CELEX 02008R1272 · v20250901

2.2. Flammable gases

2.2.1.1.

Flammable gas means a gas or gas mixture having a flammable range with air at 20 °C and a standard pressure of 101,3 kPa.

2.2.1.2.

A pyrophoric gas means a flammable gas that is liable to ignite spontaneously in air at a temperature of 54 °C or below.

2.2.1.3.

A chemically unstable gas means a flammable gas that is able to react explosively even in the absence of air or oxygen.

▼M4

2.2.2. Classification criteria

▼M19

2.2.2.1. A flammable gas is classified in Category 1A, 1B or 2 in accordance with Table 2.2.1. Flammable gases that are pyrophoric and/or chemically unstable are always classified in Category 1A.

Table 2.2.1

Criteria for categorisation of flammable gases

Category			Criteria
1A	Flammable gas		Gases, which at 20 °C and a standard pressure of 101,3 kPa are: (a) ignitable when in a mixture of 13 % or less by volume in air; or (b) have a flammable range with air of at least 12 percentage points regardless of the lower flammability limit unless data show they meet the criteria for Category 1B
	Pyrophoric gas		Flammable gases that ignite spontaneously in air at a temperature of 54 °C or below
	Chemically unstable gas	A	Flammable gases which are chemically unstable at 20 °C and a standard pressure of 101,3 kPa
		B	Flammable gases which are chemically unstable at a temperature greater than 20 °C and/or a pressure greater than 101,3 kPa
1B	Flammable gas		Gases which meet the flammability criteria for Category 1A, but which are not pyrophoric, nor chemically unstable, and which have at least either: (a) a lower flammability limit of more than 6 % by volume in air; or (b) a fundamental burning velocity of less than 10 cm/s;
2	Flammable gas		Gases, other than those of Category 1A or 1B, which, at 20 °C and a standard pressure of 101,3 kPa, have a flammable range while mixed in air.

NOTE 1: Aerosols shall not be classified as flammable gases. See Section 2.3.

NOTE 2: In the absence of data allowing classification into Category 1B, a flammable gas that meets the criteria for Category 1A is classified by default in Category 1A.

NOTE 3: Spontaneous ignition for pyrophoric gases is not always immediate, and there may be a delay.

NOTE 4: In the absence of data on its pyrophoricity, a flammable gas mixture shall be classified as a pyrophoric gas if it contains more than 1 % (by volume) of pyrophoric component(s).

▼M4

2.2.3. Hazard Communication

Label elements shall be used for substances and mixtures meeting the criteria for classification in this hazard class in accordance with Table 2.2.3.

▼M19

Table 2.2.2

Label elements for flammable gases

	Category 1A	Gases categorised as 1A meeting pyrophoric or unstable gas A/B criteria			Category 1B	Category 2
		Pyrophoric gas	Chemically unstable gas
		Pyrophoric gas	Category A	Category B
GHS Pictogram						No pictogram
Signal Word	Danger	Danger	Danger	Danger	Danger	Warning
Hazard Statement	H220: Extremely flammable gas	H220: Extremely flammable gas. H232: May ignite spontaneously if exposed to air	H220: Extremely flammable gas. H230: May react explosively even in the absence of air	H220: Extremely flammable gas. H231: May react explosively even in the absence of air at elevated pressure and/or temperature	H221: Flammable gas	H221: Flammable gas
Precautionary Statement Prevention	P210	P210 P222 P280	P202 P210	P202 P210	P210	P210
Precautionary Statement Response	P377 P381	P377 P381	P377 P381	P377 P381	P377 P381	P377 P381
Precautionary Statement Storage	P403	P403	P403	P403	P403	P403
Precautionary Statement Disposal

▼M19

If a flammable gas or gas mixture is classified as pyrophoric and/or chemically unstable, then all relevant classification(s) shall be communicated on the safety data sheet as specified in Annex II of Regulation (EC) No 1907/2006, and the relevant hazard communication elements included on the label.

▼M19

The classification procedure is set out in the following decision logic (see Figure 2.2.1).

Figure 2.2.1

Flammable gases

Text of image

(1) In the absence of data on its pyrophoricity, a flammable gas mixture shall be classified as a pyrophoric gas if it contains more than 1 % (by volume) of pyrophoric component(s).

Text of image

▼M19 —————

▼M4

2.2.4. Additional Classification Considerations

▼M19

2.2.4.1. Flammability shall be determined by tests or, for mixtures where there are sufficient data available, by calculation in accordance with the methods adopted by ISO (see ISO 10156 as amended, ‘Gases and gas mixtures — Determination of fire potential and oxidising ability for the selection of cylinder valve outlets’ and, if using fundamental burning velocity for Category 1B, see ISO 817 as amended ‘Refrigerants-Designation and safety classification, Annex C:- Method of test for burning velocity measurement of flammable gases’). Instead of the test apparatus according to ISO 10156 as amended, the test apparatus for the tube method according to clause 4.2 of EN 1839 as amended (Determination of explosion limits of gases and vapours) may be used.

▼M19

2.2.4.2. Pyrophoricity shall be determined at 54 °C in accordance with either IEC 60079-20-1 ed1.0 (2010-01) ‘Explosive atmospheres – Part 20-1: Material characteristics for gas and vapour classification – Test methods and data’ or DIN 51794 ‘Determining the ignition temperature of petroleum products’.

2.2.4.3. The classification procedure for pyrophoric gases need not be applied when experience in production or handling shows that the substance does not ignite spontaneously on coming into contact with air at a temperature of 54 °C or below. Flammable gas mixtures, which have not been tested for pyrophoricity and contain more than one percent pyrophoric components, shall be classified as a pyrophoric gas. Expert judgement on the properties and physical hazards of pyrophoric gases and their mixtures shall be used in assessing the need for classification of flammable gas mixtures containing one percent or less pyrophoric components. In this case, testing need only be considered if expert judgement indicates a need for additional data to support the classification process.

▼M4

►M19 2.2.4.4. ◄ Chemical instability shall be determined in accordance with the method described in Part III of the UN RTDG, Manual of Tests and Criteria. If the calculations in accordance with ISO 10156 as amended show that a gas mixture is not flammable it is not necessary to carry out the tests for determining chemical instability for classification purposes.

Source: Content sourced from EUR-Lex and licensed under CC BY 4.0. This is an unofficial presentation; only the official EUR-Lex version is legally authentic.

2.2. Flammable gases