Viscosity of White Oils

White oils are purified mineral oils that are clear and colorless oil-like blends of hydrocarbons. They are obtained from the liquid byproducts of kerosene processing, which are alternately treated with sulfuric acid and sodium hydroxide solution to remove coloring impurities. If required, the product can finally be filtrated over animal charcoal. White oils have different chemical compositions, but in general they contain blends of saturated paraffinic, naphthenic, and acrylic saturated hydrocarbons. White oils are insoluble in water and alcohol, but soluble in solvents like ethers, benzene, and chloroform, amongst others. In contrast to triglycerides, white oils do not become rancid and, moreover, they do not develop acids. 

Due to their versatility, white oils can be used in a wide range of applications and can be added to other products without reducing their quality. Their lack of distinctive physical properties lets them be used as additives without compromising the color, scent, or flavor of the final product. Although they are often used as lubricating agents, they can also be used as coolants, sealants, and binders in different applications. Furthermore, white oils can be used as process oils in the plastic industry, as softeners in the textile industry, and as lubricants or preservatives in the food industry.

Depending on their quality, a distinction can be made between technical-grade and medicinal-grade white oils. Technical white oils are of lower quality and typically contain a higher amount of aromatic and polycyclic aromatic hydrocarbons (PAHs). They are typically used in application areas like mechanics, electronics, the automotive industry, and metal fabrication as well as fabric and rubber manufacturing. More specifically, white oils are used as lubricants for sewing machines, bicycles, watches, and other valuable machinery or precision mechanics.

Medicinal-grade oils are refined to a high degree so that they are suitable for internal medical use. White oils of such high quality can be used in medical, pharmaceutical, veterinary, or cosmetic applications (e.g., as laxatives in medicine or as skin oil ingredient in cosmetics). Medicinal white oils are non-comedogenic and will not support pathogenic bacterial growth. White oils for production of drugs, pharmaceuticals, cosmetics, etc. must fulfill several specifications, such as US FDA 21 CFR 172.878, US FDA 21 CFR 178.3570, US FDA 21 CFR 178.3620 “White mineral oil,” USDA H1, and European pharmacopoeia like the Deutsches Arzneibuch DAB. The production lines must be certified according to ISO 9001.

One important parameter for the quality control of white oils is their viscosity. Depending on their intended purpose, a certain viscosity is required to ensure perfect mixing with other components in the production process or for reliable lubrication of machinery. When used at different temperatures, the viscosity index (VI) is also important to describe the temperature dependence of the viscosity.

* Calculated values

** Measured with SVM 4001

* Maximum two temperatures