Expeller pressed oil is the type of oil that is extracted from nuts or seeds by using a process that crushes them. This kind of method is markedly different from the other kinds of oil extraction methods being used by other manufacturers. A large number of manufacturer get expeller pressed oil from their sources and then just treat the extracted oil with different chemicals like Hexane in order to get the remaining oil from the source. This is done because expeller pressed oil methods are not as efficient. Only about 66 percent of oil from nuts and seeds are extracted with this method, which means there is only a low oil yield.
But there are companies, especially those that are in the natural foods sector, who believe that a lower yield is a better result than having to chemically treat the seeds just to extract more oil. The main concern, according to these companies, is that by chemically treating the expeller pressed oils, residues of the chemical will remain with the final product. Expeller pressed oil is generally considered as more expensive but according to companies that solely make this product, the quality of the oil is better and also healthier.
According to studies, it has been confirmed that large quantities of Hexane can be dangerous to humans. Inhalation of Hexane can cause nausea, sleepiness and headaches. Chronic inhalation of this chemical will cause cramping and muscle weakness and can even cause muscular deterioration. These effects only mean that Hexane has a direct effect on the central nervous system.