Two bans, not one: the structure of the polar HGO and HFO rules
The most common error a practitioner makes with polar fuel rules is treating them as a single global prohibition. They are not. MARPOL Annex I holds two distinct regulations, drafted eleven years apart, with different verbs, different scope, and different relief mechanisms.
Regulation 43 covers the Antarctic and has been in force since 1 August 2011. It prohibits the carriage in bulk as cargo, and the carriage and use as fuel, of heavy grade oil in the sea area south of latitude 60 degrees South. There is no waiver for ship type, no construction-based grace period, and no coastal-state opt-out. A ship transiting the Antarctic area cannot burn HGO and cannot even carry it as cargo through those waters.
Regulation 43A covers Arctic waters and entered into force on 1 July 2024. It prohibits the use and carriage for use as fuel of heavy fuel oil by ships in Arctic waters. The verb set is narrower than the Antarctic rule: it reaches the bunkers a ship uses and the bunkers it carries for its own use, not a cargo of heavy oil in a tanker’s cargo tanks. And it carries two carve-outs that the Antarctic rule does not have: a waiver for ships fitted with protected fuel tanks under Regulation 12A, and an option for Arctic coastal states to waive the rule temporarily for their own flag ships. Both expire on 1 July 2029.
The asymmetry is deliberate. The Antarctic is a no-sovereignty common governed by the Antarctic Treaty 1959 and the Madrid Protocol 1991, with a small, well-resourced expedition fleet that already bunkers distillate. A clean prohibition was politically and operationally feasible in 2010. The Arctic is bordered by sovereign states with mixed fleets, supply chains that ran on HFO, and remote communities dependent on heavy-oil-fueled shipping. The 2021 drafters bought consensus by phasing the Arctic rule with waivers, and that compromise is the single most criticized feature of Regulation 43A.
Regulation 43: the Antarctic heavy grade oil ban from 2011
The Antarctic ban came out of MEPC 60 in March 2010. The Committee adopted the amendment by Resolution MEPC.189(60), which added a new Chapter 9 to MARPOL Annex I containing a single new Regulation 43. The amendment cleared the standard tacit-acceptance period and entered into force on 1 August 2011. That was also the date the North American Emission Control Area under Annex VI entered into force, though the ECA’s sulphur and NOx controls did not take effect until a year later, on 1 August 2012, so the two regimes did not begin biting on the same day.
Regulation 43 reads against the geographic definition of the Antarctic area already used across MARPOL: the sea area south of latitude 60 degrees South. That line is the same boundary the Antarctic Special Area uses for oil, garbage and sewage, and the same boundary the Polar Code adopts for the southern hemisphere. There is no longitudinal limit. The cap is a complete latitudinal band, so a ship’s position relative to 60 South is the only geographic test that matters.
What Regulation 43 prohibits is precise. A ship may not carry in bulk as cargo, or carry and use as fuel, any of three things in the Antarctic area:
- crude oils with a density above 900 kg/m3 at 15 degrees Celsius;
- oils other than crude with a density above 900 kg/m3 at 15 degrees Celsius, or a kinematic viscosity above 180 mm2/s at 50 degrees Celsius; and
- bitumen, tar and their emulsions.
The structure matters. The first category catches heavy crudes carried by tankers. The second catches residual fuel oils such as the heavy fuel oil grades that dominated marine bunkers before 2020. The third closes a loophole for asphaltic products that might slip the density test. A practitioner reading the rule should note that the density figure (900 kg/m3 at 15 C) is the dividing line between a residual fuel and a distillate: marine gas oil sits well below 900 kg/m3, typically around 840 to 890, while residual grades run 960 to 1010. So in practice the Antarctic ban forces a switch to distillate before crossing 60 South.
The one exception is narrow. The rule does not apply to ships engaged in securing the safety of ships or in a search and rescue operation. There is no exception for a ship that simply finds HFO cheaper, no construction-based waiver, and no coastal-state opt-out. That absence is what makes Regulation 43 the cleaner of the two polar rules.
How operators comply with Regulation 43 in practice
Compliance with the Antarctic rule is a bunkering and tank-management exercise, not a structural one. Expedition cruise ships bound for the Antarctic Peninsula bunker distillate at the southern gateway ports, Ushuaia in Argentina and Punta Arenas in Chile, before crossing the Drake Passage. A ship that arrives with residual fuel in its bunkers cannot burn that fuel south of 60 South, so the operational planning has to ensure the ship is running on compliant fuel, with the heavy-fuel tanks emptied or isolated, by the time it reaches the boundary.
The carriage-as-cargo prohibition rarely bites in the expedition trade because passenger and expedition ships do not carry oil cargo. It bites on any tanker that might otherwise route a heavy crude or residual cargo through the Antarctic area, which is why the rule is written to cover cargo at all. In the fishing and research fleets that operate near the boundary, the practical effect is the same as for cruise ships: switch to distillate before entering, and document the switch.
Tank cleaning is the hidden cost. A ship that has burned HFO needs its fuel-oil service and settling tanks free of residual product before it can run cleanly on distillate, and residual fuel leaves waxy and asphaltenic deposits that distillate does not fully redissolve. The fuel switching operations discipline that the industry built for the IMO 2020 sulphur cap and for emission control areas transfers directly to the Antarctic boundary: plan the changeover early, account for the time the engine needs to run down the heavy fuel in the lines, and log the changeover position and time.
Regulation 43A: the Arctic heavy fuel oil ban from 2024
The Arctic ban took far longer to negotiate and arrived in a more complex form. The Sub-Committee on Pollution Prevention and Response developed the text across its 7th and 8th sessions in 2020 and 2021. MEPC 76, meeting remotely from 10 to 17 June 2021, adopted the amendment by Resolution MEPC.329(76) on 17 June 2021, adding a new Regulation 43A to MARPOL Annex I. The amendment entered into force on 1 July 2024.
Regulation 43A prohibits the use and carriage for use as fuel of heavy fuel oil by ships in Arctic waters. The fuel definition tracks the Antarctic rule’s density and viscosity test: the prohibition covers oils with a density at 15 degrees Celsius above 900 kg/m3 or a kinematic viscosity at 50 degrees Celsius above 180 mm2/s. The “use and carriage for use as fuel” phrasing is the legal heart of the rule. It reaches a ship’s own bunkers, both the fuel it burns and the fuel it carries to burn later, but it does not reach a cargo of heavy oil. That distinction separates Regulation 43A from the broader Antarctic Regulation 43, which also catches carriage in bulk as cargo.
The geographic scope is “Arctic waters” as defined in MARPOL Annex I, which mirrors the Polar Code definition: a sea area north of a line that runs broadly along 60 degrees North in some sectors and steps north around the Norwegian and Russian coasts and through the Bering Strait, rather than a simple latitude cap. Unlike the clean 60 South line in the Antarctic, the Arctic boundary follows a stepped polyline drawn to exclude busy sub-Arctic shipping lanes such as those off northern Norway and the approaches to the White Sea. A navigator cannot rely on a single latitude for the Arctic boundary the way the Antarctic boundary allows.
The Regulation 12A waiver and the coastal-state exemption
The two carve-outs in Regulation 43A are what separate a 2024 in-force date from a 2024 effective ban. They are the reason the Clean Arctic Alliance and other observers argued the rule left most HFO in Arctic use until 2029.
The first carve-out is construction-based. A ship that meets the oil fuel tank protection standards of Regulation 12A, which requires fuel tanks of a certain capacity to be set in from the hull by a protective distance, does not have to comply with Regulation 43A until 1 July 2029. Regulation 12A applies to ships with an aggregate oil fuel capacity of 600 m3 or more delivered on or after 1 August 2010, so a large and growing share of the modern fleet carries protected fuel tanks already. For those ships the Arctic HFO ban does not bite until 2029, on the logic that a protected-tank arrangement reduces the spill risk that motivates the rule. The waiver does nothing for black carbon, which is an exhaust emission and is unaffected by where the fuel tank sits.
The second carve-out is jurisdictional. A Party to MARPOL with a coastline bordering Arctic waters may temporarily waive Regulation 43A for ships flying its flag while they operate in waters subject to that Party’s sovereignty or jurisdiction. This exemption also runs to 1 July 2029. It was the price of consensus with the Arctic coastal states, principally Russia and Canada, whose domestic shipping and remote-community supply ran on HFO. The waiver is limited to the waiving state’s own flag ships in its own waters, so it does not open the whole Arctic to HFO, but it removes a large fraction of Arctic HFO consumption from the 2024 prohibition.
Layered on these two, the standard safety and response exceptions apply: ships engaged in securing the safety of ships or in search and rescue, and ships dedicated to oil spill preparedness and response, are exempt. Those exceptions are narrow and operational, not a route for ordinary commercial trade.
The arithmetic the rule produces is blunt. From 1 July 2024, only ships that both lack Regulation 12A protected tanks and fly a flag without a coastal-state waiver, or operate outside a waiving state’s waters, are actually barred from HFO. Everything else is grandfathered to 1 July 2029. The full, exception-free prohibition arrives only on that date.
The density and viscosity test in detail
Both regulations turn on the same physical test, and getting it right is a fuel-quality question that a chief engineer and a bunker surveyor have to settle from the bunker delivery note and the ISO 8217 fuel specification.
Density is measured at 15 degrees Celsius and the threshold is 900 kg/m3. This is the same reference temperature the industry uses for bunker quantity surveys and the same value that appears on the bunker delivery note. Residual fuels sit above it: a typical RMG 380 grade runs around 991 kg/m3 maximum under ISO 8217, and the heaviest RMK 500 grade runs to 1010 kg/m3. Distillates sit below it: DMA marine gas oil runs around 890 kg/m3 maximum, and a typical marine gas oil parcel comes in near 840 to 860. So density alone separates the residual grades the bans target from the distillates that comply.
The viscosity limb catches a non-crude oil with a kinematic viscosity above 180 mm2/s at 50 degrees Celsius. This is the same 50 C reference and the same unit (mm2/s, equal to centistokes) the bunker industry uses for grade naming: RME 180 and RMG 380 are named for their nominal viscosity at 50 C. The viscosity test exists because a blended fuel could be engineered to sit just under the 900 kg/m3 density line while still behaving like a residual fuel; the 180 mm2/s ceiling closes that gap. A fuel that is heavy by either density or viscosity is in scope.
The bitumen, tar and emulsions category in Regulation 43 catches asphaltic products outright, regardless of the density and viscosity numbers, because those products are unambiguously the heaviest end of the oil spectrum and pose the worst spill-persistence problem in cold water.
Why polar HGO and HFO are treated differently from open-ocean fuel
Heavy fuel oil behaves badly in cold water. It is persistent, it does not evaporate or disperse the way lighter oils do, and at low temperatures it becomes more viscous and harder to recover. A spill of residual fuel in ice-covered or near-freezing water can persist for years, and the mechanical recovery techniques that work in temperate water (skimmers, booms) are degraded by ice, darkness, remoteness, and the absence of response infrastructure. The polar bans exist because the consequence of a heavy-oil spill in those waters is far worse, and the response far weaker, than anywhere else a ship trades.
The spill-persistence logic is the same in both poles, which is why both regulations use the same density and viscosity definition. What differs is the second motive: black carbon. Black carbon is the soot fraction of engine exhaust, and HFO combustion produces more of it than distillate combustion. When black carbon deposits on Arctic snow and sea ice it lowers the surface reflectivity (the albedo) and speeds melting, a short-lived climate-forcer effect that compounds the carbon-dioxide warming the IMO greenhouse-gas strategy targets. The black-carbon concern is specific to the Arctic, where the ice and snow surfaces sit downwind of growing ship traffic, and it gave the Arctic rule a climate rationale on top of the spill-risk rationale. The Antarctic, surrounded by ocean and far from the major routes, was driven mainly by spill risk.
A point of precision for the practitioner: Regulation 43A is written as a fuel-property prohibition, not a black-carbon emission limit. The black-carbon problem motivated the rule, but the legal text bans a class of fuel by density and viscosity, not a measured soot rate. IMO continues to work on black-carbon measurement and control through the Sub-Committee on Pollution Prevention and Response, and any future direct black-carbon limit would be a separate instrument.
Enforcement, surveys, and the Oil Record Book
Enforcement of the polar fuel bans runs through the standard MARPOL Annex I machinery: flag-state survey and certification, port state control inspection, and the Oil Record Book. There is no separate polar certificate for the fuel ban itself; the prohibition is a behavioral rule that a ship demonstrates compliance with through its records and its bunkers.
The Oil Record Book Part I records bunkering and internal transfers, so an inspector can read the changeover from HFO to distillate before the polar boundary against the ship’s logged position and time. A ship that recorded burning residual fuel south of 60 South, or in Arctic waters without a valid waiver, would be exposed to a deficiency finding. The bunker delivery note under Annex VI Regulation 18 and the retained fuel sample give the inspector the fuel’s density and viscosity, which is the direct evidence of whether the bunkers were in scope of the ban.
For Regulation 43A, the survey question is also whether a waiver applies. A ship claiming the Regulation 12A construction waiver has to show that its fuel tank arrangement meets the protected-tank standard, which is a matter of the ship’s approved drawings and its IOPP certificate supplement. A ship claiming a coastal-state exemption has to be flying the flag of the waiving state and operating in that state’s waters, which a port-state inspector in a third country would scrutinize closely. Port state control under the regional memoranda, including the Paris MOU and the Tokyo MOU, can detain a ship for an Annex I deficiency, and burning a banned fuel in a banned area is the kind of clear-cut finding that supports detention rather than a deficiency with a rectification window.
The practical enforcement gap is the remoteness of polar waters. There is little chance of an inspection mid-voyage in the high Arctic or off the Antarctic Peninsula, so enforcement falls back on the records inspected at the next port of call and on the documentary trail. That is why the Oil Record Book entries and the bunker samples carry so much weight: they are the evidence that survives the voyage.
Interaction with Regulation 12A and the protected-tank fleet
The interaction between the Arctic ban and Regulation 12A is the part of the regime that surprises operators most. Regulation 12A requires that ships with an aggregate oil fuel capacity of 600 m3 or more, delivered on or after 1 August 2010, arrange their fuel tanks with a protective distance from the bottom and side shell, so that a grounding or collision does not breach the fuel tank directly. The rule was a spill-prevention measure aimed at bunker tanks, in the same family as the double-hull requirement for cargo tanks.
Regulation 43A then uses Regulation 12A compliance as the trigger for its construction waiver. The drafting logic is that a protected-tank ship presents a lower spill risk if it grounds in Arctic ice, so it can be allowed to keep burning HFO until 2029 while non-protected ships have to stop in 2024. The waiver rewards the spill-prevention engineering even though it does nothing for black carbon. This is the structural seam the critics point to: the rule that was supposed to clean up Arctic fuel exempts, until 2029, exactly the modern protected-tank ships that make up the bulk of the fleet, on a spill-risk argument that ignores the climate motive.
A practitioner planning Arctic operations between 2024 and 2029 therefore has to know the ship’s Regulation 12A status precisely. A 600 m3-or-more ship delivered on or after 1 August 2010 almost certainly has protected tanks and qualifies for the waiver. An older ship, or a smaller ship below the 600 m3 capacity line that was never required to fit protected tanks, does not get the waiver and has to comply with the HFO ban from 1 July 2024. The capacity line and the delivery date are the two facts that decide it.
The criticism: how much HFO the Arctic ban actually removes
The central criticism of Regulation 43A is that its waivers and exemptions leave most Arctic HFO use in place until 2029. The Clean Arctic Alliance and several delegations argued during the negotiation that the combination of the Regulation 12A construction waiver and the coastal-state exemption would exempt the majority of HFO carried and burned in Arctic waters in the first five years, so the in-force date of 1 July 2024 marked the start of a phase-in rather than the start of an effective ban.
The argument runs on two facts. First, the protected-tank waiver covers a large share of the modern fleet, because Regulation 12A has applied to new ships since 2010 and most ships above the 600 m3 fuel-capacity threshold built in the last fifteen years carry protected tanks. Second, the coastal-state exemption covers a large share of Arctic-domestic traffic, because the states with the most HFO-fueled Arctic shipping, principally Russia, are the states able to waive the rule for their own flag ships in their own waters. Between them, the two carve-outs reach much of the HFO actually consumed in the Arctic in the 2024 to 2029 window.
The counter-argument from the rule’s drafters is that a phased ban that the coastal states would accept is better than a clean ban they would block or ignore, and that the 2029 backstop is firm. From 1 July 2029 there is no construction waiver and no coastal-state exemption, and the only remaining exceptions are the narrow safety and oil-spill-response ones. Whether the 2024 to 2029 phase-in meaningfully reduced Arctic HFO use, or simply deferred the cleanup to 2029, is the open empirical question that the black carbon monitoring work and the Arctic shipping statistics will answer over the phase-in period.
The contrast with the Antarctic rule sharpens the point. The Antarctic Regulation 43 had no waivers and bit in full on 1 August 2011, and the small Antarctic fleet adapted by bunkering distillate at the gateway ports. The Arctic rule, facing a larger and more politically complex fleet, traded a clean 2024 ban for a phased 2024-to-2029 one. The Antarctic shows what an unwaivered ban looks like; the Arctic shows the cost of consensus.
Compliant fuels and the switch away from HFO
Compliance with both bans means burning a fuel that sits below the density and viscosity thresholds. The obvious candidate is marine gas oil and other distillates, which are well under 900 kg/m3 and well under 180 mm2/s, and which the fleet already uses inside emission control areas and since the IMO 2020 sulphur cap brought 0.50 percent global sulphur limits. A ship that already switches to distillate for an ECA can use the same fuel for the polar boundary, and the operational discipline of fuel switching operations carries over directly.
The alternative fuels under development complicate the picture in a useful direction. A ship running on LNG as marine fuel, methanol, or ammonia is outside the density and viscosity test entirely, because those fuels are not oils in the sense the regulation defines. The polar bans therefore push, indirectly, toward the same alternative-fuel transition that decarbonization technologies and the IMO net-zero framework are driving for greenhouse-gas reasons. An LNG-fueled expedition ship in the Antarctic, or a methanol-fueled ship in the Arctic, complies with the fuel ban as a side effect of its decarbonization choice.
Biofuels and blended fuels need care. A blend can be engineered to sit near the 900 kg/m3 line, which is exactly why the regulation carries the 180 mm2/s viscosity limb as a second test. A biofuel blend that meets the density limit but exceeds the viscosity limit is still a banned fuel. The chief engineer cannot assume that a low-carbon label means a polar-compliant fuel; the fuel has to pass both limbs of the test.
Relationship to the Polar Code and the Special Area regime
The fuel bans are one layer in a stacked polar regime, and a practitioner has to read them alongside the others rather than in isolation. The Polar Code, mandatory since 1 January 2017 through MARPOL and SOLAS Chapter XIV, adds discharge and construction uplifts; in the south the fuel ban also stacks with the Antarctic Special Area regime and the discharge prohibitions covered in detail in the MARPOL Annex I Special Areas article. The point that matters for Regulation 43 is the division of labor: the Special Area governs what a ship may put into the sea, while the fuel ban governs what fuel a ship may carry and burn in the first place. A ship can be fully compliant with the discharge rules and still breach Regulation 43 by burning HFO, and vice versa. The Arctic carries no MARPOL Special Area under any Annex, so there Regulation 43A and the Polar Code discharge uplift do the work that the Special Area does in the south.
The relief mechanics are where the two fuel regulations diverge most sharply, and they repay close reading. Regulation 43 carries no waiver and no exemption: the only carve-outs are the operational ones for a ship securing the safety of ships or engaged in search and rescue, which suspend the prohibition for the duration of that activity and nothing more. There is no construction grace period and no discretion in any Administration to relieve a ship of the Antarctic prohibition. Regulation 43A, by contrast, is built around two time-limited carve-outs that a flag or coastal Administration administers directly. The Regulation 12A protected-tank waiver is self-executing: a ship that holds approved drawings showing protected fuel tanks does not need any positive act by the Administration to claim it, but a port-state inspector will test the claim against those drawings, so the documentary burden sits on the ship.
The coastal-state exemption works the other way around. It is a discretionary act by an Arctic coastal Party, and a ship cannot claim it unless that Party has actually exercised the discretion for the ship’s flag and the ship is operating in waters under that Party’s sovereignty or jurisdiction. The exemption does not travel with the ship outside those waters, and it cannot be invoked by a ship of a third flag even inside them. Both carve-outs share a hard sunset: on 1 July 2029 the waiver and the exemption both lapse, and from that date the only surviving relief is the same narrow safety-of-ships and search-and-rescue carve-out that Regulation 43 has always had. A practitioner managing an Arctic fleet through the phase-in therefore has to track three separate facts for each ship: its Regulation 12A status, the existence of any relevant coastal-state exemption, and the 2029 sunset that erases both.
Worked compliance picture: an Arctic transit, 2026
Consider a 12,000 GT general cargo ship, delivered in 2014, aggregate oil fuel capacity 1,200 m3, flying a non-Arctic flag, planning a summer 2026 transit through Arctic waters along the Northern Sea Route under a Russian icebreaker escort.
The Regulation 12A question comes first. The ship was delivered after 1 August 2010 and has more than 600 m3 of fuel capacity, so it is subject to Regulation 12A and, if its tanks meet the protected-tank standard shown on its approved drawings, it qualifies for the Regulation 43A construction waiver until 1 July 2029. On that basis the ship could continue to burn HFO in Arctic waters through 2026, provided the drawings confirm protected tanks.
The coastal-state exemption does not help this ship, because it flies a non-Arctic flag and so cannot benefit from a Russian flag-state waiver. If the ship lacked protected tanks, it would have to burn a compliant distillate, switching before the Arctic boundary and logging the changeover in the Oil Record Book.
The operator’s safe choice, given the waiver expires in three years and the ship will trade beyond 2029, is to plan the distillate switch now and treat the Arctic boundary like an ECA boundary: bunker compliant fuel before entry, isolate the heavy-fuel tanks, run the engine down onto distillate ahead of the line, and document the position and time. That plan complies regardless of the waiver and avoids a fleet-wide fuel-system change in 2029. The same ship bound for the Antarctic would have no waiver to consider at all: it must be on compliant fuel before 60 South, full stop.
Limitations and practitioner notes
These two regulations are precise fuel-property prohibitions, and their limits are as load-bearing as the prohibitions.
The first limit is that the Arctic ban is not effective in full until 1 July 2029. Between 1 July 2024 and that date, a protected-tank ship under Regulation 12A and a coastal-state-flagged ship in its own waters can keep burning HFO. Treating the 2024 in-force date as the date HFO leaves the Arctic is the most common analytical error; the operative date for an unwaivered ban is 2029. Reading the ship’s Regulation 12A status and the relevant coastal-state waivers is part of any Arctic compliance assessment in the phase-in window.
The second limit is the scope difference between the two rules. The Antarctic Regulation 43 catches carriage in bulk as cargo, so a tanker cannot route an HGO cargo through the Antarctic area; the Arctic Regulation 43A reaches only use and carriage for use as fuel, so it does not bar a cargo of heavy oil. Confusing the two scopes, in either direction, produces a wrong compliance conclusion.
The third limit is that the bans are fuel-property rules, not emission limits. Regulation 43A is justified partly by black carbon, but it bans a class of fuel by density and viscosity rather than capping a measured soot rate. A future direct black-carbon control would be a separate instrument, and a ship can comply with the fuel ban while still emitting black carbon from a compliant fuel.
The fourth limit is the boundary geometry. The Antarctic boundary is a clean 60 South latitude line, but the Arctic boundary in MARPOL Annex I follows a stepped polyline that excludes some sub-Arctic lanes. A navigator who treats the Arctic boundary as a simple latitude will misjudge where the ban begins. The exact Arctic-waters definition in Annex I, read with the chart, is the authority.
The fifth limit is enforcement reach. Mid-voyage inspection in polar waters is rare, so the regime depends on the documentary trail: the Oil Record Book changeover entries, the bunker delivery notes, and the retained fuel samples inspected at the next port of call. A clean record of switching to compliant fuel before the boundary, with position and time, is the practical evidence of compliance, and its absence is the practical exposure. The exceptions for ships securing the safety of ships, search and rescue, and oil-spill response are narrow and operational, not a route for commercial trade, and a ship invoking them has to be able to show the qualifying activity.
A final note on numbers. The density and viscosity thresholds (900 kg/m3 at 15 C, 180 mm2/s at 50 C) and the dates (1 August 2011 for Regulation 43, 1 July 2024 and 1 July 2029 for Regulation 43A) are the governing figures, taken from Resolutions MEPC.189(60) and MEPC.329(76) and the consolidated Annex I text. Grade examples such as RMG 380 at 991 kg/m3 or DMA at 890 kg/m3 are representative ISO 8217 specification values for illustration; the governing density and viscosity for any specific bunker parcel are those on its bunker delivery note and certificate of quality, against which the in-scope test should always be checked.
The negotiating timeline: 2010 to 2029
The two bans grew out of the same 2009-to-2010 IMO work programme but separated into different tracks because the politics of the two poles diverged. Tracing the sequence helps a practitioner understand why the Arctic rule looks the way it does.
The Antarctic ban moved fast. MEPC 60 in March 2010 adopted Resolution MEPC.189(60), the Chapter 9 amendment carrying Regulation 43, and the tacit-acceptance procedure brought it into force on 1 August 2011. The North American Emission Control Area was designated and in force from that same date, but its sulphur and NOx controls only took effect on 1 August 2012, so an operator crossing 60 South in 2011 faced the Antarctic fuel ban without yet facing the NA-ECA limits. The Antarctic fleet, small and already shifting to distillate, absorbed the rule without a phase-in. There was little resistance because no major shipping nation had a domestic HFO-fueled trade in Antarctic waters to protect.
The Arctic ban took more than a decade. The IMO Assembly first called for work on an Arctic HFO measure in 2017, and the Sub-Committee on Pollution Prevention and Response developed the text across PPR 6 in 2019, PPR 7 in February 2020, and PPR 8 in March 2021. MEPC 75 in November 2020 approved the draft amendment, and MEPC 76 adopted it as Resolution MEPC.329(76) on 17 June 2021. The long gestation reflected the negotiation over the waivers: the coastal states would not accept a clean 2024 ban, and the compromise that emerged paired a 1 July 2024 in-force date with a 1 July 2029 backstop for the protected-tank and coastal-state carve-outs.
The 2029 date is the one to watch. On 1 July 2029 the Regulation 12A construction waiver and the coastal-state exemption both end, and Regulation 43A applies to every ship in Arctic waters subject only to the narrow safety, search-and-rescue, and oil-spill-response exceptions. A fleet planner whose ships will trade in the Arctic past 2029 should treat that date, not 2024, as the operative deadline for a fuel-system or fuel-supply change, because the protected-tank waiver that covers the modern fleet through the phase-in disappears on it.
Comparison with other marine fuel-quality regimes
The polar bans are fuel-quality rules, and reading them against the other fuel-quality regimes a ship already complies with shows where they overlap and where they stand alone. The dominant overlap is with the sulphur regime under MARPOL Annex VI Regulation 14. The IMO 2020 sulphur cap limits fuel sulphur to 0.50 percent globally and 0.10 percent inside emission control areas, and a ship can meet the 0.50 percent cap by burning a very-low-sulphur fuel oil that is still a residual fuel above 900 kg/m3. So an Annex VI-compliant fuel is not automatically a polar-compliant fuel: a VLSFO can satisfy the sulphur cap and still be a banned heavy grade oil in the Antarctic. The two regimes regulate different fuel properties (sulphur content for Annex VI, density and viscosity for the polar bans), and a ship has to clear both tests.
The overlap with the ECA distillate switch is closer. A ship that switches to 0.10 percent distillate for an ECA is burning marine gas oil or a light distillate that sits below the polar density and viscosity thresholds, so the same fuel and the same fuel switching operations discipline that meet the ECA limit also meet the polar ban. This is why operators who already run distillate inside ECAs find the polar boundary a familiar operation rather than a new one.
The polar bans stand alone in catching density and viscosity directly. No other MARPOL fuel rule prohibits a fuel for being heavy as such; Annex VI caps sulphur, the NOx code caps nitrogen-oxide emissions, and the greenhouse-gas measures cap carbon intensity, but only Regulations 43 and 43A bar a fuel for its density and viscosity. That makes the polar bans the only place in the convention where the physical heaviness of the fuel, the property that drives spill persistence and black-carbon output, is itself the regulated quantity.
See also
- MARPOL Annex I: oil pollution prevention
- MARPOL Annex I Reg 12A: oil fuel tank protection
- MARPOL Annex I Reg 33: crude oil washing
- Antarctic Special Area and Polar Code
- Polar Code
- SOLAS Chapter XIV: polar waters
- Black carbon and Arctic shipping
- Heavy fuel oil
- Marine gas oil
- MARPOL Annex VI Reg 14: sulphur cap
- IMO 2020 sulphur cap
- Fuel switching operations
- Emission control areas
- Antarctic Treaty 1959
- Madrid Protocol 1991
- Calculator catalogue