Each type of oil contains a mixture of natural chemical compounds unique to that species of plant and to the environment in which the plant is grown. For thousands of years, humans have ingested plants in the form of food as well as plant parts and extracts as herbal health products and teas from leaves and flowers, which contain essential oils.
One could argue that it should also be safe to ingest essential oils in small quantities, just as we have been doing when ingesting plants containing essential oils. Because they are produced naturally by plants, essential oils are found in naturally balanced mixtures. Then why is there an ongoing concern about the internal use of essential oils? Internal use can not only be very effective, but is also safe. Oils first have an effect on local tissues. – See more at: http://doterra.com/US/en/blog/safety-physiology-is-it-safe-to-ingest-essential-oils#sthash.95jDscsR.dpuf