Lubricating oils 99%

The term ‘lubricating oil’ refers to a wide range of products that are characterized by hundreds of base chemicals and additives. Lubricating oils may be either mineral-based or synthetic. The mineral-based are more widely used than the synthetic oils. This article focuses on petroleum-based lubricating oils, which are composed of 80–90% of petroleum hydrocarbon distillates and 10–20% of additives. Additives are necessary to impart specific properties to the oil for specific applications and include among others ‘extreme pressure additives,’ antiwear additives, corrosion inhibitors, oxidation inhibitors, viscosity index improvers, or demulsifiers.Lubricating oils are a complex combination of hydrocarbons obtained from solvent extraction and dewaxing processes. It consists predominantly of saturated hydrocarbons having carbon numbers in the range C15 through C50, with the heavier distillates having higher percentages of the higher carbon number compounds. The mineral-based oils are produced from heavy-end crude oil distillates and they contain hundreds to thousands of hydrocarbon compounds, including a substantial fraction of nitrogen- and sulfur-containing compounds. The hydrocarbons are mainly mixtures of straight and branched chain hydrocarbons (alkanes), cycloalkanes, and aromatic hydrocarbons. PAHs (polycyclic aromatic hydrocarbons), alkyl PAHs, and metals are important components of motor oils and crankcase oils. Lubricating oil composition changes under the use conditions of heat and friction and, if appropriate, exposure to exhaust gases of internal combustion engines. Used lubricating oils or crankcase oils generally have higher concentrations of PAHs than unused oils and they are considered to be more toxic. Used lubricating oils are not specifically addressed in this article.The petroleum hydrocarbon distillate generally consists of paraffinic or naphthenic compounds. The exact composition of mineral-based lubricating oil as petroleum products varies depending upon (1) the source of the crude oil (crude oil is derived from underground reservoirs which vary greatly in their chemical composition) and (2) the refining practices used to produce the product. All the lubricating oils listed in Table 1 have been classified in Europe on the basis of the Global Harmonized System (GHS) as carcinogen category 1B (known or presumed to have carcinogenic potential for humans based primarily on animal evidence) with the hazard statement of H350 may cause cancer.