Marine Crew Accommodation: MLC 2006 Standards

MLC 2006 Title 3 sets binding minimum dimensions, environmental standards, and welfare facilities for every seafarer on a ship that flies the flag of a ratifying state. Standard A3.1 specifies a headroom floor of 203 cm, sleeping-room floor areas graded by ship tonnage and berth count, sanitary ratios no worse than one fixture per six persons without private facilities, and an obligation to provide recreational spaces. The IMO Code on Noise Levels on Board Ships, mandatory under SOLAS II-1/3-12 from July 2014, adds 60 dB(A) in sleeping rooms and 65 dB(A) in mess and recreation spaces as an outer envelope. Ships built before MLC entry into force on 20 August 2013 carry grandfathering rights on dimensional requirements under Regulation 3.1 paragraph 2, but no exemption from operational titles. Port-state control officers boarding under MLC Title 5 can issue a detention for accommodation deficiencies alone.

Why accommodation has its own MLC title

The ILO had been writing seafarer-accommodation rules since the 1949 Accommodation of Crews Convention (No. 92). By 2006, the ILO’s maritime conventions numbered 68 instruments of varying ratification and enforcement quality. The MLC consolidation brought 37 of them into a single text with a unified certification and inspection regime. Accommodation received its own title, Title 3, because the conditions seafarers live in directly affect fatigue, health, and the ability to stand a safe watch, and because prior surveys by the International Transport Workers’ Federation had documented widespread non-compliance with Convention 92 minimums on sub-standard vessels.

MLC 2006 applies to all ships of 500 GT and above engaged in international voyages, and to all ships registered in ratifying states regardless of voyage type, unless an explicit exemption applies (for example, ships solely in internal waters). Title 3 subdivides into two regulations: Regulation 3.1 covering accommodation and recreational facilities, and Regulation 3.2 covering food and catering.

Regulation 3.1 and Standard A3.1: scope and entry-into-force date

Regulation 3.1 contains the principle; Standard A3.1 contains the detail. Standard A3.1 runs to 19 paragraphs covering location, construction, heating, ventilation, headroom, floor area, sleeping rooms, mess rooms, hospital accommodation, sanitary facilities, recreational amenities, personal clothing storage, and the prohibition on charging the seafarer for any compulsory accommodation service.

The convention entered force on 20 August 2013, ninety days after meeting the ratification threshold of thirty states representing at least 33 percent of world merchant shipping tonnage. Ships contracted for construction before that date and delivered before the flag state’s ratification are subject to Regulation 3.1 paragraph 2: they retain compliance status under the predecessor convention (ILO No. 92 or No. 133, whichever the flag state had in force) and need not be retrofitted to Standard A3.1 dimensions. This grandfathering is not absolute. The flag state can, and in practice does, specify the extent of equivalency; a ship changing flag to a state that had never ratified Convention 92 or 133 loses the shelter of the grandfather clause.

Headroom and structural minimums

Standard A3.1 paragraph 6(c) sets 203 cm as the minimum clear headroom in all accommodation spaces. The number is not arbitrary: it corresponds to the 97th percentile male stature for the global seafarer population at the time of drafting, with a margin that allows comfortable movement while wearing headgear or carrying a lifejacket. The 203 cm floor is a finished-deck to finished-deckhead measurement, not a structural clearance; cable trays, lighting fittings, and ducts that reduce clearance below 203 cm constitute a technical deficiency.

Standard A3.1 paragraph 6(a) requires that accommodation spaces be constructed with structural fire protection, insulation materials that do not promote the growth of vermin, and surfaces that are durable and easy to clean. Paragraph 6(b) prohibits the location of sleeping rooms below the load line in the mid-ship or forward sections unless the ship’s design makes any other location impractical, a concession that the IMO’s ship-design guidelines treat as exceptional rather than routine. Bulkheads and decks separating sleeping rooms from machinery spaces, paint lockers, kitchens, and other high-noise or high-heat sources must carry sufficient insulation to keep the sleeping-room environment within the limits in Standard A3.1 paragraphs 5 and 7.

Floor-area requirements by tonnage band

Standard A3.1 paragraph 9 grades minimum floor area by ship gross tonnage and the occupancy of the sleeping room. The table below reflects the paragraph 9 requirements as in force since MLC entry into force in August 2013:

The figures in this table are net floor areas, excluding the area under a bunk and excluding built-in furniture below 75 cm above the floor. In practice, the 4.5 m² minimum for a single-rating cabin on a large ship is tight: it accommodates a berth of at least 190 cm by 68 cm (the Standard A3.1 paragraph 9(b) berth minimum), a desk, and a small wardrobe. Most classification societies note that ships certificated to the minimum dimensions typically achieve MLC compliance in surveyor inspections, but crews on those vessels consistently rate the cabin space as inadequate in welfare surveys.

Modern bulk carriers and tankers built since 2015 typically provide rating cabins of 7 to 9 m² and officer cabins of 11 to 16 m², which exceeds the standard by a factor of 1.5 to 2. This is partly driven by flag-state requirements that exceed MLC (Liberian and Marshall Islands regulations, for example, set higher floors for certain vessel categories) and partly by shipowner calculations that better accommodation reduces turnover and the cost of crew changes.

The accommodation cabin size calculator can verify whether a proposed cabin layout meets the Standard A3.1 floor for the vessel’s tonnage and berth configuration.

Sleeping room provisions

Standard A3.1 paragraphs 9 and 10 specify what a sleeping room must contain beyond its floor area. Each berth must be individually enclosed, framed, and fitted with a bottom board or equivalent. The mattress must be of a composition that resists vermin. Each sleeping room must have a desk with a drawer large enough for personal documents, a seat, and individual storage space of at least 0.475 m³ per seafarer, plus a hanging locker of at least 475 mm height.

Standard A3.1 paragraph 10 requires that sleeping rooms be directly accessible from a passageway without passing through another seafarer’s cabin, a machinery space, or any space that the occupant would not normally have reason to enter. This access rule has practical consequences for ship design: bunkrooms accessible only through a connecting door to another cabin are non-compliant regardless of their floor area.

Sleeping rooms must not be in the bow forward of the collision bulkhead. Standard A3.1 paragraph 6(b) also discourages placement directly over the propeller or adjacent to the steering gear room because of structure-borne vibration; many shipowner specifications now treat aft cabins within two frames of the stern tube as restricted to storage or non-accommodation use.

Ventilation and thermal comfort

Standard A3.1 paragraphs 5 through 8 address the thermal environment. All sleeping rooms, mess rooms, recreation spaces, and day rooms must have a forced ventilation or air-conditioning system capable of maintaining a comfortable indoor temperature under the design ambient conditions. The convention does not prescribe a specific setpoint; instead, Regulation 3.1 paragraph 1 requires that flag states give effect to the standards in a way that ensures a “decent working and living environment.” In practice, flag state implementation instruments and class society rules typically reference ISO 7547 conditions (35°C dry-bulb / 28°C wet-bulb outdoor; 27°C dry-bulb at 60% relative humidity indoor) for ships operating in tropical service. Details of the shipboard air-conditioning plant and ventilation design that delivers those conditions appear in the marine HVAC systems article and can be estimated with the HVAC accommodation cooling load calculator.

Standard A3.1 paragraph 5(e) requires that ships operating in latitudes where cold-weather heating is necessary carry adequate heating in all accommodation spaces. The same paragraph prohibits primary heating by open fire or any heating device whose exhaust is vented into the accommodation. Steam radiators connected to the main boiler circuit, hot-water fan coil units, and direct-expansion reverse-cycle splits all satisfy the requirement; unflued gas heaters do not.

Noise limits under SOLAS II-1/3-12 and the 2012 Noise Code

MLC 2006 does not itself publish noise limit numbers. Standard A3.1 paragraph 6(c) states that accommodation shall be insulated to protect seafarers from noise and vibration, and Regulation 3.1 paragraph 4 says the competent authority shall give consideration to the relevant ILO and IMO codes of practice. The operative instrument is the IMO Code on Noise Levels on Board Ships, adopted by Resolution MSC.337(91) on 30 November 2012 and made mandatory under SOLAS regulation II-1/3-12 for ships of 1,600 GT and above with keels laid on or after 1 July 2014.

The Code sets A-weighted continuous noise limits by space type:

The 60 dB(A) limit in sleeping rooms is the number that most frequently drives accommodation design changes on ships with aft accommodation blocks above the engine room. ISO 6954:2000 governs the vibration measurement methodology used in conjunction with the Noise Code; it specifies one-third octave band measurements from 1 Hz to 80 Hz and expresses the vibration environment as overall frequency-weighted RMS values. Ships that fail the noise criterion on delivery have sought relief through acoustic floating floors, mass-spring mounts under compressor units, and lagging of discharge pipes routed through accommodation decks. The cruise noise cabin calculator applies the Code’s sleeping-room limit to estimate compliance margins.

Mess rooms and galleys

Standard A3.1 paragraph 12 requires separate mess-room facilities for the officers and ratings, though the same paragraph permits a single mess for vessels with fewer than ten crew. Each mess room must be sized to accommodate all persons using it at any one time, or to accommodate all persons entitled to use it if the ship operates a staggered meal system. The standard provides no explicit m² per person figure for mess rooms, leaving that to flag-state implementation or national regulations. UK Merchant Shipping Notice MSN 1827(M) and similar documents typically set 1.0 to 1.2 m² per seat including serving and passage space.

Mess rooms must be adjacent to the galley or connected to it by a service hatch or passage, and they must be furnished with tables, seats, and refrigeration for food storage. Standard A3.1 paragraph 12(d) requires a pantry or a service counter in or immediately adjacent to each mess. The galley itself, its design standards, and the equipment that supports food preparation are covered in the marine galley equipment and provisions article.

Regulation 3.2: food and catering

Regulation 3.2, with Standard A3.2, governs what seafarers eat, not just where. Standard A3.2 paragraph 2 sets four obligations: (a) catering standards appropriate to the religious requirements and cultural practices of the seafarers; (b) food and water of appropriate quality, nutritional value, quantity, and variety; (c) a ship’s cook holding a qualification recognized by the flag state for vessels with a crew of ten or more; and (d) the cook not being required to undertake other duties while on catering duty.

The qualification requirement for the ship’s cook is binding for vessels carrying ten or more crew. MLC 2006 Guideline B3.2.2 encourages flag states to accept cook certificates issued by another MLC ratifying state. In practice, the Manila Amendments to the STCW Convention (2010) added a ship’s cook training standard to Section A-V/4, and most flag-state authorities now accept STCW V/4 certificates as satisfying the MLC 3.2 cook-qualification requirement.

Standard A3.2 paragraph 3 requires flag-state inspection of food and water quality at intervals not exceeding three years. Port-state control officers can also examine catering records, food storage, and water quality when they have reasonable grounds to do so during an MLC inspection.

Sanitary facilities

Standard A3.1 paragraph 11 specifies a ratio of one toilet, one washbasin, and one bath or shower per every six persons (or portion thereof) who do not have private sanitary facilities. The washing facilities must be accessible from the passageway, not from a sleeping room, unless they serve only that room. Hot and cold running fresh water is mandatory. On ships built after August 2013, the standard also requires that at least one toilet, one washbasin, and one shower be provided on or immediately below the bridge deck for the use of the officer of the watch.

The practical implication of the “per six persons” rule differs sharply between vessel sizes. A 20-person crew vessel with single-berth cabins but no en-suite bathrooms needs at least four toilet, washbasin, and shower sets in shared spaces (20 divided by 6, rounded up to 4). A vessel of the same size where all 20 berths have private en-suite rooms satisfies the ratio without any shared sanitary facility because paragraph 11(a) explicitly credits private facilities. Modern bulk carriers and container ships routinely provide en-suite bathrooms in officer cabins and shared but adjacent bathrooms (one per two cabins) for ratings, which exceeds the standard in most configurations.

Standard A3.1 paragraph 11(b) requires that laundry facilities be available to seafarers, including machines capable of washing and drying clothes, drying lines, and irons. The flag state implements this as a ship certification condition. Laundry connections to shipboard fresh water and drain systems are addressed in the marine domestic water systems article.

Hospital accommodation

Standard A3.1 paragraph 13 requires that every ship carrying 15 or more persons engaged on a voyage of more than three days carry a separate hospital accommodation space. The space must:

• be located so that it is easy to reach and so that occupants can receive suitable treatment in all sea conditions;
• have no sleeping berths in it other than the hospital berth(s);
• be equipped with a berth or berths, the number determined by the flag state but never fewer than one;
• be fitted with natural or mechanical ventilation separately from the general ventilation system, an artificial lighting source, a means of calling for assistance, and wash facilities;
• carry a medicine chest whose contents are determined by the flag state in consultation with medical authorities.

Standard A4.1 paragraph 4 requires that a medical log be kept and that telemedicine services be available to the ship’s captain or the person responsible for medical care. Most flag states satisfy this through ITU radio medical advice services or commercial medical assistance providers with satellite connectivity. The marine domestic water systems article covers the fresh water supply requirements for the hospital wash facilities.

Ships carrying fewer than 15 persons on shorter voyages must still carry a medicine chest and comply with flag-state first-aid regulations, but the dedicated hospital space is not required.

Recreational facilities

Standard A3.1 paragraph 17 requires all ships to provide recreational facilities, amenities, and services that are appropriate to the needs of the seafarers, taking account of the nature and duration of the voyage. For ships on voyages of more than 24 hours, the facilities must include a reading room or library, and for voyages of 72 hours or more on a ship carrying 15 or more crew, a recreation room separate from the mess room is expected. Guideline B3.1.11 expands on this, suggesting access to physical exercise equipment, films and television, games, and internet-connected communications at a reasonable cost.

Internet access became a de facto welfare standard before it became a formal one. The 2022 amendments to the MLC (entering force April 2024) inserted a new paragraph into Guideline B3.1.11 stating that member states should ensure that ships provide reasonable access to seafarer internet-based communication at a reasonable cost. This is still a guideline (B-level, not A-level), meaning it is not directly enforceable as a Standard, but port-state memoranda increasingly treat absence of any internet access as a relevant welfare concern during inspections.

Maritime Labour Certificate and DMLC

MLC 2006 Regulation 5.1.3 requires that ships of 500 GT and above engaged in international voyages carry a Maritime Labour Certificate (MLC) and a Declaration of Maritime Labour Compliance (DMLC). The MLC is issued by or on behalf of the flag state after a verification inspection. It is valid for five years, with an intermediate inspection required between the second and third anniversaries of issue. Any deficiency found at the intermediate inspection that is not corrected results in endorsement or withdrawal of the certificate.

The DMLC has two parts. Part I is a flag-state document listing the national laws, regulations, or other measures that implement each requirement in Titles 1 to 5. Part II is completed by the shipowner and describes how Part I is met on the specific ship, including the procedures for monitoring ongoing compliance. The DMLC Part II must be verified by a recognized organization (classification society) or directly by the flag-state authority. Together, the MLC and DMLC form the primary documentary evidence a port-state control officer examines when boarding. The port state control article explains the boarding procedure and the MLC inspection in the context of the broader Paris MOU and Tokyo MOU regimes.

A ship without a valid MLC certificate or DMLC can be detained in any port of a ratifying state regardless of whether the accommodation itself is compliant. The certificate is not simply a check on physical conditions; it certifies that the management system for ongoing compliance is in place. Surveyors boarding under the MLC are specifically authorized to inspect cabin conditions, look at food and water records, review rest-hour logs, and check the medicine chest.

Port-state control inspections under MLC Title 5

MLC Title 5 establishes the most systematized port-state control regime in the ILO’s history. Regulation 5.2.1 gives port-state control officers the authority to board any foreign ship in their port, inspect the MLC and DMLC, interview seafarers, and carry out on-board inspections if they have clear grounds for believing that conditions on board do not conform to MLC requirements. The right to interview without the master or officers present is a deliberate provision, included to address the power asymmetry between seafarers and employers on a vessel at sea.

Common accommodation-related grounds for more detailed inspection include reports from seafarers, evidence of inadequate maintenance in common areas, complaints about catering, or documentation of rest-hour violations. Port-state control officers use the MoU regional guidelines (the Paris MOU guidance for North European and Atlantic ports, the Tokyo MOU guidance for Pacific and Indian Ocean ports) which provide step-by-step inspection criteria for accommodation, food, sanitary facilities, hospital, and recreational facilities.

Regulation 5.2.1 paragraph 4 draws a threshold distinction between a deficiency and a detainable condition. A deficiency triggers an inspection report and a requirement to remedy within a defined period; it does not require the ship to remain in port. A condition amounts to grounds for detention when it “is clearly hazardous to the safety, health or security of seafarers.” The ILO’s guidelines for port-state control officers (2013) list worked examples of conditions that cross that threshold: sleeping accommodation with no effective ventilation in a hot-weather port, a medicine chest missing essential medications specified by flag-state regulation, catering water that fails basic potability tests, or sleeping rooms physically inaccessible to seafarers during an emergency. A single deficiency in one sanitary unit does not ordinarily reach the detainable threshold unless the crew-to-fixture ratio drops below the Standard A3.1 paragraph 11 floor across the whole vessel.

In practice, PSC officers boarding under the MLC framework coordinate with SOLAS boarding officers. A ship detained on MLC accommodation grounds in a Paris MOU port is entered into the THETIS database and its deficiency history is visible to other MOU member states. The accumulated deficiency record affects the ship’s risk score, which in turn determines the frequency and intensity of future inspections. Individual deficiency records from both Paris MOU and Tokyo MOU are publicly searchable and include the specific paragraph of Standard A3.1 that was breached.

Detention for accommodation deficiencies under the MLC is less frequent than detention for safety equipment failures under SOLAS. Still, both Paris MOU and Tokyo MOU annual reports show “living and working conditions” consistently among the top five deficiency categories by total deficiency count across all MLC inspections, reflecting that accommodation issues recur even on ships that pass SOLAS surveys without difficulty.

The flag state and flag of convenience article addresses how flag-state survey quality interacts with port-state control enforcement, and the classification society article covers the role of recognized organizations in carrying out MLC flag-state surveys on behalf of administrations.

Grandfathering for ships built before August 2013

Regulation 3.1 paragraph 2 is the grandfathering clause. It states that “for ships constructed before the date of entry into force of the Convention for the Member State concerned, the requirements for sleeping room and mess room areas set out in Standard A3.1, paragraphs 7(b), 13, and 14 shall be applied in accordance with the requirements for crew accommodation in the Accommodation of Crews Convention (Revised), 1949 (No. 92), and the Accommodation of Crews (Supplementary Provisions) Convention, 1970 (No. 133).”

In plain terms: a ship built and certificated under Conventions 92 and 133 before the flag state’s MLC ratification entered force retains those dimensions. Convention 92 set a floor of 3.75 m² for a single berth on ships of 1,000 GT and above, which is below the MLC 4.5 m² floor. The difference matters for ships built in the late 1990s and early 2000s under flag-state implementations of Convention 92 that were at the minimum.

The grandfathering does not extend to:

• Operational obligations in MLC Titles 1 and 2 (wages, contracts, hours of work and rest): all ships, all build dates.
• Medical care under Regulation 4.1: all ships, all build dates.
• Certification and port-state control under Title 5: all ships, all build dates.
• Any accommodation upgrade triggered by a “major conversion,” a term each flag state defines but which typically includes a change in function, a substantial extension, or structural work that takes the vessel to a new classification survey.

The practical implication is that a 2010-built bulk carrier on the flags of a state that ratified MLC in September 2013 retains its Convention 92 cabin dimensions, but the crew must have compliant contracts, rest-hour records, and medical care from the first day after ratification entry into force. Flag states that ratified MLC before August 2013, such as Bahamas (March 2008) and Panama (June 2009), had no ships in their fleet with a build-date shelter, because those fleets already had ships built after those ratification dates that fell fully under Convention 92 and 133 as flag-state-implemented.

On-board and on-shore complaint procedures

MLC 2006 Regulation 5.1.5 and Standard A5.1.5 require every ratifying state to ensure that its flagged ships carry an on-board complaint procedure for seafarers. The procedure must allow a seafarer to raise a complaint without prejudice, must specify to whom the complaint is first addressed (typically the master or department head), and must include a shipowner escalation path if the first level does not resolve the matter. Standard A5.1.5 paragraph 4 explicitly prohibits victimization of a seafarer for filing a complaint; any disciplinary action taken against a complainant within a defined period is presumed retaliatory unless the shipowner can demonstrate otherwise.

On-shore complaint channels run in parallel. Under Standard A5.2.2, a seafarer on a foreign ship in port can file a complaint directly with the port-state competent authority when the on-board procedure has failed or when the seafarer fears retaliation for using it. The port-state authority must investigate and, where it finds a substantiated deficiency, notify the flag state. Where the deficiency amounts to a clear hazard to safety or health, the port-state authority may act directly without waiting for the flag-state response. The ILO developed a standardized complaint form and guidance notes for port-state authorities in its 2013 document “MLC, 2006, Guidelines for Port State Control Officers,” paragraph 5.2.2.

In practice, many seafarers route complaints through the International Transport Workers’ Federation (ITF) affiliated union inspectors who board ships in port. ITF inspectors do not have MLC-authorized boarding powers, but they can submit complaints on behalf of seafarers to the competent port-state authority under the Standard A5.2.2 channel. Paris MOU and Tokyo MOU annual reports consistently show that seafarer-sourced complaints account for a material share of initiated more-detailed inspections, with “wages and financial security” and “seafarer employment agreements” as the most frequent subjects, followed by “accommodation and recreational facilities.”

MLC 2006 amendments and the 2022 revision cycle

The MLC Special Tripartite Committee (STC) convenes approximately every five years to review the Convention. The 2014 amendments (in force January 2017) addressed financial security for medical care and for seafarer abandonment. The 2016 amendments (in force December 2018) introduced significant additions: Standard A4.3 was amended to require that ships have policies and procedures to prevent harassment and bullying on board, consistent with the ILO/ICS joint guidance published in 2016 (“Guidance on Eliminating Shipboard Harassment and Bullying”). Those policies are now part of the occupational safety and health management system that flag states must verify when issuing the MLC certificate; a ship without a documented anti-harassment policy is in breach of Standard A4.3 as amended, and a port-state control officer may treat the absence as grounds for a more detailed inspection.

The 2018 amendments (in force October 2019) added financial security requirements for seafarer abandonment and personal injury. The 2022 amendments (adopted April 2022, in force April 2024) addressed internet access, seafarer employment agreements when ships are detained, and adjustments to the standard on repatriation. The internet-access provision, inserted into Guideline B3.1.11, states that member states should ensure ships provide reasonable access to seafarer internet-based communication at a reasonable cost; this wording was formally effective December 2024 under the agreed STC timeline. None of the 2022 amendments changed the dimensional requirements in Standard A3.1; the 203 cm headroom floor, the tonnage-banded floor areas, and the sanitary ratios remain as adopted in 2006.

The next STC review cycle will consider proposals including minimum cabin temperatures in cold-weather regions, light-level requirements, and whether the 4.5 m² single-berth minimum should be increased in line with modern newbuilding practice. As of 2026 these remain proposals, not adopted Standards.

Vibration exposure and ISO 6954

Vibration in crew accommodation is governed separately from noise. ISO 6954:2000, “Mechanical vibration: Guidelines for the measurement, reporting, and evaluation of vibration with regard to habitability on passenger and merchant ships,” sets the evaluation methodology. The standard expresses vibration in terms of overall frequency-weighted RMS acceleration values in the 1 Hz to 80 Hz band, reported separately for vertical and horizontal directions.

ISO 6954 does not set a single pass/fail limit; instead it defines three response zones. The upper limit of zone A, expressed as a peak value of 126 mm/s² (approximately 12.9 mm/s RMS at a typical crest factor), is the level above which the probability of adverse crew comments is high. Class society rules and many shipowner specifications use this as the design target for sleeping-room locations. Propeller-induced vibration at blade-passing frequency typically falls in the 5 to 20 Hz range where ISO 6954 weighting is at maximum; stern vibration surveys at sea trials check accommodation spaces directly above the propeller shaft and rudder trunk.

Classification society comfort-class notations

Several classification societies publish voluntary notation schemes that certify noise and vibration performance above the mandatory SOLAS/MLC floor. These notations matter commercially: passenger ship operators and some tanker owners seek them to differentiate vessels, and charterers writing specifications for long-term contracts sometimes require a comfort notation as a condition of charter.

DNV’s COMF notation is the most widely referenced. COMF(V) covers vibration; COMF(N) covers noise; COMF(C) covers climate (thermal comfort). Each is awarded at three levels – COMF(V)-1, COMF(V)-2, COMF(V)-3 – with progressively tighter limits. The COMF(V) limits in sleeping spaces at level 3, for example, are approximately 30% below the ISO 6954 zone-A upper limit. COMF(N) sleeping-room limits at level 3 run to around 55 dB(A), compared to the mandatory 60 dB(A) in MSC.337(91). DNV’s comfort class rules were first published under Det Norske Veritas in 1999 and were carried forward after the 2013 merger with Germanischer Lloyd.

Lloyd’s Register’s PCAC (Passenger Comfort, Acoustic and Vibration Class) notation applies a tiered system similarly. LR also publishes a Crew Comfort Class (CCC) notation specifically covering merchant vessels where passenger-grade acoustic treatment is not specified but crew habitability needs exceeding the MLC minimum are desired. Bureau Veritas offers its COMF notation under analogous criteria. American Bureau of Shipping has addressed comfort through the NOISE and VIBRATION notations in its Guide for Crew Habitability on Ships.

These notations require in-service measurements at defined loading and speed conditions. A ship can carry a comfort notation on its classification certificate simultaneously with its MLC certificate; the two documents speak to different standards and neither substitutes for the other. A vessel that exceeds a DNV COMF(N)-2 sleeping-room limit but still stays within the mandatory 60 dB(A) MSC.337(91) requirement is MLC-compliant but loses the voluntary notation endorsement at the next class survey.

Interaction with SOLAS and class rules

MLC 2006 accommodation requirements do not stand alone; they interlock with SOLAS construction requirements and class rules. SOLAS II-1/3-12 imports the MSC.337(91) Noise Code as mandatory, making flag-state accommodation survey and MLC certification mutually dependent on the noise measurement process. SOLAS II-2/Reg.9 requires that crew accommodation spaces be separated from machinery spaces by fire divisions rated to at least A-60, which constrains where accommodation can be placed relative to the engine room. The SOLAS Chapter II-1 article covers the structural context.

Classification societies typically fold MLC accommodation surveys into the class periodical survey cycle. Most major societies, including DNV, Lloyd’s Register, Bureau Veritas, and the American Bureau of Shipping, maintain their own accommodation checklists calibrated to Standard A3.1 paragraphs. A ship that satisfies class accommodation requirements on a given survey almost always satisfies the MLC standard, but class survey does not substitute for the flag-state MLC certification under Regulation 5.1.3; both must be current.

Practical compliance patterns

Surveyor reports and ITF fleet inspection data reveal consistent patterns in where vessels fall short of Standard A3.1. On dry bulk carriers and tankers built to the MLC minimum, the most common deficiencies are:

• Inadequate lighting in sleeping rooms (below 300 lux at the reading point, a figure recommended by Guideline B3.1.4)
• Mattresses that fail fire resistance criteria or show mold from inadequate ventilation
• Shared sanitary facilities with hot-water supply intermittent due to calorifier failures
• Mess rooms without adequate refrigerated storage, causing Standard A3.2 food quality concerns
• Noise levels in aft cabins on single-screw vessels exceeding the 60 dB(A) sleeping-room limit, particularly at heavy displacement

On older vessels operating under grandfathering, the most common issues are cabin areas below the 4.5 m² Standard A3.1 threshold that have not been correctly assessed as grandfathered under Convention 92, or cabins that were at the Convention 92 minimum but have been reduced by in-service modifications (fitted furniture, bunk additions) that were not surveyed.

The crew MLC work hours calculator and MLC rest hours calculator assist compliance monitoring for the Title 2 obligations that run alongside the accommodation standards.

Catering water systems and grey water

Standard A3.2 requires that drinking water be of appropriate quality. The standard does not prescribe a specific coliform limit or WHO guideline reference, leaving that to flag-state implementation; most flag states reference WHO Guidelines for Drinking-water Quality (4th edition, 2011). Fresh water storage, distribution, and treatment systems are shared between accommodation, the hospital, and the galley; the marine domestic water systems article covers storage sizing, pressure system design, and UV or chlorination treatment.

Grey water from showers, laundry, and wash basins is governed by MARPOL Annex IV in conjunction with the relevant port and coastal state regulations. The marine sewage and grey water treatment systems article covers the treatment plant options and the MARPOL Annex IV discharge conditions.

Seafarer wages and the accommodation cost deduction prohibition

Standard A3.1 paragraph 18 prohibits the shipowner from deducting any costs of compulsory accommodation services from seafarers’ wages. The MLC minimum wage, rest hours, and related financial obligations are tracked under seafarer MLC wages and minimum manning. The accommodation standard is part of a broader framework: a ship that has a valid Maritime Labour Certificate but pays below the ILO minimum wage is in breach of MLC Titles 2 and 5, regardless of the physical quality of its cabins.

Limitations

This article describes the MLC 2006 Standards as consolidated and amended through the 2022 revision cycle effective April 2024. Several constraints apply when using this information operationally:

• Flag-state implementation varies. MLC sets minimum standards; individual flag states may and do legislate higher requirements. The Marshall Islands Maritime Act, the Liberian Merchant Shipping Act, the UK Merchant Shipping Act, and similar instruments each translate MLC obligations into national law, and the differences in wording can affect dimensional requirements, survey timing, and enforcement priority.

• The grandfathering analysis depends on the specific vessel’s build date, the flag state’s MLC ratification date, and the earlier conventions the flag state had in force at ratification. No single article can substitute for a flag-state-specific legal analysis for a particular vessel.

• Noise measurement under MSC.337(91) requires in-service measurements at defined loading conditions. Measurements taken at sea trial or in port do not capture all operational noise sources, and many vessels that pass sea-trial measurements have post-delivery complaints from crew about noise levels under full cargo.

• ISO 6954 vibration limits are guidance values, not mandatory limits under MLC; a vessel that exceeds the ISO 6954 zone-A threshold in sleeping rooms is not automatically in MLC breach, but the condition is likely to surface as a port-state concern and will be cited in ITF fleet inspections.

• The 2022 MLC amendments on internet access are at Guideline level, not Standard level. Port-state control action for absence of internet access requires “clear grounds” and is discretionary, not automatic.

• The article does not cover naval vessels, fishing vessels below 24 m, traditionally built ships, vessels in internal waters only, or other categories explicitly exempted from MLC scope by Article II.

See also

• MLC 2006
• Marine HVAC Systems
• Marine Galley Equipment and Provisions
• Marine Domestic Water Systems
• Marine Sewage and Grey Water Treatment Systems
• Port State Control
• Flag State and Flag of Convenience
• Classification Society
• SOLAS Chapter II-1 Construction and Stability

Related calculators

• Accommodation Cabin Size Calculator
• Crew MLC Work Hours Calculator
• MLC Rest Hours Calculator
• Seafarer MLC Wages Calculator
• MLC Minimum Manning Calculator
• HVAC Accommodation Cooling Load Calculator
• Cruise Noise Cabin Calculator