Mercury

The Minamata Convention: The Treaty That Defines Mercury's Endgame

1.1 Treaty architecture and objective

The Minamata Convention on Mercury takes its name from Minamata, Japan, the city where industrial mercury discharge into Minamata Bay caused decades of severe mercury poisoning in local residents. The treaty's objective, stated plainly in Article 1, is “to protect the human health and the environment from anthropogenic emissions and releases of mercury and mercury compounds” (Minamata Convention text and booklet, UNEP). It covers the entire mercury lifecycle — primary mining, trade, mercury-added products, manufacturing processes, artisanal gold mining, emissions, storage, and waste disposal.

1.2 COP-5 (2023) and COP-6 (2025): tightening the phase-out schedule

The treaty's governing body, the Conference of the Parties (COP), has met six times and used each meeting to tighten the phase-out schedule. COP-5, held 30 October–3 November 2023 in Geneva, set 2025 as the phase-out date for mercury-cell chlor-alkali production and several mercury-added products, with those amendments entering into force on 25 April 2025 (UN Secretariat communication, 22 May 2025). COP-5 also amended Annex A to add further phase-out dates for specific fluorescent lamp categories (IISD Earth Negotiations Bulletin, COP-5 summary). COP-6, held 3–7 November 2025 in Geneva, adopted 22 decisions, most notably a global phase-out date of 2034 for dental amalgam, alongside decisions on financial mechanism replenishment and effectiveness evaluation (IADR/FDI press release, 7 Nov 2025). A parallel COP-6 push to set a firm phase-out date for mercury use in vinyl chloride monomer (VCM) production was deferred to COP-7 after opposition from China, the process's dominant user (Zero Mercury Working Group, COP-6 Statement on VCM, 3 Nov 2025).

1.3 Article 3: no new primary mining, mandatory wind-down

The Convention's core supply-side provisions are structural: Article 3 bars any Party from starting new primary mercury mining and limits mining already underway at treaty entry to a 15-year window, after which the mercury produced may be used only for allowed purposes or disposed of — not recycled or resold (Convention text and annexes). Article 3(6) also prohibits mercury exports except to a consenting Party for an allowed use or for environmentally sound interim storage, effectively making mercury one of the only industrial metals for which international trade itself is presumptively banned rather than merely taxed or licensed.

1.4 Effectiveness Evaluation and the Global Mercury Assessment

Article 22 requires the Convention to periodically evaluate its own effectiveness using comparable monitoring data on mercury levels in the environment and in vulnerable populations. The Secretariat's effectiveness evaluation work draws heavily on the UNEP Global Mercury Assessment series — the 2018 edition remains the most recent full global emissions inventory cited by both UNEP and USGS, with a refreshed assessment anticipated by the Secretariat but not yet finalized as of mid-2026 (USGS MCS 2026, citing UNEP Global Mercury Assessment). National action plans and implementation reports, due periodically under Article 21, feed this evaluation cycle and are the primary mechanism by which the Secretariat tracks whether COP-mandated phase-out dates are being met on the ground.

Why it matters: unlike critical minerals such as gallium or antimony, where national governments compete to secure supply, mercury policy runs in the opposite direction — every major economy is legally committed to eliminating primary production, restricting trade, and phasing out use. The Convention converts mercury from a commodity market into a managed wind-down, with COP decisions functioning as binding amendments once they enter into force for ratifying Parties.

Global Supply Collapse: From Cinnabar Mines to a Recycling-Dependent Market

2.1 Mine production by country, 2024–2025

Source: USGS MCS 2026, mercury chapter. Spain's centuries-old Almadén mine, historically the world's largest cinnabar (mercury sulfide) deposit, ceased mining in 2003; world estimated mercury resources remain around 600,000 tonnes, concentrated in China, Kyrgyzstan, Mexico, Peru, Russia, Slovenia, Spain, and Ukraine, but Article 3 of the Minamata Convention forecloses new primary mining in any ratifying Party. USGS states plainly that quantitative reserve estimates for mercury “were not available,” with China, Kyrgyzstan, and Peru holding the largest reserves.

2.2 Kyrgyzstan's Khaidarkan mine: the last exporting primary mercury mine

The Khaidarkan Mercury Joint Stock Company in southern Kyrgyzstan is internationally recognized as “the last primary mercury mine known to export mercury to the global market-place” — a status the United Nations formally flagged more than a decade ago while urging the Kyrgyz government toward transition rather than continued production (United Nations statement on the Khaidarkan primary mercury mine). The mine has historically provided roughly 600 jobs in an economically depressed region, creating the central policy dilemma UNEP and UNDP have worked to resolve: preserving local livelihoods while eliminating a legally disfavored, treaty-incompatible production source (UNEP-UNITAR Mercury Platform, Khaidarkan mercury overview).

The Global Environment Facility has directly funded “assistance to enable closure of the Khaidarkan mine in the Kyrgyz Republic” as a named priority within its broader mercury portfolio, which had approved US$8.3 million across 12 mercury-related projects (GEF Mercury Factsheet). Complementary UNDP-GEF technical assistance in Kyrgyzstan has focused on downstream mercury-waste management — for example, a 2016 agreement under which the Ministry of Health sent mercury-containing medical thermometers collected from pilot healthcare facilities to the Khaidarkan integrated plant for controlled thermal disposal and mercury recovery, illustrating how the mine itself has been repurposed toward waste processing even as new primary output continues (Donors.kg / UNDP-GEF Kyrgyzstan project report, 2015–16). USGS's own country table continues to record Kyrgyzstan at a modest 5 tonnes of mine production in both 2024 and 2025 — far below China's 200 tonnes but persistent nonetheless (USGS MCS 2026).

2.3 Legal supply sources after Article 3: byproduct, decommissioning, recycling

With new primary mining essentially closed off by treaty, the market has restructured around three legal supply sources: byproduct recovery from gold-silver ore processing (USGS notes mercury was recovered as a byproduct at several Nevada mines in 2025, though production data were not separately reported); decommissioning of mercury-cell chlor-alkali plants, which releases large volumes of elemental mercury as those plants convert to membrane-cell technology; and secondary recovery (recycling) from batteries, fluorescent lamps, dental amalgam, thermostats, and other mercury-added products (USGS MCS 2026).

USGS reports that in 2025, eight facilities operated by six companies in the United States accounted for most domestic secondary mercury production, recovering mercury from automobile convenience switches, barometers, compact and traditional fluorescent bulbs, computers, dental amalgam, medical devices, and thermostats via retorting. The ongoing LED lighting transition is accelerating this recycling stream, as fluorescent lamp retirement releases more mercury for recovery even as new mercury-containing lamp manufacturing declines (USGS MCS 2026). USGS explicitly flags that the ultimate closure of the world's remaining mercury-cell chlor-alkali plants “may release a large quantity of mercury to the global market for recycling, sale, or, owing to export bans in Europe and the United States, long-term storage.”

2.4 US domestic production and consumption trend

The EPA's 2023 triennial mercury report — the closest available proxy for domestic secondary production, since the US produces no primary mercury — recorded domestic byproduct and secondary elemental mercury production of 103 tons in 2021, up from 45 tons in 2018, while mercury stored by manufacturers or producers rose to 182 tons in 2021 from 82 tons in 2018. Reported domestic consumption of mercury and mercury in products was 13 tons in 2021, down from 16 tons in 2018 (USGS MCS 2026, citing EPA 2023 Triennial Report). A separate, much larger volume — about 163 tons — is used domestically in closed-loop manufacturing processes such as catalysts and the chlor-alkali cathode, of which “almost all” is reused within the process rather than consumed (USGS MCS 2026).

Why it matters: mercury is the rare commodity where the regulatory phase-out is the supply story. There is no shortage narrative and no price-spike-driven scramble for new mines — instead, the entire policy apparatus (Minamata Article 3, EU Regulation 2017/852, the U.S. Mercury Export Ban Act) is designed to prevent the growing pool of decommissioning-and-recycling mercury from re-entering active commercial use, funneling it instead toward permanent storage.

Artisanal Gold Mining: The Last Major Mercury Demand Source

3.1 How mercury amalgamation works and why it is hard to displace

Miners use mercury to form an amalgam with gold particles in crushed ore, then burn off the mercury — often in open air with no capture equipment — to recover the gold, releasing mercury vapor directly into the atmosphere and local water systems. The Minamata Convention addresses this explicitly in Article 7 and Annex C, requiring Parties with ASGM activity to develop national action plans to reduce, and where feasible eliminate, mercury use (Minamata Convention Secretariat, ASGM Mercury Monitoring Technical Document). Non-mercury alternatives — gravity concentration, borax-assisted smelting, and cyanide leaching under controlled conditions — exist and are technically proven, but require capital, training, and formalization of a sector that is overwhelmingly informal, cash-based, and geographically dispersed, which is why mercury use has persisted despite two decades of international attention.

3.2 planetGOLD and the GEF financial mechanism

The UN Environment Programme's planetGOLD programme, implemented jointly by UNEP and UNDP and funded by the Global Environment Facility under the Convention's Article 13 financial mechanism, is the primary multilateral vehicle for ASGM mercury reduction. As of a February 2023 UN News report, planetGOLD had already cut mercury use by nearly 370 tonnes across nine countries and was scaling to 15 additional countries with a goal of eliminating 512 tonnes of mercury use, while also targeting improvements across more than 1.2 million hectares of land and benefits for 370,000 people (UN News, 16 Feb 2023). The same report cautions that “enforcement is not always consistent” across jurisdictions even where governments have committed to Minamata implementation.

3.3 National action plans and the 2032 ASGM target

Independent monitoring groups continue to document large mercury flows into ASGM despite the treaty framework. IPEN's 2025 country status reports on the ASGM sector, including one on Kenya, reiterate the Convention's stated targets to end the global mercury trade and eliminate mercury use in ASGM by 2032 (IPEN, Mercury Trade Kenya Country Status Report, 2025). Separately, the Environmental Investigation Agency's July 2025 report on U.S. mercury smuggling found that mercury — some of it laundered through recycling-exemption loopholes — continues to reach ASGM operators despite formal import/export prohibitions (Environmental Investigation Agency, Jul 2025).

3.4 Formalization and non-mercury method adoption

The policy consensus among the Minamata Secretariat, planetGOLD, and NGOs such as IPEN is that mercury elimination in ASGM depends less on new technology than on formalizing the sector: legal mining permits, access to finance, gold-buying schemes that reward mercury-free output, and enforcement capacity in remote mining regions. Borax-assisted smelting (used widely in the Philippines and parts of Africa) and direct-smelting methods that avoid mercury entirely are the most commonly cited technical substitutes, alongside gravity-concentration circuits that reduce but do not eliminate mercury dependency (Minamata Convention Secretariat, ASGM Mercury Monitoring Technical Document).

Why it matters: ASGM is the segment where Minamata's legal architecture and on-the-ground reality diverge most sharply. Formal supply (mining, trade, chlor-alkali) is contracting under binding treaty deadlines, but informal, largely unmonitored ASGM demand for mercury — concentrated in Sub-Saharan Africa, Southeast Asia, and the Amazon basin — remains the dominant real-world use of mercury on Earth, and enforcement gaps mean legally banned mercury still finds its way into the sector.

EU and US Export Bans: Locking Mercury Out of the Market by Statute

4.1 EU Regulation 2017/852 and the 2024 amendment (Regulation 2024/1849)

Regulation (EU) 2017/852, adopted 17 May 2017 and applying from 1 January 2018, repealed the EU's earlier mercury export ban under Regulation (EC) No 1102/2008 and rebuilt it into a comprehensive lifecycle regime. Article 3(1) states plainly: “the export of mercury shall be prohibited.” Article 3(2) extends the ban to a defined list of mercury compounds and mixtures (mercury(I) chloride, mercury(II) oxide, cinnabar ore, and mercury sulfide from 1 January 2018; mercury(II) sulphate and mercury(II) nitrate from 1 January 2020). Article 4(3) separately and explicitly prohibits “the import of mercury for use in artisanal and small-scale gold mining and processing” (EU Regulation 2017/852, Articles 3–4).

The regulation was substantially amended by Regulation (EU) 2024/1849, published 10 July 2024: dental amalgam use for the general population banned from 1 January 2025 (with an 18-month socioeconomic derogation available to some member states), export banned from 1 January 2025, and manufacturing/import into the EU banned from 1 July 2026. The same amendment addresses mercury-added cosmetics, tightening the existing EU Cosmetics Regulation interface with the mercury framework so that skin-lightening creams and soaps containing mercury face parallel phase-out treatment from 2025 (European Parliament Legislative Train, Revision of the Mercury Regulation). A further Commission Delegated Regulation dated 17 December 2025 added mercury-added products to the export/import/manufacturing prohibition list with a phase-out date of 31 December 2025 (European Commission Delegated Regulation C(2025) 8844, 17 Dec 2025).

4.2 US Mercury Export Ban Act (MEBA) 2008 and DOE storage designation

The Mercury Export Ban Act of 2008 (Public Law 110-414), as amended by the 2016 Frank R. Lautenberg Chemical Safety for the 21st Century Act, prohibits the export of elemental mercury from the United States, with certain essential-use exemptions, effective 1 January 2013. Effective 1 January 2020, the export ban was extended to five additional mercury compounds. MEBA also directs the U.S. Department of Energy to designate a facility for the long-term management and storage of domestically generated elemental mercury (Federal Register, Record of Decision, 2 Dec 2024; USGS MCS 2026). Before the ban, USGS notes that “until December 31, 2012, domestic- and foreign-sourced mercury was refined and then exported for global use, primarily for small-scale gold mining in many parts of the world” — underscoring that the US itself was historically a mercury source feeding the ASGM sector it now funds programmes to demercurize.

On 21 November 2024, the DOE awarded a five-year contract to Waste Control Specialists (WCS) in Texas to construct and operate a long-term storage facility with capacity for as much as 7,000 tons of elemental mercury, fulfilling the MEBA storage-designation mandate more than a decade after the export ban took effect (Energy.gov, DOE announcement, 21 Nov 2024). Until that facility opens, USGS reports that eight facilities operated by six companies are authorized by DOE to temporarily store mercury (USGS MCS 2026). Notably, this DOE-designated storage program is distinct from, but analogous in purpose to, the Waste Isolation Pilot Plant (WIPP) model used for other hazardous material streams — both reflect a policy choice to permanently sequester a substance rather than allow re-entry into commerce.

4.3 Sweden's early precedent and the Basel Convention overlay

Sweden banned mercury use, export, and import domestically starting in 2009, ahead of both the EU regulation and the Minamata Convention itself, making it one of the first countries globally to adopt a comprehensive national mercury ban and an early template for the EU's later lifecycle approach (Zero Mercury Working Group, EU Mercury Policy overview). The Basel Convention on the Control of Transboundary Movements of Hazardous Wastes provides the complementary global waste-trade layer: its technical guidelines classify excess mercury from decommissioned chlor-alkali facilities and other mercury-containing waste streams as hazardous waste subject to Basel's prior-informed-consent transboundary movement controls, with the Minamata Secretariat and Basel bodies coordinating to avoid gaps between the two regimes (Basel Convention Technical Guidelines on mercury wastes, Minamata Secretariat reference document). Zero Mercury Working Group has separately pressed for the two treaty regimes to jointly ensure “sequestered mercury is not reintroduced into global commerce” (Zero Mercury Working Group, Mercury Waste and the Basel Convention).

Why it matters: the EU and US export bans, layered on top of the Minamata Convention's own Article 3 trade restrictions and the Basel Convention's waste-movement controls, mean that mercury freed up by chlor-alkali plant closures or product recycling in the two largest historical mercury-consuming blocs cannot legally re-enter global commerce. That mercury must instead go into designated storage — the WCS Texas facility in the U.S., and equivalent solidification-and-disposal requirements under Article 11 of the EU regulation — permanently removing volumes that would once have been resold.

Historical vs. Current Use: Mercury's Applications Have Nearly All Been Substituted

Source: USGS MCS 2026, mercury chapter.

5.1 Chlor-alkali production: mercury cells phased out in Europe and the US

Mercury-cell chlor-alkali plants, which use liquid mercury as an electrode to make chlorine and caustic soda, have been replaced across the OECD by membrane-cell and diaphragm-cell technology that requires no mercury at all. In Europe, Euro Chlor members voluntarily committed in 1999/2001 to convert all mercury-cell capacity to membrane technology by 2020, and the Industrial Emissions Directive's Best Available Techniques conclusions made mercury-cell cessation legally binding by 11 December 2017 (Euro Chlor, Mercury topic page). The OSPAR Commission confirmed in a December 2020 announcement that “all mercury cell chlor-alkali plants in the OSPAR Maritime Area have been phased out completely,” with mercury emissions from the sector having ceased in mid-2018 and the 2019 reporting round confirming full conversion or shutdown across all remaining sites (OSPAR Commission, 16 Dec 2020). In the United States, USGS confirms that only one mercury-cell chlor-alkali plant still operated in 2025, effectively representing the tail end of the US phase-out (USGS MCS 2026). The Minamata Convention itself set 2025 as the Annex B, Part I phase-out deadline for this process, codifying at treaty level what Europe had already substantially completed years earlier.

5.2 Thermometers, batteries, and measuring devices

Traditional mercury thermometers have been almost entirely replaced. USGS notes that “Galinstan” — a gallium-indium-tin alloy — substitutes for mercury in the few remaining liquid-in-glass thermometers, while digital thermometers have replaced most mercury units altogether. Mercury medical devices such as sphygmomanometers (blood pressure gauges) have similarly been phased out across most health systems in favor of electronic and aneroid alternatives. On batteries, USGS confirms mercury is “no longer used in most batteries and paints manufactured in the United States,” with lithium, nickel-cadmium, and zinc-air batteries replacing mercury-zinc cells, and indium compounds substituting for mercury in alkaline batteries — a substitution pattern mirrored globally under the Minamata Convention's Annex A product phase-out list, which bans most mercury battery types outright (USGS MCS 2026).

5.3 Dental amalgam and cosmetics: the two hold-out consumer uses

Despite decades of substitution pressure from ceramic composites and resin-based fillings, dental amalgam remains 27% of U.S. mercury consumption and is now on a hard international clock — COP-6's November 2025 decision sets a global manufacture/import/export phase-out date of 2034, with an exemption preserved for cases where “its use is considered necessary by the dental practitioner based on the needs of the patient” (European Network for Environmental Medicine, 13 Nov 2025). The EU moved earlier and faster: amalgam use for the general population banned from 1 January 2025 and manufacturing/import banned from 1 July 2026 under Regulation (EU) 2024/1849, with Norway, Sweden, and Denmark having already banned amalgam domestically years before the EU-wide rule (European Parliament Legislative Train, Revision of the Mercury Regulation). In the U.S., the Indian Health Service announced it will discontinue dental amalgam use starting in 2027, following the COP-6 decision, according to the American Dental Association; the FDA has separately issued guidance discouraging amalgam use in high-risk groups (pregnant women, children, and people with certain health conditions) without imposing an outright US ban (ADA statement, 11 Feb 2026). On cosmetics, mercury-containing skin-lightening creams and soaps remain listed among products USGS flags as still potentially containing mercury in some markets; these fall under Minamata Annex A's mercury-added products list, with COP-5 and the EU's 2024/1849 amendment both tightening the phase-out timeline for cosmetic mercury compounds to 2025 (USGS MCS 2026).

5.4 Fluorescent lighting and the LED transition

The LED transition is steadily eliminating fluorescent lamps, the largest mercury-added lighting category; USGS states domestic mercury consumption “will continue to decline owing to increased use of LED lighting and consequent reduced use of conventional fluorescent tubes and compact fluorescent bulbs” (USGS MCS 2026). COP-5 set 2026–2027 phase-out dates for specific compact and linear fluorescent lamp categories under Annex A, with a small number of specialty lamp types granted extensions to 2027 where no viable substitute yet exists (IISD Earth Negotiations Bulletin, COP-5 summary). Indium-containing LEDs are the direct substitute technology displacing mercury-vapor fluorescent tubes across both commercial and residential lighting markets.

Why it matters: mercury demonstrates what a fully mature substitution cycle looks like — nearly every historical industrial use (thermometers, batteries, most lighting, most chlor-alkali capacity) has already been engineered out via non-mercury alternatives that are cheaper or treaty-mandated. The hold-out uses — dental amalgam, cosmetics in some markets, and ASGM gold recovery — are now all under binding phase-out schedules (2034, 2025, and a stated 2032 target respectively), leaving mercury as a case study in a metal being regulated out of the economy on a fixed timeline.

Regulated Compound Classes: Cinnabar, Calomel, Methylmercury, and Thimerosal

6.1 Cinnabar (HgS)

Cinnabar, mercury(II) sulfide, is the principal mercury ore and the source of virtually all historical primary mercury mining, including at Spain's Almadén mine before its 2003 closure. EU Regulation 2017/852 Annex I lists “Cinnabar ore” explicitly among the mercury compounds banned for export from the EU from 1 January 2018, alongside mercury sulfide (HgS) itself (EU Regulation 2017/852, Annex I). The EU's separate submission to the Minamata Secretariat confirms that mercury extracted from cinnabar ore within the EU is treated as waste requiring final disposal, with “no re-use, no recycling, no reclamation” permitted (EU submission to Minamata Secretariat on releases).

6.2 Calomel (Hg₂Cl₂) and other listed compounds

Mercury(I) chloride — historically known as calomel and once used in medicine and pigments — appears by name in EU Regulation 2017/852 Annex I as banned for export from 1 January 2018, alongside mercury(II) oxide. Two further compounds, mercury(II) sulphate and mercury(II) nitrate, were added to the export ban from 1 January 2020 (EU Regulation 2017/852, Annex I). The regulation also separately bans, from 1 January 2018, any “mixtures of mercury with other substances, including alloys of mercury, with a mercury concentration of at least 95% by weight” — closing an obvious loophole where near-pure mercury could otherwise be exported as an “alloy.”

6.3 Methylmercury and the fish-consumption exposure pathway

Methylmercury is not directly traded or manufactured at scale; it forms environmentally when inorganic mercury released to water or soil is converted by microbial action into an organic form that bioaccumulates up the aquatic food chain into fish and shellfish. This transformation pathway is the central human-health rationale underlying the Minamata Convention's air- and water-emissions provisions, and is the specific mechanism responsible for the original Minamata Bay poisoning that gave the treaty its name (Minamata Convention booklet, UNEP Secretariat). EU technical guidance sets biota/fish mercury limits at 20 µg/kg wet weight and surface-water mercury limits at 0.07 µg/l under related EU environmental quality standards tied to the Mercury Regulation framework (EU submission to Minamata Secretariat on releases). In the United States, the FDA and EPA jointly maintain fish-consumption advice using an allowable average mercury concentration threshold of 0.15 µg/g for fish recommended at three servings per week (the “Best Choices” category), rising to 0.23 µg/g for one serving per week (“Good Choices”), with any fish above 0.46 µg/g placed in a “Choices to Avoid” category (FDA, Technical Information on FDA/EPA Fish Advice). The FDA's standing advisory has long singled out shark, swordfish, king mackerel, and tilefish as species to avoid due to high mercury levels (FDA/EPA 2004 Advice on Mercury in Fish and Shellfish), and EPA maintains parallel fish-consumption guidance updated as recently as March 2026 (US EPA, Guidelines for Eating Fish that Contain Mercury).

6.4 Thimerosal and the narrower preservative carve-out

Thimerosal, an organomercury compound used as a preservative in some multi-dose vaccine vials, sits in a narrower regulatory carve-out than most mercury compounds. The Minamata Convention's Annex A product phase-out list has historically preserved exceptions for preservatives where no effective and safe substitute is available, a category into which vaccine-preservative uses have fallen in past COP decisions on mercury-added products, distinguishing thimerosal's treatment from the blanket bans applied to cosmetics, batteries, and lamps (Minamata COP-5 decisions document, Annex A amendments). The World Health Organization's International Programme on Chemical Safety has repeatedly assessed thimerosal in vaccines as posing no demonstrated health risk at the doses used, supporting its continued but declining use, particularly in multi-dose vial formulations distributed in lower-income countries where single-dose alternatives remain more costly; global usage has declined as single-dose, preservative-free vaccine presentations have expanded, but thimerosal has not been eliminated worldwide.

Why it matters: the compound-level specificity of both the Minamata Convention and EU Regulation 2017/852 — naming cinnabar ore, calomel, and specific mercury salts individually — closes trade loopholes that a metal-only ban would leave open, and reflects lessons learned from decades of mercury moving through commerce disguised as ore, alloy, or industrial chemical rather than as regulated elemental mercury.

The Unfinished Business: VCM Catalysts, Coal-Fired Emissions, Historical Health Toll, and a Market With No Exchange

7.1 VCM acetylene-route production: China's mercuric-chloride catalyst problem

China's coal-and-calcium-carbide-based acetylene route to vinyl chloride monomer (the feedstock for PVC) uses mercuric chloride (HgCl2) as a catalyst for acetylene hydrochlorination — an older, cheaper process than the ethylene-based route used almost everywhere else in the world, which requires no mercury at all. Academic literature estimates that “the loss of mercury from the commercial production of VCM in these units is in the region of 600–1,000 tonnes Hg per annum,” adding that “at present about 60% of annual mercury production is used to manufacture the catalyst” (Journal of the American Chemical Society, mercury-free acetylene hydrochlorination catalyst research, Cardiff University repository). USGS MCS 2026 corroborates this directly, noting that “mercury compounds were used as catalysts in the coal-based manufacture of vinyl chloride monomer in China” (USGS MCS 2026). Because China's VCM industry is fed substantially by primary and legacy mercury stocks, the Zero Mercury Working Group argues its phase-out is “even more important” precisely because it is “significantly supplied by primary mercury mining” (Zero Mercury Working Group, COP-6 Statement on VCM, 3 Nov 2025).

7.2 The Annex B phase-down timetable and the COP-6 deferral

Minamata Annex B, Part II bars new mercury-based VCM facilities outright and requires existing Parties to phase out mercury use in VCM production once the COP determines mercury-free catalysts “based on existing processes have become technically and economically feasible,” starting a clock that runs five years from that determination (Minamata Secretariat, COP-6 VCM working document). China ratified the Convention in 2016 and its Ministry of Ecology and Environment and Ministry of Industry and Information Technology jointly banned mercury use in new VCM manufacturing processes from 16 August 2017, the Convention's entry-into-force date, while allowing existing mercury-based plants to continue operating (China's submission to the Minamata Convention Secretariat on mercury-free VCM production). Domestically, China had earlier ordered a complete phase-out of mercury use by the PVC industry by 2015, a target that was not met in full, followed by the higher-profile 2013 Minamata signature commitment (Chemical & Engineering News, “How Outsiders Are Helping China's Vinyl Industry Kick the Mercury Habit,” 2016). At COP-6 in November 2025, the Zero Mercury Working Group pressed the Secretariat to formally determine that mercury-free catalysts are “readily available, as well as technically and economically feasible,” which would trigger the five-year countdown to a binding phase-out; that determination was not adopted at COP-6, with the issue deferred to COP-7 amid Chinese opposition, and some 2026 commentary now anticipates a full ban aligned with the treaty's 2032 cessation-of-primary-mining target (Futu News market commentary, 29 Jan 2026).

7.3 Coal combustion emissions and Article 8 BAT/BEP requirements

Stationary combustion of coal is the second-largest source of anthropogenic mercury emissions worldwide at 474 tonnes per year, behind only ASGM, according to the UNEP Global Mercury Assessment figures cited in USGS MCS 2026 (USGS MCS 2026). Minamata Article 8 requires Parties to control and, where feasible, reduce mercury emissions from specified stationary source categories — including coal-fired power plants, coal-fired industrial boilers, and certain smelting operations — using best available techniques (BAT) and best environmental practices (BEP), with new sources required to apply BAT/BEP from the Convention's entry into force and existing sources given longer compliance timelines set by national plans. Because coal combustion emissions are diffuse (released through flue gas across thousands of individual plants) rather than concentrated in a single traded commodity flow, Article 8 implementation depends heavily on national air-pollution control regimes — scrubber and activated-carbon injection retrofits, in particular — rather than a single global phase-out date of the kind used for chlor-alkali or dental amalgam.

7.4 Minamata disease and the epidemiological record: Chisso, the Faroes, and Seychelles

The treaty's namesake disaster occurred at Minamata, Japan, where the Chisso Corporation's chemical factory released methylmercury-contaminated wastewater into Minamata Bay between 1932 and 1968 as a byproduct of acetaldehyde production that itself used a mercury catalyst. The contamination bioaccumulated through the marine food chain and, upon consumption by the local population, caused what is now known as Minamata disease; official Japanese government recognition eventually certified 2,265 individuals as afflicted, of whom 1,784 died as a result of the poisoning or the disease, with the first clinical description published by a Chisso company-hospital physician on 1 May 1956 and the causal link to mercury confirmed by Kumamoto University researchers in 1963 (Chisso Corporation historical record). Chisso did not stop using a mercury catalyst in acetaldehyde production until May 1968.

Two later prospective cohort studies became the scientific backbone for modern methylmercury exposure limits. The Faroe Islands cohort, tracking children exposed prenatally through maternal consumption of pilot-whale meat (which concentrates methylmercury), found associations between prenatal mercury exposure and deficits in attention, language, and memory, becoming one of the most heavily cited datasets in setting reference doses for methylmercury. The Seychelles Child Development Study, following a population with high fish consumption but different exposure patterns, produced comparatively more mixed findings on neurodevelopmental effects, and the divergence between the two cohorts has driven decades of follow-on research into dose, timing, and co-exposure factors (such as beneficial fish nutrients) that regulatory bodies including the FDA and EPA weigh when setting fish-consumption advisories. Both cohorts remain foundational references underpinning the FDA/EPA joint fish advisory framework described in Section 6.3 (FDA, Technical Information on FDA/EPA Fish Advice).

7.5 Prices and benchmarks: no exchange, a flask-based physical market

Mercury has no LME contract, no futures market, and no centralized exchange of any kind — a direct structural consequence of its treaty-driven trade restrictions, which make a liquid, freely tradable commodity market legally impossible for most jurisdictions. Physical trade that does occur is denominated in the traditional 34.5 kg flask unit and assessed periodically by trade publications rather than through daily exchange settlement. USGS's own price series — the only primary-source, government-published mercury price benchmark — tracks the average unit value of US imports: $29/kg in 2021, $33/kg in 2022, $22/kg in 2023, and $50/kg in 2024, more than doubling year-on-year as legal supply continued to tighten (USGS MCS 2026). Grey-market and regional retail listings, while not primary benchmarks, illustrate the wide dispersion in prices paid outside formal import channels, with Indian retail mercury listings in late 2025 ranging roughly ₹30,600–46,700 per kilogram (approximately $370–560/kg) depending on purity and stated end use, underscoring how far grey-market and specialty-use pricing can diverge from the customs-based USGS benchmark (IndiaMART, Delhi liquid mercury listings, accessed 2025–26). US import sourcing itself is heavily concentrated: for 2021–24, Canada supplied 69% of US mercury imports and China (including Hong Kong) supplied 31%, with other sources under 1% (USGS MCS 2026).

Source: USGS MCS 2026, mercury chapter.

Why it matters: the absence of a formal exchange or futures contract is not an oversight — it is the direct result of a metal that most of the world has agreed, by treaty, to stop trading. VCM catalyst use and coal combustion emissions represent the two largest gaps left in that wind-down: one an industrial process concentrated in a single country awaiting a COP determination, the other a diffuse emissions source requiring plant-by-plant retrofit rather than a single bannable transaction.