Ignition Temperature
The ignition temperature of a material, formerly known as auto-ignition temperature is the minimum temperature, under prescribed test conditions, at which the material can ignite and sustain combustion, when mixed with air at normal pressure, without a source of ignition.
Ignition temperature is clearly distinguished from flash point. They have no relationship to each other.
The temperature class of a gas or vapour is given according to IEC 60079-20-1 in the table shown:
NOTE
gases with IT between 85°C to 100°C are considered to be T6 to allow an increased design safety factor