Essential oils are extracted from plant material using steam or water distillation, cold pressing and Co2 extraction.
Selected plant materials are heated with steam, water or both until the essential oil vaporises. The oil then condenses as it cools.
All volatile aromatic plant oils are extremely concentrated plant oils. They should be used sparingly, only a few drops at a time and always diluted in some other medium, such as cold pressed vegetable oil (massage oil) and/or unscented base cream (but not a mineral oil cream, such as most brands of sorbolene or baby oil, these do not absorb into the skin).
Aromatic plant oils do not dissolve in water unless mixed with a dispersant or solubiliser, first.
Essential oils can be massaged into the skin, added to bath water or vaporised in an oil burner.
Aromatic plant oils, including essential oils, should not be ingested (taken in by mouth) as they can be toxic.