Flash point - Characteristics of Hydrocarbons
The minimum temperature at which an oil provides enough vapours to form an explosive mixture with air is considered as flash point of the oil.
The flash point in middle Asia is fixed at 44oC, in France it is fixed at 35oC, and in England at 22.8oC. The flash point of oil is usually ascertained by means of "Abel's apparatus".
Chemists have made some hydrocarbons with octane number even less than zero (for example n-nonane has octane number - 45) also hydrocarbon along with octane number bigger than 100 (for example 2, 2, 3 trimethyl-butane. has octane number of 124).