This International Standard specifies a procedure for the determination of flash and fire points of petroleum products using the Cleveland open cup apparatus. It is applicable to petroleum products having an open cup flash point above 79 °C, except fuel oils, which are most commonly tested by the closed cup procedure described in ISO 2719 [1]. NOTE Flash point and fire point are indications of the ability of a substance to form a flammable mixture with air under controlled conditions, and then to support combustion. They are only two of a number of properties that may contribute towards the assessment of overall flammability and combustibility of a material.