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2.14 Class 2, Gases, has three divisions:
(a) Class 2.1, Flammable Gases, which consists of gases that, at 20°C and an absolute pressure of 101.3 kPa,
(i) are ignitable when in a mixture of 13 percent or less by volume with air, or
(ii) have a flammability range with air of at least 12 percentage points determined in accordance with tests or calculations in ISO 10156;
(b) Class 2.2, Non-flammable and Non-toxic Gases, which consists of gases that are transported at an absolute pressure greater than or equal to 280 kPa at 20°C, or as refrigerated liquids, and that are not included in Class 2.1, Flammable Gases, or Class 2.3, Toxic Gases; and
(c) Class 2.3, Toxic Gases, which consists of gases that
(i) are known to be toxic or corrosive to humans according to CGA P-20, ISO Standard 10298 or other documentary evidence published in technical journals or government publications, or
(ii) have an LC50 value less than or equal to 5,000 mL/m3.