Vegetable oils obtained by pressing or extraction contain various undesirable impurities, which are small particles of seeds and do not allow direct use of oil containing them for food and technical purposes. Impurities can be divided into oil-soluble and insoluble.

Insoluble in oil include small particles of seeds that got into the oil during processing. Soluble impurities include phosphorus (in oil it is in the form of phospholipids), resins, pigments, waxy and volatile substances. These substances cause undesirable coloring of the oil, contribute to the appearance of odor at high temperatures and stick to hot surfaces, which makes it impossible to use the oil both in the food industry and for technical purposes.

Technological equipment for oil filtration and refining provides purification.