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MODULE 2K-Carriage of Dangerous Chemicals in Bulk



The regulation governing the carriage of chemicals by ship is contained in the International Convention for the Safety of Life Sea (SOLAS) and the International Convention for the Prevention of Marine Pollution from Ship, as modified by the protocol of 1978 relating thereto (MARPOL 73/78).

The regulations cover chemicals carried in bulk, on chemical tankers, and chemicals carried in packaged form.

Regulations covering chemicals carried in bulk
Transport of vegetable oils
Chemicals carried in packaged form
Liability and Compensation for Damage in Connection with the Carriage of Hazardous and Noxious Substances
Preparedness and response – dealing with pollution incidents involving chemicals

Chemicals carried in bulk
Carriage of chemicals in bulk is covered by regulation in SOLAS Chapter VII – Carriage of dangerous goods and MARPOL Annex II – Regulations for the Control of pollution by Noxious Liquid Substances in Bulk.

Both Conventions require chemical tankers built after 1 July 1986 to comply with the international Bulk Chemical Code ( IBC Code), which gives international standards for the safe transport by sea of the bulk of liquid dangerous chemicals, by prescribing the design and construction standards of the ship involved in such transport and the equipment they should carry so as to minimize the risks to the ship, its crew and to the environment, having regard to the nature the products carried.

The basic philosophy is one of the ship types related to the hazards of products covered by the Codes. Each of the products may have one or more hazard properties which include flammability, toxicity, corrosivity, and reactivity.

The IBC Code lists chemicals and their hazards and gives both the ship type required to carry that product as well as the environmental hazard rating.

Chemical tankers constructed before 1 July 1986 should comply with the requirements of the Code for the Construction and Equipment of Ship Carrying Dangerous Chemicals in Bulk ( BCH Code) – the predecessor of the IBC Code.

As a result of the hazard evaluation process and the categorization system, vegetable oils that were previously categorized as being unrestricted are now required to be carried in chemical tankers. The annex includes, under regulation 4 Exemptions, a provision for an Administration to exempt ships certified to carry individually identified vegetable oils, subject to certain provisions relating to the location of the cargo tanks carrying the identified vegetable oil.

Consequential amendments to the IBC Code.

Consequential amendments to the International Bulk Chemical Code (IBC Code) have been adopted, reflecting the changes to MARPOL Annex II. The amendments incorporate revisions to the categorization of certain products relating to the properties as potential marine pollutants as well as revisions to ship type and carriage requirements following their evaluation by the Evaluation of Hazardous Substances Working Group.

Ships constructed after 1986 carrying substances identified in chapter 17 of the IBC Code must follow the requirements for the design, construction, equipment, and operation of ships contained in the Code.

Preparedness and response- dealing with pollution incidents involving chemicals
The 2000 protocol on Preparedness, Response, and Co-operation to pollution Incidents by Hazardous and Noxious Substances, 2000 (HNS Protocol) is based on the International Convention on Oil Pollution Preparedness, Response and Co-operation (OPRC), WHICH WAS ADOPTED IN November 1990 and is designed to help Governments combat major oil pollution incidents.

The convention and Protocol are designed to facilitate international cooperation and mutual assistance in preparing for and responding to a major oil pollution incident and encourage States to develop and maintain an adequate capacity to deal with pollution emergencies.

Classification – Physics and Chemistry
(Part 2 of the Code)


The purpose of this training module is to give sea-going and shore personnel involved in handling dangerous goods a basic knowledge of chemistry so that they are able to understand the terms used in the IMDG Code, BCH, IBC, CODE, and to appreciate the hazards associated with the dangerous good they are dealing with.

It is not the intention of the module to turn non-chemist into chemists and it must be stressed at the outset that expert advice must always be sought if there is any doubt.

One area of confusion that potentially can have disastrous results is in the pronunciation and writing of chemical names some of which may be difficult to pronounce correctly e.g.

“isocyanatobenzotrifluorides” may be easily confused during an emergency telephone call e.g. thionyl chloride and vinyl chloride.

Also, manes for the same chemical will often be different in different languages. To avoid misunderstanding, the United Nation Number given in column 1 of the DGL must always additionally be quoted, preceded by the letter “UN!” UN Numbers are only assigned to substances and articles which meet the classification criteria (see part 7)

Basic terms
What are physics and chemistry?

Physics is the study of the basic laws that govern our universe, including the forces that exist between objects and the interrelationship between objects, and the interrelationship between energy and matter.

Chemistry is defined as the science of elements and compounds and their laws of combination and behavior under various conditions. For study purposes, chemistry is divided into a number of major branches including physicals, inorganic, and polymer chemistry.

Physicals chemistry
This branch of chemistry is concerned with the effect of a chemical’s structure on its physical properties such as shape, color, odor, solubility, melting point, etc.

Organic Chemistry
This is the chemistry of carbon compounds apart from some of the most simple ones such as carbon monoxide, carbon dioxide, and carbonates. There are over a million organic substances, some natural, some man-made (synthetic), and some both, with new ones being found every day. Many substances are familiar_ sugar and crude oil, which are produced naturally, plastics such as polyethylene, which are produced synthetically, and alcohol, which can be made through both natural fermentation or synthesis, are examples of organic substances. Our organs and tissues are composed of organic compounds including carbohydrates, proteins, and fats. All living things are organic but not all organic substances are not found in living organisms.

Inorganic chemistry
This branch of chemistry is devoted to those substances which are not considered to be organic. Many of these are derived from minerals: iron ore and common salt are inorganic naturally occurring substances, as is water. They all have a characteristic chemical composition.

Polymer chemistry
This is really a sub-branch of organic chemistry but is so important that it is treated as a specialized subject. It the study of large or macromolecules which consist of repeating units of small molecules ( monomers). These may be naturally occurring, such as proteins, or manufactured synthetically, such as polyethylene.

These are the basic building block blocks from which all chemical structures are made. They cannot be broken down into simpler substances and are composed of identical atoms which are the smallest particles of an element that can chemically exist.

If the element iron and sulfur are blended together in powder form, then a mixture is formed. The two components retain their individual chemical and physical characteristic and will separate the metallic iron from the sulfur.

Mixtures may be either solid, such as gunpowder (carbon, sulfur, and saltpeter), liquid ( whisky and water), solid/liquid ( sugar in tea), or gaseous such as air (oxygen and nitrogen). Each component within the mixture is called a constituent.

If the mixture of iron and sulfur powders is heated together their atoms combine to form molecules ( fundamental units) of a new substance called a chemical compound, in this instance iron or ferrous sulfide.

A material is defined as having some general properties but these may vary depending upon the composition. For example, wood has some general properties that we all recognize but different kinds of wood have different colors and textures.

The IMDG Code refers to the term “substance”. This is a generic term covering chemicals the chemical composition of which does not vary significantly from one sample to another. Many substances are compounds, some are elements. Examples of substances are common salt (Sodium chloride), iron, and cane sugar.

The IMDS Code also refers to the term “article”. An article is a device that contains dangerous substances or a mixture of substances. Examples of articles are fireworks, aerosols, lighters bombs, etc.

Physical Chemistry
Physical states of matter
Matter exists in three states, solid, liquid, and gas. The physical state of many substances will vary depending upon the temperature and pressure applied to them.

Many solids such as common salt have a regular shape and are crystalline ( the atoms or molecules composing the substances are arranged in a regular pattern). Solids, which have no particular structure, are said to be amorphous.

Glass, rubber, and many plastics are amorphous. Some solids take water from the air and become damp. These are called hygroscopic. Common salt is an example of a hygroscopic solid. Some crystals actually dissolve in the water from the atmosphere to become concentrated solutions. Such solids are called deliquescent. It is difficult to compress solids.

Liquids have a definite mass and volume but no shape; they take up the shape of the container into which they are poured. Some liquids, like water, flow easily and are said to be mobile whilst others like treacle are said to be viscous.

Gases, like air, have a definite mass but no defined volume and will expand to fill the volume of the containment vessel. Gases are much less dense than solids or liquids and whilst some gases like chlorine are heavier than air, others like hydrogen are lighter than air. Gases are easily compressed and are available in pressure-resistant gas cylinders.

Physical properties
Chemicals are identified and characterized by their properties. Physical properties are used to assist in the classification of substances and articles within the Code and some important physical properties are also specified in the Code on the individual schedules.

Boling point
This is the temperature at which a liquid boils and begins to turn into a vapor. The boiling point will vary depending on the pressure applied.

Vapour pressure
All solids and liquids give off vapor consisting of atoms or molecules of the substance that have evaporated from the surface. The pressure that the vapor exerts under specified conditions is known as vapor pressure.

Vapour pressure increases with temperature and a liquid boils when its vapor pressure is equal to the atmospheric

This is the lowest temperature at which a volatile liquid gives off sufficient vapor to form a combustible liquid in air and in the presence of a naked flame gives a momentary flash but not a sustained fire under controlled conditions. It is an indication of the flammability of a substance.

Autoignition point
This is the temperature to which a liquid must be raised to cause a sustained fire or explosion when touched by a flame or hot object by the heat generated during the reaction or by friction. There is no relationship between flashpoint and ignition temperature.

Explosive limits
This is the percentage by volume vapor/air concentration of a substance that is ignitable.

Below the lower explosive limit ( LEL), the mixture is too “lean” to ignite, and above the upper explosive limit (UEL) the mixture is too rich. Schedules for flammable gases and liquids give the explosive limits for each substance.

Melting point
The melting point is the lowest temperature at which a solid will change into a liquid when heated e.g. ice turning to water.

The density of a sample of a substance is determined by dividing its mass by the volume it occupies. The resulting number is expressed as kilograms per cubic meter (kg/m3): the higher the number the more dense and heavy the substances.

When a solid or a gas ( a “solute”) dissolves in a liquid ( a “solvent”) a homogeneous mixture or solution is formed. Eventually, as more and more solute is added, the solution cannot dissolve anymore and is said to be saturated.

Many substances have a characteristic smell which may be the first indication of product escape. Any unusual odor should be treated as a warning and appropriate emergency action taken.

Hazardous chemicals and chemical reactions

All chemicals are to a greater or lesser extent hazardous to human health or to the environment. An iron bar dropped onto somebody’s head can maim or kill and even water can, under certain circumstances, be highly dangerous: probably more people have died by drowning than from exposure to any other chemical. However the United

Nations Committee of Experts on the Transport of Dangerous Goods have recognized that certain families or classes of substances and articles present particular and significant hazards from which the general public and those involved in their transport need to be protected.

More recently, IMO has also recognized that some substances, if accidentally released into the sea, will pollute the marine environment.

For convenience, the UN has divided these families of hazardous substances and articles into nine classes based on the type of hazard that they represent and criteria have been developed to enable sciences-based decisions to be made on the assignment of substances or articles to these classes. Basic knowledge of the chemistry of these families will assist in understanding the hazards they present.

Chemical hazard classes
Explosives (class 1)

Chemical explosions are usually caused by the rapid burning of a substance or mixture of substances in the presence of oxygen in the air (“deflagration”). The rapidly expanding gaseous products of this reaction cause damage by the propulsion of fragments of its container and other nearby material at high velocity and also by disturbance of the surrounding air (“blast”)

Explosives may be classified in a number of different ways:

• Primary and secondary explosives
A primary explosive is easily initiated: a secondary explosive requires a primary explosive for initiation. When initiated, tends to be more powerful. An example of a primary explosive is mercury fulminate. TNT is a secondary explosive whilst nitroglycerine has the initiation properties of a primary explosive and the power of a secondary explosive, hence the problems in handling this substance.

• High and low explosive
A high explosive such as nitro-glycerine will burn at such a rate that detonation occurs.

A low explosive such as gunpowder will not detonate. In detonation, a shock wave is generated which provides the energy not only to initiate the oxidation reaction but also to cause much more damage to the surroundings.

• The UN system
Explosives are classified within class 1 into six sub-divisions depending upon the type of explosive hazard (mass, projection, fire) and how sensitive the explosive is to initiation. For stowage purposes, explosives are also assigned to one of 13 compatibility groups. The combination of class, hazard division, and compatibility group is known as the hazard classification code which provides the key to identifying the provisions for safe storage and transport of explosive substances and articles assigned to the class.

Gases (class 2)
The IMDG Code defines a gas as a substance that has a vapor pressure greater than 300 kPa at 50°C or is completely gaseous at 20 C at atmospheric pressure.

Gases are stored and transported in one of four states:
♦ Compressed
♦ Liquefied
♦ Refrigerated liquefied
♦ In solution

Flammable liquids (class 3)
This class comprises liquids that have a flashpoint of 61 C c.c. or BELOW. Also included is any substance that is transported as a liquid at an elevated temperature at or above its flashpoint even if the flashpoint is above 61 C.

This class is composed almost entirely of liquids that are organic and the major hazard is the potential for their vapors to catch fire. Fire is the result of a chemical oxidation reaction involving three components:

1. A fuel
2. Oxygen (normally air)
3. A source of ignition

Flammable solids (class4)
This class comprises both inorganic and organic substances and is divided into three classes:

Flammable solids

This class includes:
• Readily combustible solids which if ignited can rapidly spread the resulting fire ( e.g) celluloid);
• Solids that may catch fire through friction can produce sufficient heat energy to ignite the substance (e.g. matches);
• Self-reactive solids and liquids and substances related to them. These are thermally unstable molecules that if heated will undergo a strongly exothermic decomposition reaction and some will burn vigorously.

Typical self-reactive substances contain nitrogen. Some self-reactive substances need to be temperature controlled during storage and transport;

• Desensitized explosives. These are explosives that are wetted with water or alcohol or diluted with other substances to suppress their explosive properties (e.g. mixtures containing between 2% and 10% nitroglycerine)

Substances liable to spontaneous combustion

1. Pyrophoric substances. These are substances (including mixtures and solutions) that even in small quantities will spontaneously ignite due to the rate of heat produced during the reaction with oxygen in the air exceeding the rate at which heat can be removed.

The overall effect is that the substance is raised to its auto-ignition temperature and thus catches fire.

Ignition occurs within five minutes of exposure. Typical examples of spontaneously combustible substances are some finely divided metal powders and metal catalysts.

2. Self-heating substances. These are substances that will only auto-ignite when stored for long periods of time (hours or days) in large (kg) amounts. Carbon powder and some vegetable fibers are liable to self-heating and are therefore classified as class 4.2.

Substances that, in contact with water, emit flammable gases (water-reactive)

Many of the substances involved are inorganic, including the metals cesium, lithium, potassium, and sodium, which form part of the alkali metal family, and some of their compounds. Some compounds of alkaline earth metals (calcium, lithium, magnesium, and strontium) are also water-reactive.

Oxidizing substances and organic peroxides (class 5)
Class 5 is divided into two:

Oxidizing substances
This class contains mainly inorganic compounds which have in common their ability during thermal decomposition to liberate oxygen contained within the molecule, which is then available to reach with other substances to form oxides. This process is called oxidation.

Organic peroxides
These compounds are related to the oxidizer hydrogen peroxide (H2O2) but one or both hydrogen atoms have been replaced by organic molecules. The resulting compounds are not only very strong oxidizers but many are thermally unstable some even at normal transport temperatures. Decomposition is initiated not only by temperature rise but sometimes by the presence of impurities.

Toxic and infectious substances (class 6) Toxic substances
Toxicology is the science of poisons and their effects on the body. Substances (both inorganic and organic) and articles assigned to class 6.1 are either known from experience to cause death or serious injury to humans by poisoning or, based on the results of testing the chemical on animals under strictly controlled conditions, are strongly suspected of causing harm to human health.

Radioactive material (class 7)
As mentioned in 6.2, atoms are composed of protons, neutrons, and electrons. Not all atoms in the same element have the same atomic mass because a few have a different number of neutrons. These are called isotopes or nuclides.

If the number of neutrons greatly exceeds the number of protons, as is common in heavy elements like uranium, radium, and thorium, the isotopes become unstable and eject particles from their nuclei to make them more stable.

These are called radioactive isotopes, radioisotopes, or radionuclides because the particles ejected can be detected using a Geiger counter. Two types of particles are emitted, alpha particles, which only travel a few centimeters in air, and beta particles, which may travel several meters.

They are often accompanied by energy in the form of gamma radiation. As a radioactive element decays a new element is formed which may also decay, and the process is repeated until a stable isotope is reached.

Corrosive (class 8)
This class comprises both organic and inorganic substances and articles which contain them.

All have the common property of causing damage to living tissue such as burns to skin, eyes, and mucous membranes and/or corrosion to the metal structures of the ship.

Miscellaneous dangerous substances and articles (class 9)
Substances and articles in this class do not meet the criteria for the other eight classes but nevertheless are considered sufficiently dangerous to warrant inclusion in the Code. This class includes substances likely to cause cancer (carcinogens) after even a single exposure ( asbestos, PCBs), irritants and allergens (benzaldehyde, castor beans), fire risk (substances carried at elevated temperatures), asphyxiants (dry ice, containers under fumigation) and environmentally hazardous substances (marine pollutants).

Classification- The System as Used by IMO
Part 2 and chapter 3.1 of the Code
United Nations Classes

The purpose of the United Nations dangerous goods classification system is twofold: firstly, to draw out boundary lines to determine which goods are dangerous and which goods are not dangerous in the transport environment: secondly, to show in broad terms what kind(s) of danger are to be found in a particular substance or article. There are a series of standard tests for deciding if a substance or article presents risks that make it dangerous to transport.

Dangerous goods are split into nine broad groups or classes dependent upon the major kind of danger that the substance presents; other risks may be present in a product and these are known as sub-risks or secondary risks whilst the main risk is referred to as the class risk.

Some classes are further split into divisions that categorize risk more finely. Each class or division has a diamond-shaped label assigned to it; these have broadly universal acceptance by all transport controls. The nine US classes and divisions of dangerous goods are:

1. Explosives

2. Gases
2.1 – Flammable gases
2.2 – Non-flammable, nontoxic gases
2.3 – Toxic gases

3. Flammable liquids

4. Other flammable substances
4.1- Flammable solids
4.2-Spontaneously combustible substances
4.3- Water-reactive substances

5 Oxidizer and organic peroxides
5.1 – Oxidizers
5.2- Organic peroxides

6 Toxic and infectious substances
6.1- Toxic substances
6.2- Infectious substances

7 Radioactive materials

8 Corrosives

9 Miscellaneous items.

Dangerous g Ship arrangements

Cargo segregation

  • Tanks containing cargo or residues of cargo subject to the Code shall be segregated from the accommodation, service, and machinery spaces and from drinking water and stores for human consumption by means of a cofferdam, void space, cargo pump-room, pump-room, empty tank, oil fuel tank or other similar space.
  • Cargo piping shall not pass through any accommodation, service, or machinery space other than cargo pump-rooms or pump-rooms.
  • Cargoes, residues of cargoes, or mixtures containing cargoes, which react in a hazardous manner with other cargoes, residues, or mixtures, shall:
    .1 be segregated from such other cargoes by means of a cofferdam, void space, cargo pump-room, pump-room, empty tank, or tank containing a mutually compatible cargo;
    .2 have separate pumping and piping systems which shall not pass through other cargo tanks containing such cargoes unless encased in a tunnel; and
    .3 have separate tank venting systems.
  • If cargo piping systems or cargo ventilation systems are to be separated. This separation may be achieved by the use of design or operational methods. Operational methods shall not be used within a cargo tank and shall consist of one of the following types:
    .1 removing spool pieces or valves and blanking the pipe ends;
    .2 arrangement of two spectacle flanges in series, with provisions for detecting leakage into the pipe between the two spectacle flanges.
  • Cargoes subject to the Code shall not be carried in either the fore or aft peak tank.
    1.2 Accommodation, service and machinery spaces, and control stations

No accommodation or service spaces or control stations shall be located within the cargo area except over a cargo pump-room recess or pump-room recess that complies with SOLAS regulations II-2/4.5.1 to and no cargo or slop tank shall be aft of the forward end of any accommodation.

  • In order to guard against the danger of hazardous vapors, due consideration shall be given to the location of air intakes and openings into accommodation, service and machinery spaces, and control stations in relation to cargo piping and cargo vent systems.
  • Access to forecastle spaces containing sources of ignition may be permitted through doors facing the cargo area provided the doors are located outside hazardous areas.
  • Cargo pump-rooms
  • Cargo pump-rooms shall be so arranged as to ensure:

1. unrestricted passage at all times from any ladder platform and from the floor; and

2 unrestricted access to all valves necessary for cargo handling for a person wearing the required personnel protective equipment.

  • Permanent arrangements shall be made for hoisting an injured person with a rescue line while avoiding any projecting obstacles.
  • Guard railings shall be installed on all ladders and platforms.
  • Normal access ladders shall not be fitted vertically and shall incorporate platforms at suitable intervals.
  • Means shall be provided to deal with drainage and any possible leakage from cargo pumps and valves in cargo pump rooms. The bilge system serving the cargo pump room shall be operable from outside the cargo pump room. One or more slop tanks for storage of contaminated bilge water or tank washings shall be provided. A shore connection with a standard coupling or other facilities shall be provided for transferring contaminated liquids to onshore reception facilities.
  • Pump discharge pressure gauges shall be provided outside the cargo pump room.
  • Where machinery is driven by shafting passing through a bulkhead or deck, gastight seals with efficient lubrication or other means of ensuring the permanence of the gas seal shall be fitted in way of the bulkhead or deck.
  • Access to spaces in the cargo area
  • Access to cofferdams, ballast tanks, cargo tanks, and other spaces in the cargo area shall be direct from the open deck and such as to ensure their complete inspection. Access to double-bottom spaces may be through a cargo pump room, pump room, deep cofferdam, pipe tunnel, or similar compartments, subject to consideration of ventilation aspects.
  • For access through horizontal openings, hatches, or manholes, the dimensions shall be sufficient to allow a person wearing a self-contained air-breathing apparatus and protective equipment to ascend or descend any ladder without obstruction and also to provide a clear opening to facilitate the hoisting of an injured person from the bottom of the space. The minimum clear opening shall be not less than 600 mm by 600 mm.
  • For access through vertical openings, or manholes providing passage through the length and breadth of the space, the minimum clear opening shall be not less than 600 mm by 800 mm at a height of not more than 600 mm from the bottom shell plating unless gratings or other footholds are provided.
  • Bilge and ballast arrangements
  • Pumps, ballast lines, vent lines, and other similar equipment serving permanent ballast tanks shall be independent of similar equipment serving cargo tanks and of cargo tanks themselves. Discharge arrangements for permanent ballast tanks sited immediately adjacent to cargo tanks shall be outside machinery spaces and accommodation spaces. Filling arrangements may be in the machinery spaces provided that such arrangements ensure filling from tank deck level and non-return valves are fitted.
  • Filling of ballast in cargo tanks may be arranged from deck level by pumps serving permanent ballast tanks, provided that the filling line has no permanent connection to cargo tanks or piping and that non-return valves are fitted.
  • Bilge pumping arrangements for cargo pump-rooms, pump-rooms, void spaces, slop tanks, double-bottom tanks, and similar spaces shall be situated entirely within the cargo area except for void spaces, double-bottom tanks, and ballast tanks where such spaces are separated from tanks containing cargo or residues of cargo by a double bulkhead.
  • Bow or stern loading and unloading arrangements
  • Cargo piping may be fitted to permit bow or stern loading and unloading. Portable arrangements shall not be
  • Bow or stern loading and unloading lines shall not be used for the transfer of products required to be carried in type 1 ships. Bow and stern loading and unloading lines shall not be used for the transfer of cargo emitting toxic vapors required to comply with 15.12.1 unless specifically approved by the Administration.
  • In addition to 5.1, the following provisions apply:

.1 The piping outside the cargo area shall be fitted at least 760 mm inboard on the open deck. Such piping shall be clearly identified and fitted with a shutoff valve at its connection to the cargo piping system within the cargo area.

At this location, it shall also be capable of being separated by means of a removable spool piece and blank flanges when not in use.

.2 The shore connection shall be fitted with a shutoff valve and a blank flange.

.3 The piping shall be full-penetration butt-welded, and fully radiographed. Flange connections in the piping shall only be permitted within the cargo area and at the shore connection.

.4 Spray shields shall be provided at the connections specified in as well as collecting trays of sufficient capacity, with means for the disposal of drainage.

.5 The piping shall be self-draining to the cargo area and preferably into a cargo tank. Alternative arrangements for draining the piping may be accepted by the Administration.

.6 Arrangements shall be made to allow such piping to be purged after use and maintained gas-safe when not in use.

The vent pipes connected with the purge shall be located in the cargo area. The relevant connections to the piping shall be provided with a shutoff valve and blank flange.

  • Entrances, air inlets, and openings to accommodation, service and machinery spaces, and control stations shall not face the cargo shore-connection location of bow or stern loading and unloading arrangements. They shall be located on the outboard side of the superstructure or deck-house at a distance of at least 4% of the length of the ship but not less than 3 m from the end of the house facing the cargo shore-connection location of the bow or stern loading and unloading arrangements. This distance, however, need not exceed 5 m. Side scuttles facing the shore connection location and on the sides of the superstructure or deckhouse within the distance mentioned above shall be of the fixed (non-opening) type. In addition, during the use of the bow or stern loading and unloading arrangements, all doors, ports, and other openings on the corresponding superstructure or deck-house side shall be kept closed. Where, in the case of small ships, compliance with 3.2.3 and this paragraph is not possible, the Administration may approve relaxations from the above requirements.
  • Air pipes and other openings to enclosed spaces not listed in 3.7.4 shall be shielded from any spray which may come from a burst hose or connection.
  • Escape routes shall not terminate within the coamings required by 3.7.7 or within a distance of 3 m beyond the coamings.
  • Continuous coamings of suitable height shall be fitted to keep any spills on deck and away from the accommodation and service areas.
  • Means of communication between the cargo control station and the cargo shore-connection location shall be provided and certified safe, if necessary. Provision shall be made for the remote shutdown of cargo pumps from the cargo shore-connection location

Cargo containment


  • “Independent tank” means a cargo-containment envelope, which is not contiguous with, or part of, the hull structure. An independent tank is built and installed so as to eliminate whenever possible (or in any event to minimize) it’s stressing as a result of stressing or motion of the adjacent hull structure. An independent tank is not essential to the structural completeness of the ship’s hull.
  • “Integral tank” means a cargo-containment envelope that forms part of the ship’s hull and which may be stressed in the same manner and by the same loads which stresses the contiguous hull structure and which is normally essential to the structural completeness of the ship’s hull.
  • “Gravity tank” means a tank having a design pressure not greater than 0.07 MPa gauge at the top of the tank.

A gravity tank may be independent or integral. A gravity tank shall be constructed and tested according to recognized standards, taking into account the temperature of carriage and relative density of the cargo.

  • “Pressure tank” means a tank having a design pressure greater than 0.07 MPa gauge. A pressure tank shall be an independent tank and shall be of a configuration permitting the applicati1: independent tank (4.1.1)

Materials of construction, protective linings, and coatings

  • Structural materials used for tank construction, together with associated piping, pumps, valves, vents and their jointing materials, shall be suitable at the temperature and pressure for the cargo to be carried in accordance with recognized standards. Steel is assumed to be the normal material for construction.
  • The shipyard is responsible for providing compatibility information to the ship operator and/or master. This must be done in a timely manner before delivery of the ship or on completion of a relevant modification of the material of construction.
  • Where applicable, the following should be taken into account in selecting the material of construction:
    .1 notch ductility at the operating temperature;
    .2 corrosive effect of the cargo; and
    .3 possibility of hazardous reactions between the cargo and the material of construction.
  • The shipper of the cargo is responsible for providing compatibility information to the ship operator and/or master. This must be done in a timely manner before the transportation of the product. The cargo shall be compatible with all materials of construction such that:

.1 no damage to the integrity of the materials of construction is incurred; and/or
.2 no hazardous, or potentially hazardous reaction is created.

  • When a product is submitted to IMO for evaluation, and where the compatibility of the product with materials referred to in paragraph 3.1 renders special requirements, the BLG Product Data Reporting form shall provide information on the required materials of construction. These requirements shall be reflected in chapter 15 and consequentially be referred to in column o of chapter 17. The reporting form shall also indicate if no special requirements are necessary. The producer of the product is responsible for providing the correct information.

Cargo temperature control

  • When provided, any cargo heating or cooling systems shall be constructed, fitted, and tested to the satisfaction of the Administration. Materials used in the construction of temperature-control systems shall be suitable for use with the product intended to be carried.
  • Heating or cooling media shall be of a type approved for use with the specific cargo. Consideration shall be given to the surface temperature of heating coils or ducts to avoid dangerous reactions from localized overheating or overcooling of cargo.
  • Heating or cooling systems shall be provided with valves to isolate the system for each tank and to allow manual regulation of flow.
  • In any heating or cooling system, means shall be provided to ensure that when in any condition other than empty, higher pressure can be maintained within the system than the maximum pressure head that could be exerted by the cargo tank contents on the system.
  • Means shall be provided for measuring the cargo temperature.

.1 The means for measuring the cargo temperature shall be of restricted or closed type, respectively, when a restricted or closed gauging device is required for individual substances, as shown in column “j” in the table of chapter 17.

.2 A restricted temperature-measuring device is subject to the definition of a restricted gauging device in (e.g. a portable thermometer lowered inside a gauge tube of the restricted type).

.3 A closed temperature-measuring device is subject to the definition of a closed gauging device in (e.g. a remote-reading thermometer of which the sensor is installed in the tank).

.4 When overheating or overcooling could result in a dangerous condition, an alarm system that monitors the cargo temperature shall be provided. (See also operational requirements in 16.6.)

  • When products for which 15.12, 15.12.1 or 15.12.3 are listed in column “o” in the table of chapter 17 are being heated or cooled, the heating or cooling medium shall operate in a circuit:

.1 which is independent of other ship’s services, except for another cargo heating or cooling system, and which does not enter the machinery space; or

.2 which is external to the tank carrying toxic products; or

.3 where the medium is sampled to check for the presence of cargo before it is recirculated to other services of the ship or into the machinery space. The sampling equipment shall be located within the cargo area and be capable of detecting the presence of any toxic cargo being heated or cooled. Where this method is used, the coil return shall be tested not only at the commencement of heating or cooling of a toxic product, but also on the first occasion, the coil is used subsequent to having carried an unheated or uncooled toxic cargo.

Cargo transfer
Piping scantlings

  • The minimum wall thickness shall be in accordance with recognized standards.
  • Where necessary for mechanical strength to prevent damage, collapse, excessive sag or buckling of pipes due to weight of pipes and content and to superimposed loads from supports, ship deflection or other causes, the wall thickness shall be increased over that required by 5.1.1 or, if this is impracticable or would cause excessive local stresses, these loads shall be reduced, protected against or eliminated by other design methods.
  • Flanges, valves, and other fittings shall be in accordance with recognized standards, taking into account the design pressure defined under 5.1.2.
  • For flanges not complying with a standard, the dimensions for flanges and associated bolts shall be to the satisfaction of the Administration.

Piping fabrication and joining details

  • The requirements of this section apply to piping inside and outside the cargo tanks. However, relaxations from these requirements may be accepted in accordance with recognized standards for open-ended piping and for piping inside cargo tanks except for cargo piping serving other cargo tanks.
  • Cargo piping shall be joined by welding except:
    .1 for approved connections to shutoff valves and expansion joints; and
    .2 for other exceptional cases specifically approved by the Administration.
  • The following direct connections of pipe lengths without flanges may be considered:

.1 Butt-welded joints with complete penetration at the root may be used in all applications.

.2 Slip-on welded joints with sleeves and related welding having dimensions in accordance with recognized standards shall only be used for pipes with an external diameter of 50 mm or less. This type of joint shall not be used when crevice corrosion is expected to occur.

.3 Screwed connections, in accordance with recognized standards, shall only be used for accessory lines and instrumentation lines with external diameters of 25 mm or less.

  • Expansion of piping shall normally be allowed for by the provision of expansion loops or bends in the piping system.
    .1 Bellows, in accordance with recognized standards, may be specially considered.
    .2 Slip joints shall not be used.
  • Welding, post-weld heat treatment, and non-destructive testing shall be performed in accordance with recognized standards.

Flange connections

  • Flanges shall be of the welded-neck, slip-on, or socket-welded type. However, socket-welded-type flanges shall not be used in nominal sizes above 50 mm.
  • Flanges shall comply with recognized standards as to their type, manufacture, and test.

Test requirements for piping

  • The test requirements of this section apply to piping inside and outside cargo tanks. However, relaxations from these requirements may be accepted in accordance with recognized standards for piping inside tanks and open-ended piping.
  • After assembly, each cargo piping system shall be subject to a hydrostatic test to at least 1.5 times the design pressure. When piping systems or parts of systems are completely manufactured and equipped with all fittings, the hydrostatic test may be conducted prior to installation aboard the ship. Joints welded on board shall be hydrostatically tested to at least 1.5 times the design pressure.
  • After assembly on board, each cargo piping system shall be tested for leaks to a pressure depending on the method applied.

Piping arrangements

  • Cargo piping shall not be installed under deck between the outboard side of the cargo-containment spaces and the skin of the ship unless clearances required for damage protection (see 2.6) are maintained, but such distances may be reduced where damage to the pipe would not cause the release of cargo provided that the clearance required for inspection purposes is maintained.
  • Cargo piping located below the main deck may run from the tank it serves and penetrate tank bulkheads or boundaries common to longitudinally or transversally adjacent cargo tanks, ballast tanks, empty tanks, pump-rooms, or cargo pump-rooms provided that inside the tank it serves it is fitted with a stop-valve operable from the weather deck and provided cargo compatibility is assured in the event of piping failure. As an exception, where a cargo tank is adjacent to a cargo pump room, the stop valve operable from the weather deck may be situated on the tank bulkhead on the cargo pump room side provided an additional valve is fitted between the bulkhead valve and the cargo pump. A totally enclosed hydraulically operated valve located outside the cargo tank may, however, be accepted, provided that the valve is:

.1 designed to preclude the risk of leakage;
.2 fitted on the bulkhead of the cargo tank which it serves;
.3 suitably protected against mechanical damage;
.4 fitted at a distance from the shell as required for damage protection; and
.5 operable from the weather deck.

  • In any cargo pump room where a pump serves more than one tank, a stop valve shall be fitted in the line to each tank.
  • Cargo piping installed in pipe tunnels shall also comply with the requirements of 5.5.1 and 5.5.2. Pipe tunnels shall satisfy all tank requirements for construction, location and ventilation, and electrical hazard requirements.

Cargo compatibility shall be assured in the event of a piping failure. The tunnel shall not have any other openings except to the weather deck and cargo pump room or pump room.

  • Cargo piping passing through bulkheads shall be so arranged as to preclude excessive stresses at the bulkhead and shall not utilize flanges bolted through the bulkhead.

Cargo-transfer control systems

  • For the purpose of adequately controlling the cargo, cargo-transfer systems shall be provided with:

.1 one stop-valve capable of being manually operated on each tank filling and discharge line, located near the tank penetration; if an individual deep well pump is used to discharge the contents of a cargo tank, a stop-valve is not required on the discharge line of that tank;

.2 one-stop valve at each cargo-hose connection;

.3 remote shutdown devices for all cargo pumps and similar equipment.

  • The controls necessary during transfer or transport of cargoes covered by the Code other than in cargo pump rooms that have been dealt with elsewhere in the Code shall not be located below the weather deck.

Cargo-transfer control systems

  • For the purpose of adequately controlling the cargo, cargo-transfer systems shall be provided with:
    .1 one stop-valve capable of being manually operated on each tank filling and discharge line, located near the tank penetration; if an individual deep well pump is used to discharge the contents of a cargo tank, a stop-valve is not required on the discharge line of that tank;
    .2 one-stop valve at each cargo-hose connection;
    .3 remote shutdown devices for all cargo pumps and similar equipment.
  • The controls necessary during transfer or transport of cargoes covered by the Code other than in cargo pump rooms that have been dealt with elsewhere in the Code shall not be located below the weather deck.
  • For certain products, additional cargo-transfer control requirements are shown in column o in the table of chapter 17.

Cargo tank venting and gas-freeing arrangements


  • Unless expressly provided otherwise, this chapter applies to ships constructed on or after 1 January 1994.
  • Ships constructed before 1 January 1994 shall comply with the requirements of chapter 8 of this Code which were in force prior to the said date.
  • For the purpose of this regulation, the term “ship constructed” is as defined in SOLAS regulation II-1/1.3.1.
  • Ships constructed on or after 1 July 1986 but before 1 January 1994 that fully comply with the requirements of the Code applicable at that time may be regarded as complying with the requirements of SOLAS regulations II-2/4.5.3, 4.5.6 to 4.5.8, 4.5.10 and 11.6.
  • For ships to which the Code applies, the requirements of this chapter shall apply in lieu of SOLAS regulations II-2/4.5.3 and 4.5.6.
  • Ships constructed on or after 1 July 1986, but before 1 July 2002 shall comply with the requirements of 8.3.3.

Cargo tank venting

  • All cargo tanks shall be provided with a venting system appropriate to the cargo being carried and these systems shall be independent of the air pipes and venting systems of all other compartments of the ship. Tank venting systems shall be designed so as to minimize the possibility of cargo vapor accumulating about the decks, entering accommodation, service and machinery spaces, and control stations, and, in the case of flammable vapors, entering or collecting in spaces or areas containing sources of ignition. Tank venting systems shall be arranged to prevent the entrance of water into the cargo tanks and, at the same time, vent outlets shall direct the vapor discharge
    upwards in the form of unimpeded jets.
  • The venting systems shall be connected to the top of each cargo tank and as far as practicable the cargo vent lines shall be self-draining back to the cargo tanks under all normal operating conditions of list and trim. Where it is necessary to drain venting systems above the level of any pressure/vacuum valve, capped or plugged drain cocks shall be provided.
  • Provision shall be made to ensure that the liquid head in any tank does not exceed the design head of the tank.
    Suitable high-level alarms, overflow control systems, or spill valves, together with gauging and tank filling procedures, may be accepted for this purpose. Where the means of limiting cargo tank overpressure includes an automatic closing valve, the valve shall comply with the appropriate provisions.
  • Tank venting systems shall be designed and operated so as to ensure that neither pressure nor vacuum created in the cargo tanks during loading or unloading exceeds tank design parameters. The main factors to be considered in the sizing of a tank venting system are as follows:

.1 design loading and unloading rate;

.2 gas evolution during loading: this shall be taken into account by multiplying the maximum loading rate by a factor of at least 1.25;

.3 density of the cargo vapor mixture;

.4 pressure loss in vent piping and across valves and fittings; and

.5 pressure/vacuum settings of relief devices.

  •  Tank vent piping connected to cargo tanks of corrosion-resistant material, or to tanks that are lined or coated to handle special cargoes as required by the Code, shall be similarly lined or coated or constructed of corrosion-resistant material.
  • The master shall be provided with the maximum permissible loading and unloading rates for each tank or group of tanks consistent with the design of the venting systems.

Types of tank venting systems

  • An open tank venting system is a system that offers no restriction except for friction losses to the free flow of cargo vapors to and from the cargo tanks during normal operations. An open venting system may consist of individual vents from each tank, or such individual vents may be combined into a common header or header, with due regard to cargo segregation. In no case shall shutoff valves be fitted either to the individual vents or to the header.
  • A controlled tank venting system is a system in which pressure- and vacuum-relief valves or pressure/vacuum valves are fitted to each tank to limit the pressure or vacuum in the tank. A controlled venting system may consist of individual vents from each tank or such individual vents on the pressure side only as may be combined into a common header or headers, with due regard to cargo segregation. In no case shall shut-off valves be fitted either above or below pressure- or vacuum-relief valves or pressure/vacuum valves. Provision may be made for bypassing a pressure- or vacuum-relief valve or pressure/vacuum valve under certain operating conditions provided that the
    requirement of 6.3.6 is maintained and there is a suitable indication to show whether or not the valve is bypassed.
  • Controlled tank venting systems shall consist of a primary and a secondary means of allowing full flow relief of vapor to prevent over-pressure or under-pressure in the event of failure of one means. Alternatively, the secondary means may consist of pressure sensors fitted in each tank with a monitoring system in the ship’s cargo control room or position from which cargo operations are normally carried out. Such monitoring equipment shall also provide an alarm facility that is activated by the detection of over-pressure or under-pressure conditions within a tank.
  • The position of vent outlets of a controlled tank venting system shall be arranged:

.1 at a height of not less than 6 m above the weather deck or above a raised walkway if fitted within 4 m of the raised walkway; and

.2 at a distance of at least 10 m measured horizontally from the nearest air intake or opening to accommodation, service and machinery spaces, and ignition sources.

  • The vent outlet height referred to in may be reduced to 3 m above the deck or a raised walkway, as applicable, provided that high-velocity venting valves of an approved type, directing the vapor/air mixture upwards in an unimpeded jet with an exit velocity of at least 30 m/s, are fitted.
  • Controlled tank venting systems fitted to tanks to be used for cargoes having a flashpoint not exceeding 60°C (closed-cup test) shall be provided with devices to prevent the passage of flame into the cargo tanks. The design, testing, and locating of the devices shall comply with the requirements of the Administration, which shall contain at least the standards adopted by the Organization.
  • In designing venting systems and in the selection of devices to prevent the passage of flame for incorporation into the tank venting system, due attention shall be paid to the possibility of the blockage of these systems and fittings by, for example, the freezing of cargo vapor, polymer build-up, atmospheric dust or icing up in adverse weather conditions. In this context, it shall be noted that flame arresters and flame screens are more susceptible to blockage. Provisions shall be made such that the system and fittings may be inspected, operationally checked, cleaned, or renewed as applicable.
  • Reference in 6.3.1 and 6.3.2 to the use of shutoff valves in the venting lines shall be interpreted to extend to all other means of stoppage, including spectacle blanks and blank flanges.

Cargo tank gas-freeing

  • The arrangements for gas-freeing cargo tanks used for cargoes other than those for which open venting is permitted shall be such as to minimize the hazards due to the dispersal of flammable or toxic vapors in the atmosphere and too flammable or toxic vapor mixtures in a cargo tank. Accordingly, gas-freeing operations shall be carried out such that vapor is initially discharged:

.1 through the vent outlets specified in 6.3.4 and 6.3.5; or

.2 through outlets at least 2 m above the cargo tank deck level with a vertical exit velocity of at least 30 m/s maintained during the gas-freeing operation; or

.3 through outlets at least 2 m above the cargo tank deck level with a vertical exit velocity of at least 20 m/s which are protected by suitable devices to prevent the passage of flame.

When the flammable vapor concentration at the outlets has been reduced to 30% of the lower flammable limit and, in the case of a toxic product, the vapor concentration does not present a significant health hazard, gas-freeing may thereafter be continued at the cargo tank deck level.

  • The outlets referred to in and may be fixed or portable pipes.
  • In designing a gas-freeing system in conformity with 6.5.1, particularly in order to achieve the required exit velocities of and, due consideration shall be given to the following:

.1 materials of construction of system;

.2 time to gas-free;

.3 flow characteristics of fans to be used;

.4 the pressure losses created by ducting, piping, cargo tank inlets, and outlets;

.5 the pressure achievable in the fan driving medium (e.g. water or compressed air); and

.6 the densities of the cargo vapor/air mixtures for the range of cargo to be carried.

Environmental control

  • Vapor spaces within cargo tanks and, in some cases, spaces surrounding cargo tanks may require to have specially controlled atmospheres.
  •  There are four different types of control for cargo tanks, as follows:

.1 Inerting: by filling the cargo tank and associated piping systems and, where specified in chapter 15, the spaces surrounding the cargo tanks, with a gas or vapor which will not support combustion and which will not react with the cargo, and maintaining that condition.

.2 Padding: by filling the cargo tank and associated piping systems with a liquid, gas, or vapor which separates the cargo from the air, and maintains that condition.

.3 Drying: by filling the cargo tank and associated piping systems with moisture-free gas or vapor with a dewpoint of -40°C or below at atmospheric pressure, and maintaining that condition.

.4 Ventilation: forced or natural.

  • Where inerting or padding of cargo tanks is required:

.1 An adequate supply of inert gas for use in filling and discharging the cargo tanks shall be carried or shall be manufactured on board unless a shore supply is available. In addition, sufficient inert gas shall be available on the ship to compensate for normal losses during transportation.

.2 The inert gas system on board the ship shall be able to maintain a pressure of at least 0.007 MPa gauge within the containment system at all times. In addition, the inert gas system shall not raise the cargo tank pressure to more than the tank’s relief-valve setting.

.3 Where padding is used, similar arrangements for the supply of the padding medium shall be made as required for inert gas in and

.4 Means shall be provided for monitoring ullage spaces containing a gas blanket to ensure that the correct atmosphere is being maintained.

.5 Inerting or padding arrangements or both, where used with flammable cargoes, shall be such as to minimize the creation of static electricity during the admission of the inerting medium.

  • Where drying is used and dry nitrogen is used as the medium, similar arrangements for the supply of the drying agent shall be made to those required in 9.1.3. Where drying agents are used as the drying medium on all air inlets to the tank, a sufficient medium shall be carried for the duration of the voyage, taking into consideration the diurnal temperature range and the expected humidity.

Personnel protection
Protective equipment

  • For the protection of crew members who are engaged in loading and discharging operations, the ship shall have on board suitable protective equipment consisting of large aprons, special gloves with long sleeves, suitable footwear, coveralls of chemical-resistant material, and tight-fitting goggles or face shields or both. The protective clothing and equipment shall cover all skin so that no part of the body is unprotected.
  • Work clothes and protective equipment shall be kept in easily accessible places and in special lockers. Such equipment shall not be kept within accommodation spaces, with the exception of new, unused equipment and equipment which has not been used since undergoing a thorough cleaning process. The Administration may, however, approve storage rooms for such equipment within accommodation spaces if adequately segregated from living spaces such as cabins, passageways, dining rooms, bathrooms, etc.
  • Protective equipment shall be used in any operation, which may entail danger to personnel.

Safety equipment

  • Ships carrying cargoes for which 15.12, 15.12.1, or 15.12.3 is listed in column “o” in the table of chapter 17 shall have on board sufficient but not less than three complete sets of safety equipment, each permitting personnel to enter a gas-filled compartment and perform work there for at least 20 min. Such equipment shall be in addition to that required by SOLAS regulation II-2/10.10.
  • One complete set of safety equipment shall consist of:

.1 one self-contained air-breathing apparatus (not using stored oxygen);

.2 protective clothing, boots, gloves, and tight-fitting goggles;

.3 fireproof lifeline with belt resistant to the cargoes carried; and

.4 explosion-proof lamp.

  • For the safety equipment required in 14.2.1, all ships shall carry either:

.1 one set of fully charged spare air bottles for each breathing apparatus;

.2 a special air compressor suitable for the supply of high-pressure air of the required purity;

.3 a charging manifold capable of dealing with sufficient spare air bottles for the breathing apparatus; or

.4 fully charged spare air bottles with a totally free air capacity of at least 6,000 ℓ for each breathing apparatus on board in excess of the requirements of SOLAS regulation II-2/10.10.

  • A cargo pump-room on ships carrying cargoes that are subject to the requirements of 15.18 or cargoes for which in column “k” in the table of chapter 17 toxic-vapor-detection equipment is required but is not available shall have either:

.1 a low-pressure line system with hose connections suitable for use with the breathing apparatus required by 14.2.1.

This system shall provide sufficient high-pressure air capacity to supply, through pressure-reduction devices, enough low-pressure air to enable two men to work in a gas-dangerous space for at least 1 h without using the air bottles of the breathing apparatus. Means shall be provided for recharging the fixed air bottles and the breathing apparatus air bottles from a special air compressor suitable for the supply of high-pressure air of the required purity; or

.2 an equivalent quantity of spare bottled air in lieu of the low-pressure airline.

  •  At least one set of safety equipment as required by 14.2.2 shall be kept in a suitable clearly marked locker in a readily accessible place near the cargo pump room. The other sets of safety equipment shall also be kept in suitable, clearly marked, easily accessible places.
  • The breathing apparatus shall be inspected at least once a month by a responsible officer, and the inspection recorded in the ship’s log book. The equipment shall be inspected and tested by an expert at least once a year.

Emergency equipment

  • Ships carrying cargoes, for which “Yes” is indicated in column “n” of chapter 17, shall be provided with suitable respiratory and eye protection sufficient for every person on board for emergency escape purposes, subject to the following:

.1 filter-type respiratory protection is unacceptable;

.2 self-contained breathing apparatus shall have at least a duration of service of 15 min;

.3 emergency escape respiratory protection shall not be used for fire-fighting or cargo-handling purposes and shall be marked to that effect.

  • The ship shall have on board medical first-aid equipment, including oxygen resuscitation equipment and antidotes for cargoes to be carried, based on the guidelines developed by the Organization*.
    * Reference is made to the Medical First Aid Guide for Use in Accidents Involving Dangerous Goods (MFAG), which provides advice on the treatment of casualties in accordance with the symptoms exhibited as well as equipment and antidotes that may be appropriate for treating the casualty.
  • A stretcher that is suitable for hoisting an injured person up from spaces such as the cargo pump room shall be placed in a readily accessible location.
  • Suitably marked decontamination showers and an eyewash shall be available on deck in convenient locations.
    The showers and eyewash shall be operable in all ambient conditions.

Operational requirements

Maximum allowable quantity of cargo per tank

  • The quantity of cargo required to be carried in a type 1 ship shall not exceed 1,250 m³ in any one tank.
  • The quantity of cargo required to be carried in a type 2 ship shall not exceed 3,000 m³ in any one tank.
  • Tanks carrying liquids at ambient temperatures shall be so loaded as to avoid the tank becoming liquid-full during the voyage, having due regard to the highest temperature which the cargo may reach.

Cargo information

  • A copy of this Code, or national regulations incorporating the provisions of this Code, shall be on board every ship covered by this Code.
  • Any cargo offered for bulk shipment shall be indicated in the shipping documents by the product name, under which it is listed in chapter 17 or 18 of the Code or the latest edition of MEPC.2/Circ. or under which it has been provisionally assessed. Where the cargo is a mixture, an analysis indicating the dangerous components contributing significantly to the total hazard of the product shall be provided, or a complete analysis if this is available. Such analysis shall be certified by the manufacturer or by an independent expert acceptable to the Administration.
  • Information shall be on board, and available to all concerned, giving the necessary data for the safe carriage of the cargo in bulk. Such information shall include a cargo stowage plan, to be kept in an accessible place, indicating all cargo on board, including each dangerous chemical carried:

.1 a full description of the physical and chemical properties, including reactivity, necessary for the safe containment of the cargo;

.2 action to be taken in the event of spills or leaks;

.3 countermeasures against accidental personal contact;

.4 fire-fighting procedures and fire-fighting media;

.5 procedures for cargo transfer, tank cleaning, gas-freeing, and ballasting; and

.6 for those cargoes required to be stabilized or inhibited, the cargo shall be refused if the certificate required by these paragraphs is not supplied.

  • If sufficient information, necessary for the safe transportation of the cargo, is not available, the cargo shall be
  • Cargoes that evolve highly toxic imperceptible vapors shall not be transported unless perceptible additives are introduced into the cargo.
  • Where column “o” in the table of chapter 17 refers to this paragraph, the cargo’s viscosity at 20°C shall be specified on a shipping document, and if the cargo’s viscosity exceeds 50 mPa.s at 20°C, the temperature at which the cargo has a viscosity of 50 mPa.s shall be specified in the shipping document.
  • Where column “o” in the table of chapter 17 refers to this paragraph, the cargo’s melting point shall be indicated in the shipping document.

Opening of and entry into cargo tanks

  • During handling and carriage of cargoes producing flammable and/or toxic vapors or when ballasting after the discharge of such cargo, or when loading or unloading cargo, cargo tank lids shall always be kept closed. With any hazardous cargo, cargo tank lids, ullage and sighting ports and tank washing access covers shall be open only when necessary.
  • Personnel shall not enter cargo tanks, void spaces around such tanks, cargo-handling spaces, or other enclosed spaces unless:
    .1 the compartment is free of toxic vapors and not deficient in oxygen; or
    .2 personnel wear breathing apparatus and other necessary protective equipment, and the entire operation is under the close supervision of a responsible officer.

Personnel shall not enter such spaces when the only hazard is of a purely flammable nature, except under the close supervision of a responsible officer.

Stowage of cargo samples

  • Samples that have to be kept on board shall be stowed in a designated space situated in the cargo area or, exceptionally, elsewhere, subject to the approval of the Administration.
  • The stowage space shall be:
    .1 cell-divided in order to avoid shifting of the bottles at sea;
    .2 made of material fully resistant to the different liquids intended to be stowed; and
    .3 equipped with adequate ventilation arrangements.
  • Samples that react with each other dangerously shall not be stowed close to each other
  • Samples shall not be retained on board longer than necessary.

Cargoes are not to be exposed to excessive heat

  • Where the possibility exists of a dangerous reaction of cargo, such as polymerization, decomposition, thermal instability or evolution of gas, resulting from local overheating of the cargo in either the tank or associated pipelines, such cargo shall be loaded and carried adequately segregated from other products whose temperature is sufficiently high to initiate a reaction of such cargo.
  • Heating coils in tanks carrying this product shall be blanked off or secured by equivalent means.
  • Heat-sensitive products shall not be carried in deck tanks, which are not insulated.
  • In order to avoid elevated temperatures, this cargo shall not be carried in deck tanks. goods note

When dangerous goods are offered for shipment by the sea the consignor must complete a dangerous goods document (often referred to as a dangerous goods note – DGN) and declaration of compliance with the provisions of the Code.

This documentation must be provided to the operator of the ship which is to carry the goods.

Standard information requirements

The basic items of information required for all dangerous goods consignments are:

a. The UN Number ( preceded by the letters “UN”); the proper shipping name (PSN): the UN class (division) and, when assigned, the subsidiary risk; the packing group (if applicable.

These items of information may appear in either order as follows and nothing should be interspersed in the sequence (e.g. flashpoint – see below) UN 1230, Methanol, 3, (6.1), PG II Or Methanol, 3, (6.1), un 1230, PG II

The word “class” may be inserted (e.g. UN 1230, Methanol, class 3, (6.1). PG II)
Note: there are no requirements that the name should be in capital letters or upper and lower case.

b. A description of the manner in which the consignment has been packed: i.e. the number and kind of packages/IBCs/large packaging/tanks, and the total quantity of dangerous goods covered by the description (by volume or mass)

Additional information
Where applicable, the following additional items of information must also be provided:

• The technical name where required when SP 274 appears in column 7;

• The minimum flashpoint is 61° C (c.c) or below;

• The words “EMPTY UNCLEANED” or “ RESIDUE LAST CONTAINED” before or after the PSN where the package, IBCs, or tanks concerned contain the residue of the dangerous goods:

• The word “WASTE” before the PSN where waste dangerous goods are being transported for disposal, or for processing for disposal;

• The identification of goods as “MARINE POLLUTANT”, if applicable;

• For class 1 explosives, the net explosives mass of the contents should be included in the description of the consignment;

• In the case of class 4.1 self-reactive substance or a class 5.2 organic peroxide, the control and emergency temperatures, if applicable;

• For dangerous goods consigned in salvage packaging, the words “SALVAGE PACKAGING” should be

Documentation required on board the ship

Each ship carrying dangerous goods or marine pollutants should have a special list or manifest providing full details of the goods being carried and their location on the ship.

The list or manifest should be based on the contents of the dangerous goods transport documents and certificates required by the Code and should include details of stowage locations.

Appropriate emergency response information must be available at all times for use in the event of an accident or incident involving dangerous goods. This information must be held in a location away from packages containing dangerous goods and immediately accessible in the event of an incident.

Specific stowage requirements
Stowage in relation to living quarters

Special requirements apply to goods of classes 1 (explosives), 5.2 (organic peroxides), and 7 (radioactive materials), and substances of class 3 ( flammable liquids) with a flashpoint of 23 °C or less when carried in portable tanks.

Where an instruction to stow goods clear of living quarters is listed, it means that consideration should be given to the possibility of leaking vapors penetrating accommodation, work areas, or machinery spaces through entrances, bulkhead openings, or ventilation ducts.

Stowage of marine pollutants

Where stowage on deck or under the deck is permitted, the goods should preferably be stowed under deck unless there is a weather deck that provides equivalent protection.

Where on deck only stowage is required, preference should be given to stowage on well-protected decks or inboard in sheltered areas of exposed decks.

Stowage in relation to foodstuffs

In order to avoid the possibility of contamination, toxic (class 6.1, PG I or II, class 2.3), infectious (class 6.2), corrosive (class8), radioactive (class 7), and corrosive (class 8) substances, materials and articles must be stowed so that they are adequately separated from any foodstuffs.

Stowage of solutions and mixtures

Solutions or mixtures shipped under a generic or N.O.S entry must be stowed in accordance with the stowage introductions assigned to that entry, as identified on the schedule page for the goods concerned in the DGL.

Stowage of explosives
Special towage requirements apply to the carriage of explosives (class 1)

With the exception of explosives in division 1.4, compatibility group S, there are strict limitations on the type and quantity of explosives that may be carried on different categories of vessels. On-deck stowage is usually preferred.

Segregation principles

Chapter 7.2 of the Code sets out procedures designed to ensure that adequate separation is maintained between incompatible dangerous goods.
Different dangerous goods are considered incompatible if their stowage together may result in undue hazards in the case of leakage, spillage, or any other accident.

The following standard segregation terms are used for the purposes of determining segregation requirements when dangerous goods are being transported by sea.
• “Away from”
• “Separated from”;
• “Separated by a complete compartment or hold from”;
• “Separated longitudinally by an intervening complete compartment or hold from”

Segregation table

Once any specific segregation directions found in the DGL have been taken into account, the segregation table in chapter of the Code provides the basis for segregation decisions.

The segregation decision must be based on the most stringent requirements for any dangerous goods concerned.

An “x” in the table in the box where the column and row for the classes being compared intersect indicates (in the absence of any introductions to the contrary in columns 16 and 17 of the DGL) that no segregation is required between the goods concerned, whilst a number code 1,2,3 or 4 indicates a particular level of segregation, as follows:
1. _” Away from”
2. _ “Separated from”
3. _ “Separated by a complete compartment or hold from”
4. _ Separated longitudinally by an intervening complete compartment or hold from”

Segregation between bulk materials possessing chemical hazards and packaged dangerous goods.

The segregation requirements on ships loaded with both bulk hazardous chemicals and packaged dangerous goods are identified in 7.2.6

Segregation decisions for such cargoes are based on the use of the special segregation table in sub-section 7.2.6 of the Code, taking account of any specific segregation directions in the DGL.

Temperature control

Chapter 7.7 of the Code details how the temperatures should be controlled and particular requirements to be followed, including stowage requirements, where several substances with different self-accelerating decomposition temperatures (SADT) are loaded into the same container’s cargo transport unit.

Certain substances, mainly organic peroxides of class 5.2 and self-reactive substances of class 4.1, must be carried at low temperatures.

Where a substance has to be temperature controlled, there are three temperatures levels to be established:

• Control temperature: the maximum temperature at which the substance should be carried

• Emergency temperature: the temperature at which emergency procedures should be implemented

• Self-accelerating decomposition temperature (SADT): the lowest temperature at which self-accelerating decomposition occurs.

Emergency response procedures for ships carrying dangerous goods (EmS Guide)

The use of emergency procedures involves a course in its own right. The following notes are intended to explain the purpose of emergency response procedures and how they should be used.

In order to assist vessels with advice regarding the actions to be taken on board in emergencies involving dangerous goods ( fire or spillage), IMO has published a guide, Emergency Response Procedures for ships Carrying Dangerous Goods ( EmS Guide).

The EmS Guide is divided into two sections:
• Fire
• Spillage


Detailed knowledge of dangerous goods carried on board is, of course, essential and this is covered by the following stipulation in the SOLAS Convention ( chapter VII, regulation 5,  “Each ship carrying dangerous goods shall have a special list or manifest setting forth, in accordance with the classification set out in regulation 2, the dangerous goods on board and the location thereof. A detailed stowage plan, which identifies by class and sets out the location of all dangerous goods on board, may be used in place of such a special list or manifest. A copy of one of these documents shall be made available before departure to the person or organization designated by the port state authority”

Emergency equipment

The use of the Guide implies that the vessel carries emergency equipment as required in SOLAS chapter II-2, regulation 54 (special requirements for ships carrying dangerous goods) and also as instructed in the Emergency Schedules concerned, under the heading “Special Emergency Equipment to be Carried”

It should be noted that whenever “full protective clothing” is recommended, this includes boots, coveralls, gloves, headgear, and goggles. In cases where protection of the respiratory tract is necessary, a “ self-contained breathing apparatus” is recommended, which excludes the use of goggles. In such cases additional “protective clothing” may be recommended, comprising boots, coveralls, gloves, and headgear.

Reporting Procedures
General Principles

The reporting of incidents involving harmful substances and/or marine pollutants is regulated under Protocol I of the International Convention for the Prevention of Pollution from Ships 1973, as modified by the Protocol of 1978 relating thereto (MARPOL 73/78). This Protocol entered into force on 6 April 1987.

Recognizing that incidents at sea may give rise to the accidental discharge of substances that cause pollution, MARPOL 73/78 identifies the need for any such incidents to be reported to the appropriate coastal authorities as quickly and as fully as possible.

Resolution A. 851 (20), which supplements the requirement of Protocol I, outlines the general principles for ship reporting systems and contains detailed guidelines for reporting incidents involving dangerous goods, harmful substances, and/or marine pollutants.

Guidelines for reporting incidents

Annex 1 – Procedures

This annex identifies the need for standard reports both prior to and during a voyage and allocates a coding system for their transmission.

Annex 2 – Standard reporting format and procedures

In addition to providing the format, this annex also indicates that where language difficulties may exist, the Standard Marine Communication Phrases or, alternatively, the International Code of Signals should be utilized for the report.

Annex 3 – Guidelines for detailed reporting requirements

This annex contains three sub-sections that specify the details that should be provided, respectively, in reports relating to incidents involving dangerous goods, harmful substances, and marine pollutants. These cover matters such as the proper shipping name, class, and UN Number for the substance(s) involved; the name of the manufacturer, if known (or the consignor or consignee) details of the type of packages, tank, vehicle, or freight container concerned; an estimate of the quantity involved; whether the lost goods floated or sank; whether the loss is continuing; the
cause of the loss.)

Exam Questions

2. The IBC Code applies to ships regardless of size, including those of less than 500 gross tonnage, engaged in the carriage of bulk cargoes of dangerous chemicals or noxious liquid substances (NLS), other than petroleum or similar flammable products as follows:

3. The structure, equipment, fittings, arrangements and material (other than items in respect of which a Cargo Ship Safety Construction Certificate, Cargo Ship Safety Equipment Certificate and Cargo Ship Safety Radio Certificate are issued) of a chemical tanker shall be subjected to the following surveys:

4. Ships subject to the IBC Code shall be designed to one of the following standards:

5. All ships, subject to the IBC Code, shall be fitted with a stability instrument, capable of verifying compliance with intact and damage stability requirements, approved by the Administration having regard to the performance standards recommended by the IMO (MSC.1/Circ.1229) and (MSC.1/Circ.1461), according to the following schedule:

6. Shipside discharges below the freeboard deck shall comply with the requirements of the relevant regulation of the International Convention on Load Lines in force, except that the choice of valves shall be limited to:

7. Ships subject to the IBC Code shall be capable of surviving in a condition of stable equilibrium and should satisfy the following criteria for any stage of flooding:

8. Cargoes, residues of cargoes or mixtures containing cargoes, which react in a hazardous manner with other cargoes, residues or mixtures, shall:

9. In any heating or cooling system, means shall be provided to ensure that, when in any condition other than empty, a higher pressure can be maintained within the system than the maximum pressure head that could be exerted by the cargo tank contents on the system. Means shall be provided for measuring the cargo temperatura as detailed as follow:

10. The position of vent outlets of a controlled tank venting system shall be arranged:

11. There are four different types of control for cargo tanks, as follows:

15. Personnel training shall include:

16. During handling and carriage of cargoes producing flammable and/or toxic vapours or when ballasting after the discharge of such cargo, or when loading or unloading cargo, cargo tank lids shall always be kept closed. With any hazardous cargo, cargo tank lids, ullage and sighting ports and tank washing access covers shall be open only when necessary. Personnel shall not enter cargo tanks, void spaces around such tanks, cargo-handling spaces or other enclosed spaces unless: