A substance which—

1. a

   has a critical temperature below 50°C or which at 50°C has a vapour pressure of more than 3 bars absolute; and

2. b

   is carried at a pressure of more than 500 millibars above atmospheric pressure or in liquefied form,

other than a toxic gas or a flammable gas.

Non-flammable compressed gas.

A substance which has a critical temperature below 50°C or which at 50°C has a vapour pressure of more than 3 bars absolute and which is toxic.

Toxic gas.

A substance which has a critical temperature below 50°C or which at 50°C has a vapour pressure of more than 3 bars absolute and is flammable. (See Note 1)

Flammable gas.

A liquid with a flash point of 55°C or below except a liquid which—

1. a

   has a flash point equal to or more than 21°C and less than or equal to 55°C; and

2. b

   when tested at 55°C in the manner described in Schedule 2 to the Highly Flammable Liquids and Liquefied Petroleum Gases Regulations (Northern Ireland) 197555 does not support combustion.

(See Notes 1 and 2)

Flammable liquid.

A solid which is readily combustible under conditions encountered in carriage or which may cause or contribute to fire through friction.

Flammable solid.

A substance which is liable to spontaneous heating under conditions encountered in carriage or to heating in contact with air being then liable to catch fire.

Spontaneously combustible substance.

A substance which in contact with water is liable to become spontaneously combustible or to give off a flammable gas.

Substance which in contact with water emits flammable gas

A substance other than an organic peroxide which, although not necessarily combustible, may by yielding oxygen or by a similar process cause or contribute to the combustion of other material.

Oxidizing substance

A substance which is—

1. a

   an organic peroxide; and

2. b

   an unstable substance which may undergo exothetmic self-accelerating decomposition.

Organic peroxide

A substance known to be so toxic to man as to afford a hazard to health during carriage or which, in the absence of adequate data on human toxicity, is presumed to be toxic to man.

Toxic substance.

A substance known to be toxic to man or, in the absence of adequate data on human toxicity, is presumed to be toxic to man but which is unlikely to afford a serious acute hazard to health during carriage.

Harmful substance.

A substance which by chemical action will—

1. a

   cause severe damage when in contact with living tissue; or

2. b

   materially damage other freight or equipment if leakage occurs.

Corrosive substance.

A substance which is listed in Part 2 of the approved carriage list and which may create a risk to the health or safety of persons in the conditions encountered in carriage whether or not it has any of the characteristic properties referred to above.

Other dangerous substance.

Packages containing two or more dangerous substances which have different characteristic properties.

Mixed hazards.