The oily liquid obtained from plants through a variety of processes. The essential oil usually has the taste and smell of the original plant. Essential oils are called volatile because most of them are easily vaporized. The only theories for calling such oils essential are (1) the oils were believed essential to life and (2) they were the “essence” of the plant. The use of essential oils as preservatives is ancient. A large number of oils have antiseptic, germicidal and preservative action; however, they are used primarily for fragrances and flavorings.