Flash point and fire point are the two most critical safety parameters of lubricating oils and fuels, governing their storage classification, transport regulations, and operational temperature limits. The flash point is the lowest temperature at which oil vapours momentarily ignite when the test flame is applied; the fire point is the slightly higher temperature at which ignition is sustained for at least five seconds. This experiment uses the Pensky-Martens closed cup apparatus (ASTM D93 / IP 34), the internationally recognised standard for oils with flash points above 40°C. The closed cup retains volatiles in contact with the liquid surface, giving lower (more conservative) flash point values than open cup methods. The procedure involves slowly heating the oil at 5–6°C/min with continuous stirring, applying the test flame every 2°C within 17°C of the expected flash point, and recording the temperature at which a distinct blue flash is observed. The thermodynamic basis is fully explained, and ASTM and GHS regulatory categories are discussed. The experiment requires mandatory safety precautions including a CO2 fire extinguisher within arm's reach.