The document discusses the International Maritime Dangerous Goods Code which provides a uniform code for transporting dangerous goods by sea. It outlines the 9 classes of dangerous goods including explosives, gases, flammable liquids and solids, oxidizing substances, toxic and infectious substances, radioactive material, corrosives, and miscellaneous dangerous substances. It also discusses safety considerations for transporting these goods such as special emergency equipment, measuring instruments to test atmosphere, and vapour detection equipment.

1. HAZMAT – TRANSPORT OF
DANGEROUS GOODS BY SEA
Safe practice for handling and
carriage of dangerous goods
in packaged form by sea.
A. Menon

2.  The International Maritime
Dangerous Goods (IMDG) Code
was developed as a uniform
international code for the transport
of dangerous goods by sea covering
such matters as packing, container
traffic and stowage, with particular
reference to the segregation of
incompatible substances.

3.  Class 1: Explosives
 Division 1.1: substances and articles
which have a mass explosion hazard
 Division 1.2: substances and articles
which have a projection hazard but not a
mass explosion hazard
 Division 1.3: substances and articles
which have a fire hazard and either a
minor blast hazard or a minor projection
hazard or both, but not a mass explosion
hazard

4.  Division 1.4: substances and articles
which present no significant hazard
 Division 1.5: very insensitive
substances which have a mass
explosion hazard
 Division 1.6: extremely insensitive
articles which do not have a mass
explosion hazard

5.  Class 2: Gases
 Class 2.1: flammable gases
 Class 2.2: non-flammable, non-toxic
gases
 Class 2.3: toxic gases

6.  Class 3: Flammable liquids
 Class 4: Flammable solids;
substances liable to spontaneous
combustion; substances which, in
contact with water, emit flammable
gases
 Class 4.1: flammable solids, self-
reactive substances and desensitized
explosives
 Class 4.2: substances liable to
spontaneous combustion
 Class 4.3: substances which, in

7.  Class 5: Oxidizing substances
and organic peroxides
 Class 5.1: oxidizing substances
 Class 5.2: organic peroxides
 Class 6: Toxic and infectious
substances
 Class 6.1: toxic substances
 Class 6.2: infectious substances

8.  Class 7: Radioactive material
 Class 8: Corrosive substances
 Class 9: Miscellaneous
dangerous substances and
articles
 Marine pollutants and wastes
 Many of the substances assigned
to classes 1 to 9 are deemed as
marine pollutants. Certain
marine pollutants have an
extreme pollution potential and

9.  Volume 1 (parts 1, 2 and 4-7 of the
Code) contains sections on:
 general provisions, definitions, training
 classification
 packing and tank provisions
 consignment procedures
 construction and testing of packaging,
IBCs,large packaging, portable tanks
and road tank vehicles
 transport operations

10.  Volume 2 contains:
 the Dangerous Goods List
(equivalent to the schedules in
previous editions of the Code),
presented in tabular format
 limited quantities exceptions
 the Index
 appendices

11.  The Supplement contains the
following texts related to the IMDG
Code:
 EMS Guide
 Medical First Aid Guide
 Reporting Procedures
 Packing Cargo Transport Units
 Safe Use of Pesticides
 INF Code

12. PHYSICAL AND CHEMICAL
CHARACTERISTICS
Flammable: the flashpoint of a
flammable liquid is the lowest
temperature at which its vapour forms
an ignitable mixture with air. Flashpoint
figures are given in the IMDG Code. If
61° Celsius or below, they should also
be included on the dangerous goods
declaration prepared by the shipper for
each consignment.

13.  Toxic: there are a great many
substances that are toxic. They may be
either solid, liquid or gaseous.
 Corrosive: corrosive substances
cover a wide range of products such as
hydrochloric acid, sulphuric acid and
caustic soda.
 Reactive: there are other substances
which do not in themselves present
any hazard but may react violently if in
contact with certain other substances
or water.

14.  HEALTH HAZARDS
 Dangers from skin contact,
inhalation, ingestion and radiation
 There are three common ways that a
cargo can be toxic: -
 absorbed by contact through the
skin, eyes and mucous membranes
(dermal toxicity); or
 inhalation as a vapour or mist
(inhalation toxicity); or
 ingested or swallowed (oral toxicity).

15.  Radiation
 Hazards may come from either
the radioactive nature of the
material or its chemical nature.
The radioactive nature the
material may result in external
radiation or internal radiation if
the substance is inhaled,
ingested or absorbed through the
skin.

16.  SAFETY
 Handling and transport of
dangerous goods should be
carried out by the safest means
and with the greatest care in
order to prevent incidents as well
as contamination of other
cargoes and the pollution of the
environment.

17.  Special emergency equipment
 In general, ships carrying dangerous
goods should be equipped with a
sufficient quantity of fully protective
clothing, self-contained breathing
apparatus, spray nozzles (preferably
fire hoses fitted with approved dual-
purpose nozzles, i.e. spray/jet type
incorporating a shutoff) and suitable
absorbent material. Whenever an
EmS advises against the use of
electrical handtools, this does not
preclude the use of explosion-proof

18.  Electrical Safety in Cargo
Spaces
 If the compartment has the opportunity
of containing a flammable mixture then
it should always be treated as such
and the use of electrical equipment
prohibited unless the equipment is
either: -
 intrinsically safe or,

19.  within an explosion proof container or,
 an approved air pressure/positive
pressure container or,
 is an approved safety torch or,
 is approved for use in a flammable
atmosphere by being of an “increases
safety” design or,
 protected by flame paths or a flame
screen.

20.  MEASURING INSTRUMENTS
 One of the most important aspects of
safety, with regard to any work, is the
evaluation of the atmosphere. This is
especially important where the
atmosphere of a hold which has
contained/contains a chemical cargo is
being tested. The most stringent
precautions should be taken, no matter
how short the duration of work
involving personal exposure.

21.  The information which is necessary:-
 Type of atmosphere (constituents),
 Flammability - specially important if work is
to be carried out. The result of the test will
be partially dependant upon the oxygen
content of the atmosphere.
 Toxicity/Oxygen deficiency - the most
important aspect with relation to persons
entering the space in question.
 Reactivity - many chemicals can react
hazardously with water, air or other
substance entering the hold.
 Radioactivity

22.  Vapour detection equipment
 General
 The provision and use of vapour detection
equipment is required by the IMO Codes for
a number of functions, including: -
 detecting cargo vapour in air, inert gas or
the vapour of another cargo;
 measuring concentrations of gas in or near
the flammable range;
 measuring concentrations of oxygen in inert
gas or cargo vapour, or in enclosed spaces.

23.  Thermal Conductivity Meters
 Some gas detectors work by measuring
thermal conductivity of samples. They are
called thermal conductivity meters or
"catharometers", and can be used to detect
concentrations of gas from 0-100%.
 When power is applied to a heater filament
used as the sensing element its temperature
stabilises at a value depending on the thermal
conductivity of the gas around it.
 Any variation in the concentration of the gas
affects the filament temperature, resulting in a
change in electrical resistance which is

24.  Combustible Gas Detectors
 This type of equipment can be used to
detect certain combustible hydrocarbon
gases. The principle is similar to that of
the thermal conductivity meter with a
head filament of a special metal to
oxidise the gas catalytically, but the
filament temperatures are higher and the
concentration range lower (usually 0-
100% LFL). The equipment works by
resistance measurement and can be
fixed or portable.

25.  Chemical Absorption Indicators
 These instruments normally function by
drawing a sample of vapour through a
chemical reagent in a glass tube. The
detecting reagent becomes progressively
discoloured if vapour is present and the
length of discoloration - which can be
read from the tube or from a graduated
scale - gives a measure of vapour
concentration.

26.  Oxygen Analysers
 There are several types of oxygen
analysers; some are chemical absorption
indicators using special tubes, others
use chemicals to dissolve oxygen from a
sample and yet others rely on the
paramagnetic property of oxygen.
 If detector tubes are used the readings
may be affected by the presence of
chemical vapours..

27. An indicator which may be reliable for
measuring the oxygen content of a
space after thorough ventilation may not
be suitable for checking the oxygen
content of an air/inert gas/cargo vapour
mixture. Manufacturers' instructions
should be observed

28. THANK YOU