| Class |
Sub
class |
Symbol |
Description |
Examples |
| Class 2
Gases |
Class 2.1
Flammable gases |
 |
These are gases which
will burn. |
acetylene
hydrogen
LPG |
| 
|
Class 2.2
Non-flammable
Non-toxic gases |
 |
These gases are usually
compressed and so are a source of stored energy and
some may also present an anoxic hazard (that is, they
will exclude oxygen and so kill through asphyxiation).
These containers may rocket if valves are damaged
or containers are involved in a fire. |
air
carbon dioxide
nitrogen |
|
|
Class 2.3
Poisonous gas |
 |
These gases are toxic.
Being gases, they will rapidly disperse if there is
a leak. This may reduce the concentration and the
hazard - but it will also spread the gas further,
so increasing the risk of poisoning more people. |
chlorine
methyl bromide
nitric oxide |
| Class 3
Flammable liquids |
|
 |
These liquids will
all burn. |
petrol
kerosene |
| Class 4
Flammable solids |
Class 4.1
Flammable solids, self-reactive and related substances
and desensitised explosives |
 |
Solids easily ignited
and readily combustible. These are ordinarily flammable
solids which don't fit into Class 4.2 or 4.3. |
sulphur
phosphorus
picric acid |
|
|
Class 4.2
Spontaneously combustible |
 |
These materials will
catch fire if exposed to air without any heat being
applied (that is, the heat from the normal air is
sufficient for them to catch fire - no other source
of heat is required). |
charcoal (non-activated) |
|
|
Class 4.3
Dangerous when wet |
 |
This class is also
known as 'Emits flammable gases when wet'. This class
has a particular hazard: not only can moisture from
the air cause a fire, but if water or foam is used
to extinguish them, it will make the situation worse. |
calcium carbide |
| Class 5
Oxidising substances |
Class 5.1
Oxidising agent |
 |
These are all oxidising
agents other than organic peroxides. When substances
burn in air, they combine with oxygen and so are said
to have been oxidised. Other chemicals have a similar
'burning' effect and so are said to be oxidising agents.
The largest group of these are the organic peroxides. |
chlorine
calcium hypochlorite
sodium peroxide |
|
|
Class 5.2
Organic peroxides
(liquid or solid) |
 |
These are a particular
class of oxidising agent. They have all the normal
hazards of oxidising agents (that is, they will cause
a 'chemical burning'). In addition, they will often
be explosive under certain conditions - especially,
if they are allowed to dry out. |
benzoyl peroxides
methyl ethyl
ketone peroxides (MEKP) |
| Class 6
Poisonous and infectious substances |
Class 6.1
Poisons |
 |
These are liable to
cause death or serious injury to human health if inhaled,
swallowed or absorbed through the skin. They are covered
by special regulations and need special registration.
It is acceptable to use the word 'toxic' to replace
the word 'poison'. |
cyanides
lead
arsenic |
| |
|
 |
|
|
|
|
Class 6.2
Infectious substances |
 |
Substances containing
viable micro-organisms that may cause disease in humans
or animals. |
diagnostic specimens
or live vaccines |
| Class 8
Corrosives |
|
 |
These chemicals will
eat away at a wide range of materials including some
materials of construction for tanks and probably your
eyes and skin.
Care must be taken to ensure the
containers and packages are made from the right materials
and the chemicals do not contact your clothes, skin
or eyes.
Special protective equipment needs
to be worn. |
hydrochloric acid
sodium hypochlorite (liquid pool
chlorine)
sodium hydroxide (caustic soda) |
| Class 9
Miscellaneous goods |
|
 |
Substances and articles
which have potentially dangerous properties that are
relatively minor, or are not covered by any of the
classes already described. |
aerosols
polyester beads |
