3.3.5. Flash Points
Flash point of a fuel can be defined as the temperature at which the fuel can ignite when exposed to a heat source. This is of importance when safe handling, storage and transportation are involved [2]. The flash points of PKO and palm kernel biolubricants samples PKBLT and PKBLE were 210 °C, 235 °C and 240 °C, respectively. Thus, the products are categorized as non-hazardous products due to their high flash point values. With respect to lubricants, flash point of a lubricant is the temperature at which some vapor is emitted from the lubricant to temporarily ignite a flame [1]. Flash point is a very important property that must be considered in evaluating the overall flammability hazard of a biolubricant, as well as other similar materials. On the other hand, the flash point of the petroleum lubricant was 220 °C. The obtained results were similar to those reported by Alang et al. [1] (>210) and Salih et al. [17] (>300), for PKO biolubricant. These flash point values of the obtained PKO biolubricants samples were also in the range of those reported by Aji et al. [38] for Neem biolubricant (262 °C) and by Bilal et al. [44] for Jatropha biolubricant (274 °C).