Solvent extraction follows a similar process to steam distillation, except that it uses a solvent rather than water to separate the CBD oil from the plant material. This creates a resulting mixture of the Hemp Oil with the solvent. The solvent then evaporates, leaving pure Hemp Oil behind. Solvent extraction uses either hydrocarbons or natural solvents.
Solvent extraction is more efficient than steam distillation, and it’s also less expensive. However, the solvents used in hydrocarbon extraction (including naphtha, petroleum, butane, or propane) create cause for concern. The solvent residue can be toxic and increase one’s cancer risk if they aren’t fully eliminated during the evaporation step—which doesn’t always happen. Some studies have found traces of petroleum or naphtha hydrocarbons residue in CBD products that used solvent extraction.
To avoid the risk of toxic residue, solvent extraction can use natural solvents instead, such as olive oil or ethanol. These solvents are just as effective at extracting CBD oil, but remove the risk of toxic residue.
However, natural solvent extraction is not without its downsides. When natural solvents like ethanol are used, chlorophyll may also be extracted. This gives the resulting oil an unpleasant taste. If the CBD is used in capsules or topicals, this isn’t a big deal, but many CBD products are eaten or inhaled (such as gummies, tinctures, vape oils), so this can make them harder to sell.
The larger problem with natural solvents, though, is that they don’t evaporate very well. As a result, the CBD extract contains a lower concentration of CBD than it would with other methods.