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MGN 397 (M+F)

Guidelines for the Provision of Food and Fresh Water on Merchant Ships and Fishing Vessels

Notice to all Ship owners, Shipbuilders, Operators, Masters, Skippers, Officers and all Seafarers on merchant ships and fishing vessels

This Notice replaces Marine Guidance Note MGN 61 (M+F) and Merchant Shipping Notices 1214 and 1401


Where this document provides guidance on the law it should not be regarded as definitive. The way the law applies to any particular case can vary according to circumstances - for example, from vessel to vessel and you should consider seeking independent legal advice if you are unsure of your own legal position.


These Guidelines provide practical advice on the provision of food and water for all merchant ships and fishing vessels. They also take account of the relevant guidelines of the International Labour Organization Maritime Labour Convention 2006.

Key Points

  • All ships should provide free of charge food and drinking water of appropriate quality, nutritional value and quantity to meet the needs of those on board.
  • Food hygiene principles and the provision and maintenance of fresh water must be applied regardless of the age, size and type of vessel.
  • Bacterial contamination is the most serious risk to food and fresh water safety.
  • Those preparing or serving food must be properly trained and demonstrate a working knowledge of the principles and practices of food hygiene.
  • Prevention using a risk assessment and management approach is one of the most effective means of ensuring food and fresh water safety.

  1. Background: the legal framework

    1.1 The main relevant merchant shipping regulations are the

    Merchant Shipping (Provisions and Water) Regulations 1989

    Merchant Shipping (Crew Accommodation) Regulations 1997

    Merchant Shipping (Crew Accommodation) (Fishing Vessel) Regulations 1978

    Merchant Shipping (Crew Accommodation) (Fishing Vessels) (Amendment) Regulations 1998

    Merchant Shipping & Fishing Vessel (Health & Safety at Work) Regulations 1997

    Please note as a water treatment specialist we have only included 'Part 2. Fresh Water' In this document, for the full document please visit http://www.mcga.gov.uk/c4mca/mgn397.pdf

    1.2 There are also public health regulations that are relevant, including the

    • Food Hygiene Regulations 2006, as amended, and
    • Public Health (Ships) Regulations 1979 as amended

    1.3 For merchant ships and UK registered fishing vessels over 24m in length, the Provisions and Water Regulations specifically require the supply of provisions and water that:

    • are suitable in respect of quantity, nutritive value, quality and variety having regard to the size of the crew and the character and nature of the voyage;
    • do not contain anything which is likely to cause sickness or injury to health or which renders any provision or water unpalatable, and are otherwise fit for consumption.

    1.4 The Crew Accommodation Regulations for both merchant ships and fishing vessels 15 metres and over require galleys, storerooms, sanitary and cabin accommodation to be maintained in a clean and habitable condition and that all equipment and installations be maintained in good working order.

    1.5 The MCA's Code of Safe Working Practices for Merchant Seamen supports Merchant Shipping Regulations and gives additional guidance on standards expected on merchant ships. Detailed advice specific to galley operations is available in Chapter 14.

    1.6 The Maritime Labour Convention 2006 also covers standards for Food and Catering for merchant shipping (Title 3.2 of the Convention) and this guidance reflects its provisions.

  2. General Principles

    2.1 In providing food and drinking water on board ship, account should be taken of factors including the duration and nature of the voyage; the number of seafarers on board; and the quantity, nutritional value, quality and variety of the food. The religious requirements and cultural practices of the seafarers as they relate to food should also be taken in to account.

    2.2 For ships with a catering department, the organization and equipment should be such as to permit the provision to the seafarers of adequate, varied and nutritious meals prepared and served in hygienic conditions.

    2.3 Food hygiene principles must be applied regardless of the age, size and type of vessel. The information contained in this Notice provides a practical food hygiene guide which supports ILO standards and general food safety principles for the vast majority of vessels, such as general cargo vessels, where catering arrangements relate more to a domestic environment than a food business.

  3. Training

    3.1 Those with responsibility for catering should be properly trained or instructed for their positions and have an adequate knowledge of food and personal hygiene to ensure that food is stored, stock rotated, handled, cooked and served safely and that good practice is clearly applied. Ships' Cooks and other equivalent qualifications will include food hygiene training.

    3.2 Periodic assessments of the effectiveness of training or instructions should be made. Company and ship audits should be able to verify competency levels. If there is any evidence of poor hygiene practices, designated cooks or others working in the galley should receive refresher training or other appropriate food hygiene training.

    3.3 Catering staff should have an awareness of the potential problems associated with food allergy and intolerance and have a basic understanding of how to avoid cross contamination and of the importance of providing accurate information to the crew.

  4. Crew Information

    4.1 Information on food and water safety should be readily available to members of the crew and should be in a language that includes English and is clearly understood.

  5. Inspection and enforcement

    5.1 The Merchant Shipping (Provisions and Water) Regulations 1989 require the inspection at least once a week of the supplies of food and water by the master or his deputy together with a responsible member of the catering department.

    5.2 Ships are inspected by marine surveyors according to the MCA's inspection regime which provides for food safety and hygiene standards in accordance with the relevant merchant shipping legislation.

    5.3 Environmental or Port Health Officers enforce food safety standards and issue ship sanitation certificates as required by the International Health Regulations.

    5.4 A close liaison is maintained between local offices of respective organizations to avoid duplication of effort and to ensure that where inspections carried out by members of one organization reveal a situation that would clearly also be of concern to the other, appropriate actions under respective powers can be considered.

  6. More Detailed Advice

    6.1 Detailed guidance in this Notice is arranged as follows:

    Part 1 : Food safety and hygiene including advice on diet and nutrition

    Part 2 :Water, including its supply, storage and distribution and advice on maintenance of water systems.

More Information

Inspection Branch Maritime and Coastguard Agency Bay 2/22 Spring Place 105 Commercial Road Southampton SO15 1EG

Tel : +44 (0) 23 8032 9549 Fax : +44 (0) 23 8032 9104
e-mail: PSC.Headquarters@mcga.gov.uk

General Inquiries: infoline@mcga.gov.uk

MCA Website Address: www.mcga.gov.uk

File Ref: MS124/002/0057

Published: July 2009 Please note that all addresses and telephone numbers are correct at time of publishing

© Crown Copyright 2009

Safer Lives, Safer Ships, Cleaner Seas

Printed on material containing minimum 75% post-consumer waste paper

Part 2


This Part covers fresh water loading and supply arrangements, disinfection, storage, distribution systems and maintenance

  1. Introduction

    The Merchant Shipping (Crew Accommodation) Regulations 1997 and the Merchant Shipping (Crew Accommodation) (Fishing Vessels) Regulations 1975 require the supply of drinking and fresh water to be such as to prevent any risk of contamination. In addition the 1997 Regulations require the supply of hot, fresh water and cold drinking water to any sink, wash hand basin or other washing facility in a galley.

    Improperly managed water is an established infectious disease transmission route on ships. Outbreaks of illness have been associated with contaminated bunkered water, cross connections between potable and non-potable water, improper loading procedures, poor design and construction of potable water storage tanks and inadequate disinfection. Evidence from outbreaks indicates that sewage is one of the more common sources of the pathogens that cause waterborne disease outbreaks on ships.

    The most effective means of ensuring the safety of the fresh water supply is through the use of a risk assessment and management approach that covers the whole process from loading to delivery at the tap and includes a planned maintenance system. All of the information gathered should be used to develop a Fresh Water Safety Plan (FWSP), particularly for ships with a complex system, which could be incorporated into the ship's planned maintenance system. An FWSP should be based on the following format.

    • System assessment and hazard analysis (including an assessment of source water loaded on to the ship)

    • Management plan and control measures, (the selection and operation of appropriate treatment processes)

    • Monitoring and corrective action system in accordance with the Plan (the prevention of contamination/re-contamination during storage and distribution).

    Control measures (treatments) will be influenced by the quality of the source water. In the event of the potable water becoming unfit for human consumption then the tank(s) and distribution system should be drained, super-chlorinated and flushed in accordance with section 7 (Maintenance of water systems) below.

    In addition to the above the ship should consider requesting water samples from the supplier prior to bunkering.

  2. Fresh Water Loading and Supply Arrangements

    Freshwater obtained from shore mains supply or water barge should be transferred by a designated fresh water hose. Hoses should be durable, with a smooth, impervious lining, and equipped with fittings, including adapters, to permit connection to the shore potable water hydrants and filling connections to prevent their use for loading other liquids. Hoses should be

    • clearly marked (generally coloured blue)

    • stowed in a locker clear of the deck

    • drained and capped at both ends after use

    • flushed through and discharged to waste before loading.


    Often ships use quayside hoses, in which case a designated crewmember should ensure that such hoses are in good condition and that they are routinely disinfected, safely stowed and capped in a clean environment.

    Every potable water tank should have a filling line to which a hose can be attached. This line should not be cross-connected with any line of a non-potable water system. Each line should be clearly identified as such and painted blue with a screw cap or plug fastened by a short chain so that the cap does not touch the deck when hanging free

  3. Disinfection

    There should be no facility for by-passing primary automatic disinfection systems. Automatic disinfection systems should have a fail safe control arrangement with an audible/visual automatic alarm to prevent the passage of water in the event of any malfunction. The power supply required to operate the alarm should be independent of the disinfection unit power supply.

    3.1 Chlorination

    The UK generally accepts chlorine as a disinfectant which requires around 20 minutes contact time to react. It can be the case that shore mains water only contains low concentrations of free chlorine which may be further decreased within the ship environment. Although there is no requirement to do so and control measures will be influenced by the quality of the source water, it is considered good practice to add chlorine as a routine when loading fresh water to a level that produces a 0.2 mg/L (ppm) residual free chlorine or 1.0 mg/L (ppm) chloramine when chloraminated water is supplied. Chlorine should preferably be applied as a hypochlorite solution, using a commercial hypochlorinator designed for the purpose or by using an automatic chlorination unit in the ship's deck filling line. The concentration may also be achieved by the manual method using the formula contained in the "WHO's Guide to Ship Sanitation'. A commercial test kit should be used to check the free chlorine or chloramine levels.

    Some other treatments available include:

    3.2 Silver-coated filter candles

    These filters retain suspended matter and they have a bactericidal effect. Treatment is instantaneous without any addition of chemicals.

    3.3 Electro-Silver Ionization

    Electro-silver ionization may be used for the automatic disinfecting of fresh water produced on board ships. Units should be set up by the manufacturer to ensure a minimum concentration of 0.1ppm to be added to the water under maximum flow conditions. The minimum time required for silver to take effect is 4 hours after passing through the unit. This should ensure a maximum 0.08 ppm in the system

    3.4 Ultra-Violet Sterilization

    Although the sterilization process is instantaneous, ultra-violet sterilizer units have no dispersal or residual properties. For this reason UV treatment is generally used only as a supplementary system, fitted downstream of the water tank or supply pump. UV units may however be effective in certain cases where service lines are relatively short. They should be installed so that the direction of flow is vertical to keep deposits in the tubes to a minimum. The water should be continuously circulated in the system through the UV unit. There should be a means to measure the intensity of UV radiation. and a switch-off mechanism with an alarm should be fitted in the event of UV radiation being too weak. The performance of the tubes should be regularly monitored.

    3.5 Thermal Disinfection (Calefaction)

    Potable water supply lines contaminated with legionellae may not be reliably disinfected by means of chemical agents. Heating the flowing water throughout the distribution system (legionella tends to grow in dead legs and low-use areas) to a temperature of at least 60°C and maintaining this temperature for 30 minutes is another established method used to destroy the legionella bacteria. If the water temperature is increased the period for maintaining the temperature will be proportionately reduced. This method may be used in conjunction with chemical treatments.

  4. Fresh Water from Water Making Plant

    Sea water that is to be treated on ships should be taken from areas relatively free from pollution, including air pollution. Twenty miles from land is generally considered to be a safe distance but it may be in excess of the twenty miles in some cases. Judgment should be used based on a risk assessment which should include consideration of the possible effect that ship operations might have on the quality of the water intake.

    The seawater inlets (sea chests) should be located forward and if possible on the opposite side of the ship from all overboard waste water and ballast tanks discharge outlets. Sea water should pass through suitable filters before entering the water making equipment.

    The manufacturers' operating instructions should be clearly posted in the plant room and strictly followed.

    By-passes should not be installed around treatment units except where necessary as part of the treatment process. There should be an adequate store of spare replacement parts particularly for any vital or fragile parts. Distillation units should indicate low range salinity levels, operational temperature levels and have an automatic discharge to waste. They should also have an alarm with trip setting or equivalent.

    Any chemicals used in an injection system to a sea suction intended to prevent the growth of organisms in the ship's piping system serving water making plant should be suitable for that purpose.

    High pressure distillation and reverse osmosis plants are highly effective in removing micro­organisms and chemical constituents. They can therefore be employed as a single treatment so long as they remain effective. There is therefore a need for highly reliable on-line monitoring linked to rapid management intervention. They can however be combined with the application of a low level of residual chlorine or other equivalent disinfectant. Because low pressure evaporators operate at lower temperatures, this type of plant should be fitted with an automatic disinfecting unit, generally chlorine is used, before it is pumped to the storage tanks.

    Desalinated water effectively dematerializes the seawater which makes it corrosive with the potential to damage lines, tanks etc. Also the taste of desalinated water is bland, and may be considered unpalatable. Appropriate stabilizing and mineralizing chemicals treatments should therefore be applied before the water is passed into the storage tank.

  5. Filtration

    Filters should be used only where necessary as part of a purification system that includes disinfection. Terminal or tap filters often collect bacteria and accelerate its growth and for this reason their use should be discouraged unless they can be disinfected or replacement cartridges are used. Filters should be maintained or replaced according to manufacturers' instructions.

  6. Water Storage and Distribution Arrangements

    6.1 Potable water storage tanks

    Storage tanks should normally be sited above the inner bottom and independent of the hull and not adjacent to tanks containing oil. They should be sited and be of such dimensions that they are readily accessible to facilitate inspection, cleaning and coating.

    Tanks should be clearly marked "Potable Water". They should be used in regular rotation to avoid stagnation.

    Storage should normally never be less than a 2 day supply. Consideration should be given to the size of the ship's complement of officers and crew, the maximum number of passengers, the time and distance between ports of call and the availability of water suitable for treatment with facilities aboard. Storage may be decreased if the water supply can be supplemented by water produced by water making plants, but only to the amount that can be reliably supplied by the water making plant.

    Coatings systems other than cement should be specially developed for use in potable water tanks. Manufacturer's recommendations for application and drying or curing of the coating must be followed. All items that penetrate the tank, for example bolts, pipes, pipe flanges should be coated with the same product.

    6.2 Distribution Systems

    The freshwater distribution pumps should not be capable of being connected to any other service. The suction lines of the pumps should not be cross-connected with the piping or storage tank of any non-potable-water system. Lines should not be submerged in bilge water, or pass through tanks storing non-potable liquids. Overflows, vents and drains from tanks, and drains from the distribution system (including any treatment plant) should not be connected directly to sewage drains.

    Potable water piping should be painted or hatched blue. If the direction of flow is important, this shall be shown by means of an arrow pointing in the respective direction. Potable water outlets should be labelled POTABLE WATER. All non-potable outlets should be labelled UNFIT FOR DRINKING. If hot water piping and cold water piping run adjacent to one another, appropriate thermal insulation should be carried out.

    Calorifiers and pressure tanks should be fitted with efficient connections at the lowest point of the unit so that loose scale or sludge can be completely drained off after cleaning and maintenance. They should have adequate access to enable thorough cleaning.

    The design of the distribution system should provide maximum circulation, avoiding dead legs and optimum conditions for bacterial growth (15°C to 50°C). The risk increases where sections of the system are not kept in continuous use. To minimize the risk a ring main system with circulation pumps in hot and cold water lines should be considered for large scale demand such as passenger ships for example.

    Corrosion and scale inhibitors if used should be suitable for use in fresh water systems.

    6.3 Taps and Other Fixtures

    Fixtures should be resistant to the corrosive effects of salt water and saline atmosphere and fit for use with fresh water systems. They should be easy to clean and so designed to function easily and efficiently. Approved mixer taps should be fitted to showers and it is recommended that wash-hand basins should have hot and cold mixer taps.

  7. Maintenance of Water Systems

    All elements of the freshwater production, treatment and delivery system including filters, pumps, calorifiers, pressure tanks etc should be inspected, cleaned, flushed out, or items replaced where appropriate, according to the manufacturers instructions and the planned maintenance system. The following maintenance is recommended.

Health & Safety

Adequate care should be taken when handling chemicals or biological agents, for example chemicals, corrosion inhibitors, filters etc. Suitable risk assessments and control measures should be applied.

The rules for classification and construction of seagoing ships stated by the relevant classification societies should be observed. Reference should also be made to the following British Standards in relation to sanitary design and construction of ship water supplies.

  • ISO 15748-1: 2002 - Ships and marine technology - Potable water supply on ships and marine structures - Part 1: Planning and design.

  • ISO 15748-2: 2002 - Ships and marine technology - Potable water supply on ships and marine structures - Part 2: Method of calculation.

The WHO Guide to Ship Sanitation

This Guide provides advice on a number of topics, including the management of swimming pools and spas on board ships, and is available on the internet as a draft at


The HSE Approved Code of Practice and Guidance for the Control of Legionella Bacteria in Water Systems

This guide provides practical advice for the control of legionella bacteria in any undertaking involving a work activity and to premises controlled in connection with a trade, business or other undertaking where there is a reasonably foreseeable risk of exposure to legionella bacteria. Although the Code of Practice is not specific to a marine environment, it does provide advice about prevention or controlling exposure to the bacteria and treatment and control programs. The Code of Practice may be obtained from the Health and Safety Executive ( www.hse.gov.uk )