ADR Class 2: Gases

The title of gases covers pure gases, mixtures of gases, mixtures of one or more gases with other materials and objects containing them. Gas is understood to mean:

At 50ºC its vapor tension is higher than 3 bar.
Fully gaseous at 20ºc and one atmosphere of pressure
Its flash point is less than or equal to 60ºC.
The critical temperature of a gas is the temperature at which, once reached, the gas cannot be liquefied even by compression.

Class 2 Divisions

Class 2 materials and objects are subdivided into:

Compressed gas:
gas which, when packaged under pressure is gaseous at -50ºC, all gases whose critical temperature is below -50ºC may be compressed to be liquefied.
Liquefied gas:
gas which when packaged under pressure is partially liquid at temperatures above -50ºC, two types are distinguished:
- High pressure liquefied gas
- Low pressure liquefied gas
Refrigerated liquefied gas:
a gas that is partially liquid when packaged due to the low temperature.
Dissolved gas:
a gas that when packaged is dissolved in a solvent in liquid form.

Aerosol generators:
and small capacity containers containing gases.
Other objects containing pressurized gas
Uncompressed gases
subject to special provisions
Pressurized chemical products:
liquid, pasty or powdery material under pressure to which a propellant gas is added for subsequent emptying, the gases will be compressed, liquefied.
Absorbed gas:
a gas absorbed under a support of solid porous material with an internal pressure of the vessel less than 1 atmosphere at 20ºC and less than 3 atmospheres at 50ºC.

Class 2 ADR groups

Substances and articles of Class 2 with the exception of aerosols and chemicals in pressure vessels are assigned to the following groups according to their hazardous properties:

The groups with the letter T prevail over the other groups of letters, i.e. F, O, A, in the same way that the letter F prevails over O, A. Corrosivity for gases is considered a criterion of toxicity, i.e. corrosive gases are considered toxic: TC, TFC, TOC.

Gases

Class 2 materials and objects not mentioned in Table A of Chapter 3.2 are assigned to the collective heading of Table 2.2.2.2.3 by applying the following criteria:

Asphyxiating gases: these are non-combustible, non-toxic and non-flammable gases that only dilute or replace oxygen in the air.
Flammable gases: are flammable gases when their mixture with air reaches 13% or if the upper flammability limit is at least 12%, regardless of the lower limit.
Combustion gases: these are gases that can cause or favor fires due to the contribution of oxygen for the combustion of materials, provided that the percentage of combustion gas exceeds 23.5% will be considered as such.
Toxic Gases: These are gases known to be toxic and corrosive to humans and harmful to health. They are toxic and corrosive gases to humans by virtue of acute inhalation toxicity LC50 less than 5,000 ml/m3. The following formula shall be used for the classification of gas mixtures:
Corrosive Gases: Gases that entirely correspond to corrosivity criteria shall be considered as toxic with subsidiary danger of corrosive.

Aerosols

Aerosols are assigned to a group listed below based on hazardous properties:

The classification depends on the nature of the contents of the aerosol generator.

A is assigned when neither F, O, T, C nor the other groups CO, FC, TF, TC, TO, TFC, TOC are considered.....
O is assigned when the gas containing it is oxidizing.
F is assigned if the mass content corresponds to 85% in components of flammable material, the propellant gas plus the ingredient to be expelled.
T is assigned if the contents are classified as toxic by 6.1 GE II or III and not by the propellant or propellant gas generating the aerosol.
C is assigned if the contents are classified as corrosive by 8 GE II or III and not by the propellant gas or aerosol-generating propellant.
It is assigned to any other combination if none of them correspond to T, F, O or C.

Pressurized chemicals

Pressurized chemicals are assigned to the following groups according to their hazardous properties:

The classification will depend on the hazard characteristics of the components in the different states (Dispersing Agent, Liquid or Solid). The following criteria will be applied to assign the groups:

Assignment A will be when none of the criteria after this one are met.
The F corresponds to the components being classified as flammable whether they are liquids or mixtures of liquids, solids or mixtures of solids, gases and their flammable gas mixtures.
T when the contents are classified as MMPP Class 6.1 GE II or III other than propellant gas.
C when the contents are classified as MMPP Class 8 GE II or III other than propellant gas.
It is assigned to any other combination if none corresponds to T, F, or C or FC and TF as appropriate.

Personal protective equipment for Class 2

When handling ADR Class 2 materials, you must be properly equipped to be prepared for any incident that may occur. The necessary equipment is:

Face shield
Respiratory protection equipment, both nasal and facial.
Antistatic protective gloves
Antistatic chemical body protection: the generation of static electricity in the transfer of flammable liquids; the accumulation of electrostatic charges is the sum of two components: the formation, on the other hand inevitable in the case of flammable materials, and their dissipation, i.e. the ability of this material to recombine itself without the need to generate dangerous potentials.

Materials with a flash point equal to or lower than 61ºC must have the correct electrical conductivity for their correct handling. Therefore, equipotential connections and grounding points must exist throughout the plant in order to dissipate electrical charges and return them to ground, minimizing dangerous potentials.

Package labeling

When ADR shipments of Class 2 materials are made, labeling must be visible together with the approval markings on the containers and packages.

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ADR Class 2: Gases

Class 2 Divisions

Class 2 ADR groups

Gases

Aerosols

Pressurized chemicals

Personal protective equipment for Class 2

Package labeling