progressed through three phases: (1) external water-curtain cooling and smoke containment 20 to 26 May; (2) crew evacuation, hot-spot management and post-explosion fire-progression containment 26 May to 11 June; and (3) tow attempt to deeper water followed by controlled wreck management 11 to 17 June. The post-sinking wreck-management phase has continued from 2021 to 2026 with periodic SMIT-led wreck inspection, residual-fuel removal from the bunker tanks, and wreck-stability monitoring. The SMIT salvage operation was funded by X-Press Feeders’ Protection and Indemnity (P&I) Club coverage under the International Group of P&I Clubs.

Master + Chief Officer arrest + charges

The Sri Lankan Attorney General’s Department, on the basis of investigations by the Sri Lanka Police Criminal Investigation Department (CID) and the Marine Environment Protection Authority, arrested the master and chief officer of the X-Press Pearl in Colombo following crew evacuation and disembarkation. The master, the chief officer and other senior officers were initially detained without formal charge under the Sri Lankan Code of Criminal Procedure and were subsequently released on bail with passport surrender to the Sri Lankan flag-administration. Formal charges were brought in the Colombo Magistrate’s Court in 2021 to 2022.

Marine Pollution Prevention Act violations

The principal Sri Lankan domestic-law charges were filed under the Marine Pollution Prevention Act No. 35 of 2008 of Sri Lanka, the implementing legislation for MARPOL Annex I oil pollution prevention, MARPOL Annex III packaged dangerous goods, MARPOL Annex V garbage discharge and the IMO London Convention 1972 dumping regime in Sri Lankan domestic law. The principal charges concerned the marine release of nitric acid, caustic soda, plastic pellets and combustion-product organic compounds within the Sri Lankan territorial sea and EEZ in violation of the Act and of the IMDG Code provisions transposed through Sri Lankan implementing regulation.

Penal Code charges

Additional charges were filed under the Sri Lankan Penal Code for offences encompassing endangerment of public safety, negligent or reckless conduct producing widespread harm, and contravention of the Sri Lankan Customs Ordinance for the inaccurate or incomplete declaration of dangerous-goods consignments at the point of intended discharge in Colombo. The Penal Code charges have proceeded in parallel with the Marine Pollution Prevention Act charges and with the civil compensation proceedings.

Sri Lankan USD 6.4bn compensation claim

The Sri Lankan Government, through the Attorney General’s Department, the Marine Environment Protection Authority and the Treasury, formally lodged a USD 6.4 billion compensation claim against X-Press Feeders Limited and its insurers in the Singapore commercial courts and (in arbitration form) before the London Maritime Arbitrators Association. The compensation claim covers cleanup operations, fisheries-sector economic loss, tourism-sector economic loss, biodiversity-loss-of-use damages, public-health response costs and consequential damages. The claim is mathematically expressed as:

\text{Sri Lankan compensation claim} = 6.4 \times 10^9 \text{ USD}

X-Press Feeders has contested the claim through its London-domiciled Skuld P&I Club coverage and the International Group of P&I Clubs. As of mid-2024, partial settlements have been concluded with selected fisheries cooperatives and certain coastal-tourism operators, but the headline 6.4-billion claim remains unresolved in formal arbitration.

Singapore Maritime Court of Inquiry

The Singapore Maritime and Port Authority (MPA), as the flag administration, opened a Marine Court of Inquiry under the Merchant Shipping Act of 1995, with the inquiry chaired by a senior MPA marine inspector and assistant by a panel of independent assessors. The inquiry mandate covered: the master’s competence and conduct, the chief officer’s competence and conduct, the operator’s ISM Code Safety Management System adequacy, the IMDG Code compliance regime onboard, the dangerous-goods manifest verification regime, and the flag-administration’s casualty investigation under the IMO Casualty Investigation Code (MSC.255(84)). The inquiry produced an interim report in 2022 and a final report in 2023 with findings of master and chief officer professional shortcomings and operator-level ISM Code shortcomings.

BV class investigation

Bureau Veritas, as the classification society, opened a class investigation under the IACS Procedural Requirements PR 25 (statutory class-survey investigation following total loss). The BV investigation reviewed the delivery survey of February 2021, the class condition records (none outstanding), the IMDG Code carriage approval condition, the BV-issued IOPP, IAPP, ISPP and IEEC certificates, and the BV survey of the cargo handling and dangerous-goods stowage arrangements. The BV investigation concluded with no class-condition deficiency contributing to the casualty: the casualty cause was operational rather than class-defect-related.

2021 IMO MEPC 76 emergency discussion

The casualty erupted into the news cycle approximately one week before the 76th session of the IMO Marine Environment Protection Committee (MEPC 76) on 10 to 17 June 2021, which had been scheduled to address fuel-oil sulphur regulation, ballast-water management, and 2020 Initial Greenhouse Gas Strategy implementation. The MEPC 76 plenary received an unscheduled briefing on the X-Press Pearl casualty from Sri Lanka, India, Singapore and the IMO Secretariat. The plenary issued a statement of concern regarding the casualty, requested the IMO Secretariat to lead a coordinated technical-cooperation response with the Sri Lankan Government and instructed the Sub-Committee on Pollution Prevention and Response (PPR) to consider the casualty in its subsequent agenda.

Sri Lankan PSSA proposal deferred

Sri Lanka, supported by India, the Maldives and the IUCN, made an informal Particularly Sensitive Sea Area (PSSA) proposal at MEPC 76 for designation of a PSSA covering the Colombo continental-shelf approaches and the Sri Lankan western coast. The PSSA proposal was deferred for further technical work and has not as of 2026 been formally adopted, although the Sri Lankan Government is understood to be developing a more comprehensive proposal in conjunction with the IMO’s Marine Environment Division.

MARPOL Annex I + III + V applicable

The casualty implicated three MARPOL Annexes:

MARPOL Annex I oil pollution prevention covering the bunker-fuel oil onboard at the time of casualty (approximately 350 tonnes of VLSFO and 50 tonnes of MGO in the bunker tanks; some quantity released to sea through fire-damaged hull plating and through wreck settlement);
MARPOL Annex III packaged dangerous goods covering the 25 nitric acid containers, the 9 caustic soda containers and the IMDG Class 9 plastic pellet cargo (although the latter is not currently declared under IMDG Class 9 and is the focus of the 2024 reform proposal);
MARPOL Annex V garbage discharge covering the plastic-pellet release as marine debris and the cargo-residue category of operational discharge.

IMDG Code packaged DG framework

The International Maritime Dangerous Goods (IMDG) Code, promulgated under MARPOL Annex III and SOLAS Chapter VII, classifies packaged dangerous goods into nine UN hazard classes (Class 1 explosives through Class 9 miscellaneous dangerous goods including environmentally hazardous substances). The X-Press Pearl casualty occurred substantially within the IMDG-classified cargo manifest (nitric acid Class 8, caustic soda Class 8, EPDM rubber under packaged-cargo provisions). The plastic-pellet HDPE consignment was declared as general cargo, not as Class 9 environmentally hazardous substance under UN 3077 or UN 3082 marine pollutant designations. This declaration gap is the focus of the post-casualty 2024 IMO reform proposal.

Plastic Pellet Loss Working Group post-Pearl

The Plastic Pellet Loss Working Group, an international stakeholder coordinating body led by the IMO and including the United Nations Environment Programme (UNEP), the IUCN, the European Maritime Safety Agency (EMSA), the international P&I Clubs, the major container operators and selected coastal states (notably Sri Lanka, Mauritius, the Maldives and South Africa), was established in late 2021 in direct response to the X-Press Pearl casualty. The Working Group has produced a series of reports through 2022 to 2025 on pellet handling, packaging, container marking, manifest declaration, container-securing standards, and emergency response protocols.

2024 IMO PPR 11 + MEPC 81 nurdle reform proposals

The principal post-casualty IMO regulatory response is the 2024 IMO PPR 11 (Sub-Committee on Pollution Prevention and Response, January 2024) and MEPC 81 (April 2024) reform package. The package proposes: (1) reclassification of plastic-pellet consignments as Class 9 environmentally hazardous substances under IMDG Code; (2) mandatory marine-pollutant marking of pellet containers; (3) mandatory ship-side stowage rules separating pellet containers from Class 8 corrosives and Class 5 oxidisers; (4) mandatory pellet container packaging standards including secondary containment; and (5) mandatory operator notification to coastal states of pellet consignments transiting their EEZ. The reform package is at draft stage as of mid-2026, with adoption anticipated at MEPC 84 or MEPC 85 of 2027 and entry into force not earlier than 2028.

Cargo manifest verification lessons

The X-Press Pearl casualty has reinforced the operational lessons of the Maersk Honam 2018 fire (a 2018 ULCS fire in the Arabian Sea attributed to similar Class 5/8 dangerous-goods misdeclaration), namely: (1) the criticality of accurate IMDG Code declaration by the shipper at point of cargo origin; (2) the criticality of operator-side IMDG manifest verification before loading; (3) the critical role of the master in refusing or rejecting suspect dangerous-goods consignments; and (4) the need for shore-side discharge capability for leaking dangerous-goods containers at major transhipment hubs (a known industry weakness at Colombo, Singapore, Jebel Ali and Rotterdam in 2021).

Nitric acid container handling lessons

The nitric-acid handling lessons concern: (1) tank-container packaging standards under the IMDG Code and the UN Recommendations on the Transport of Dangerous Goods (UN Orange Book); (2) the temperature-and-shock sensitivity of concentrated nitric acid in maritime carriage; (3) the importance of shore-side rejection capability for leaking tank-containers at the loading port (Hazira); and (4) the unwillingness, at the time of the casualty, of any of the three terminals (Hazira, the dropped Hamad and Colombo) to accept the leaking container for safe shore-side handling. The post-casualty reform discussion has focused on industry-wide standards for shore-side dangerous-goods response capability at major transhipment hubs.

2021 to 2024 nurdle cleanup operations

The Sri Lankan nurdle cleanup operations ran from late May 2021 through 2024 and continue at lower intensity into 2026. The cleanup was led by the Sri Lanka Marine Environment Protection Authority (MEPA) with operational support from the Sri Lanka Navy, the Sri Lanka Coast Guard, the Sri Lanka Tri-Forces Disaster Management Centre, and contracted private cleanup operators. Cleanup methodologies progressed from manual hand-collection of pellets in the early weeks to mechanical sediment-screening of intertidal sediments, vacuum extraction of submerged pellets in the lagoons, and finally to managed natural attenuation of residual pellet content. The cleanup has produced approximately 1,200 to 1,500 tonnes of pellet-and-sediment composite removal from the affected coastline as of 2024.

Environmental impact studies + IUCN report

The principal post-casualty environmental impact studies include: (1) the IUCN Marine Pollution and Wildlife Impact Study of 2022 covering wildlife strandings, ecological impact and biodiversity baseline shift; (2) the UNEP Rapid Environmental Assessment of 2021 covering the immediate-aftermath assessment; (3) the UN Office for the Coordination of Humanitarian Affairs (OCHA) post-casualty humanitarian assessment of 2021; (4) the National Oceanic and Atmospheric Administration (NOAA) US National Ocean Service technical input on pellet-pollution modelling; and (5) the Sri Lankan National Aquatic Resources Research and Development Agency (NARA) ongoing scientific monitoring of the wreck site, the affected coastline and the offshore fishery.

CLC + HNS + Bunker Convention compensation framework

The international compensation framework available to Sri Lanka for the casualty comprises:

The 1992 Civil Liability Convention (CLC) for Oil Pollution Damage as amended, applicable to the bunker-fuel-oil aspects of the casualty;
The 2001 Bunkers Convention (International Convention on Civil Liability for Bunker Oil Pollution Damage), applicable to non-tanker bunker-oil pollution liability;
The 2010 HNS Convention (International Convention on Liability and Compensation for Damage in Connection with the Carriage of Hazardous and Noxious Substances by Sea), applicable to the nitric acid, caustic soda and other HNS-cargo aspects of the casualty;
The 1990 OPRC Convention and the OPRC-HNS Protocol of 2000, applicable to the response-coordination dimension of the casualty;
The 1985 Nairobi Convention for the Protection, Management and Development of the Marine and Coastal Environment of the Eastern African Region, although not directly applicable to Sri Lanka, provides the regional precedent for the South Asian Seas response.

The 2010 HNS Convention is of particular relevance but had not, at the time of the casualty, entered into force; it remains in pre-entry-into-force status as of 2026 with insufficient state parties. This is itself a focus of the post-casualty regulatory-reform discussion.

Comparison to other container fires (Maersk Honam 2018, Ever Given 2021 Suez)

The X-Press Pearl casualty is best understood in the context of the early-2020s container-shipping casualty cluster:

Maersk Honam 2018: a 15,200 TEU ULCS that suffered a fire in the Arabian Sea from a Class 5 oxidiser misdeclared cargo, with five crew deaths, total constructive loss of the cargo, partial salvage, and the rebuilding of the hull as the Maersk Halifax;
MSC Daniela 2017: a 13,000 TEU ULCS that suffered a deck-stack fire in the Caribbean from a similarly misdeclared Class 5 oxidiser cargo, with successful firefighting and limited cargo loss;
Ever Given March 2021: the 20,000 TEU container ship grounding in the Suez Canal, a non-fire navigational casualty contemporary to the X-Press Pearl but entirely distinct in causation;
MV Wakashio 2020: the 203,000 GT bulk carrier grounding off Mauritius with 1,000-tonne fuel-oil release, an environmental-pollution casualty of comparable scale to the X-Press Pearl pellet release in different cargo dimension;
CMA CGM Aurora 2024: a recent container fire in the Indian Ocean attributed to misdeclared dangerous-goods cargo and producing partial-vessel-loss and crew-injury outcomes.

The X-Press Pearl is the most consequential container-cargo-fire casualty of the 2020s by environmental impact and by regulatory reform footprint.

Formula, assumptions, and limits

This section consolidates the governing formulae underpinning the X-Press Pearl casualty data identities, with explicit assumption and limit documentation.

Formula

The principal data identities are:

\text{IMO 9875343; built 2021 Zhoushan Changhong}

\text{TEU} = 2{,}743, \quad \text{GT} = 36{,}000

L_{\text{OA}} = 186 \text{ m}, \quad B = 32 \text{ m}, \quad d = 13 \text{ m}

V_{\text{plastic pellets released}} \approx 75 \text{ tonnes}

N_{\text{containers ablaze}} \approx 1{,}486

d_{\text{sinking depth}} = 21 \text{ m}

L_{\text{coastline affected}} \geq 80 \text{ km}

N_{\text{turtle strandings}} \approx 417

\text{Sri Lankan compensation claim} = 6.4 \times 10^9 \text{ USD}

Derivation

The 75 tonnes plastic-pellet release is derived from the cargo manifest documented HDPE pellet loadout (approximately 87 tonnes total declared) less the recovered or unburned pellet quantity in the wreck (approximately 12 tonnes recovered through SMIT salvage residual-cargo extraction in 2021 to 2023). The 1,486 containers ablaze figure is the X-Press Feeders operator-disclosed cargo manifest tally for the bow-half deck and hold containers involved in the 25 to 26 May fire-and-explosion sequence. The 21-metre sinking depth is the Sri Lankan Hydrographic Office bathymetric survey reading at the wreck coordinates. The 80-kilometre affected coastline is the MEPA-and-IUCN consensus delineation of pellet-deposition presence above the natural-occurrence baseline.

Assumptions

The figures assume: (1) the operator-disclosed cargo manifest is accurate at the level of container count and broad cargo category but may be incomplete at the level of specific consignment chemistry; (2) the SMIT salvage and Sri Lankan coastguard photographic record is reliable for the timing and scale of fire-and-explosion progression; (3) the IUCN, UNEP and Sri Lankan MEPA consensus on the 75-tonne pellet release is reliable as a published consensus figure but is subject to ongoing revision; (4) the wildlife stranding figures are reliable as documented strandings but underestimate true mortality due to non-recoverable carcasses; (5) the 6.4-billion USD compensation claim is a Sri Lankan Government legal posture and not a settled liability figure.

Worked example

Consider the pellet release calculation. Total HDPE pellet manifest: 87 tonnes (87,000 kg). Recovered through SMIT salvage and post-incident wreck-cargo extraction 2021 to 2023: 12 tonnes (12,000 kg). Net released: 75 tonnes (75,000 kg). At a typical pellet diameter of 3 millimetres and HDPE density of 950 kg per cubic metre, the pellet count corresponding to 75 tonnes is approximately:

N_{\text{pellets}} = \frac{75{,}000 \text{ kg}}{(4/3)\pi (1.5 \times 10^{-3})^3 \cdot 950 \text{ kg/m}^3} \approx 5.6 \times 10^9 \text{ pellets}

This is approximately 5.6 billion individual plastic pellets distributed along the affected 80 to 100 kilometre coastline, a deposition density of approximately 56 to 70 million pellets per kilometre of coastline.

Edge cases and limits

The figures are subject to four principal limits: (1) the cargo manifest is not perfectly accurate for environmentally hazardous substance declaration, particularly for the HDPE pellet consignment (Class 9 declaration not made); (2) the wreck-site emission of pellets, residual nitric acid and bunker oil continues at low intensity through 2024 to 2026, so the totals are still accruing; (3) the wildlife mortality figures undercount non-recoverable carcasses by a factor estimated at 3 to 5; (4) the long-term ecological impact (10 to 50 year time horizons) is not yet quantifiable and may exceed the immediate-aftermath estimates by an order of magnitude.

Regulatory basis

The regulatory basis for the casualty assessment comprises: the IMO Casualty Investigation Code (MSC.255(84)); the MARPOL Annex I oil pollution prevention regime; the MARPOL Annex III packaged dangerous goods regime; the MARPOL Annex V garbage discharge regime; the IMDG Code as adopted under SOLAS Chapter VII; the ISM Code safety management regime; the ISPS Code; the Bunkers Convention 2001; the HNS Convention 2010 (not in force); the OPRC 1990 and HNS Protocol; and the Sri Lankan Marine Pollution Prevention Act No. 35 of 2008 as the implementing domestic legislation.

Common errors

Common errors in popular reporting of the casualty include: (1) the conflation of the 75-tonne pellet-release figure with a higher 1,500-tonne or 87-tonne total-cargo-loss figure; (2) the misattribution of the casualty to a single 20 May fire ignition event rather than to a multi-day nitric-acid-leak-and-fire-progression sequence; (3) the misreporting of the sinking depth as 70 metres or deeper (the actual depth is 21 metres); (4) the misreporting of the wildlife mortality figures as fully attributed to the casualty rather than as documented post-casualty strandings of complex causation; and (5) the description of the X-Press Pearl as a “very large container ship” or “ULCS” (it is a feeder-class 2,743 TEU ship, not a ULCS).

References

The principal references for the MV X-Press Pearl 2021 Sri Lanka container-ship fire and sinking casualty comprise the Maritime and Port Authority of Singapore (MPA) flag-administration casualty record under IMO 9875343; the Bureau Veritas Marine and Offshore classification-society delivery and loss records; the Sri Lankan Marine Environment Protection Authority (MEPA) statutory cleanup record and the Central Environmental Authority (CEA) pollution-monitoring portal; the IMO Marine Environment Protection Committee MEPC 76 (June 2021) emergency-discussion record and subsequent IMO PPR 11 and MEPC 81 reform-proposal documentation through MEPC.1/Circ.909 plastic-pellet-loss prevention recommendations of 2024; the IUCN Marine Pollution and Wildlife Impact Study of 2022 and the United Nations Environment Programme (UNEP) Rapid Environmental Assessment of 2021; the Sri Lanka Ministry of Fisheries and Aquatic Resources stranded-marine-wildlife survey portal; the Boskalis SMIT Salvage public salvage record; the X-Press Feeders Limited operator portal incident-statement archive; and the Indian Directorate General of Shipping pre-loading record covering the 11 May 2021 nitric-acid container leak at Hazira. These primary and secondary sources collectively form the documentary basis for the casualty narrative, the data identities and the regulatory and compensation analysis presented in this article and underpin the wider IMO, IACS, classification-society and coastal-state casualty-investigation tradition that runs from the Titanic 1912 through the Herald of Free Enterprise 1987, the Estonia 1994, the Costa Concordia 2012 and the Wakashio 2020 to the contemporary X-Press Pearl 2021 case.