Division 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.F1F2

Gases, which at 20 °C and a standard pressure of 101,3 kPa are:

1. (a)

   ignitable when in a mixture of 13 % or less by volume in air; or

2. (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

Gases which meet the flammability criteria for Category 1A, but which are not pyrophoric, nor chemically unstable, and which have at least either:

1. (a)

   a lower flammability limit of more than 6 % by volume in air; or

2. (b)

   a fundamental burning velocity of less than 10 cm/s;