Essential oil is a concentrated hydrophobic liquid containing volatile compounds from plants. It is “essential” in the sense that it contains the “essence of” the plant’s fragrance-the characteristic fragrance of the plant from which it is derived. Various parts of different plants are used to extract the essential oil. For instance from flower chamomile, ylang-ylang, jasmine, anthopogon, rose etc, from leaves sweet neem, davana, guava leaf, wintergreen, citronella, palmarosa etc from rhizomes calamus, spikenard, valerian, zedoary etc, from softwood sandalwood, cedarwood etc, from seed juniper berry, nutmeg, cinnamon berry etc from resin frankincense. They are generally extracted by distillation, often by using steam or cold pressing. Most of the essential oil like lavender, lemongrass, wintergreen, palmarosa, juniper berry and so on are extracted by steam distillation and a citrusy essential oil like lemon, orange, bergamot and so on are extracted by cold pressing. They are used in perfumes, cosmetics, soaps and other products, for flavouring food and drink, and for adding scents to incense and household cleaning products. They are often used for aromatherapy, a form of alternative medicine in which healing effects are ascribed to aromatic compounds. The way of applying essential oil differ for every individual some of them use it through a diffuser for inhaling, some of them use it topically by mixing a few drops on vegetable oils, moisturizers. Traditionally, people consume some of the essential oil for digestion, cancerous cell, immunity. Similarly, a massive number of people consume essential oil in this era as well, but there is controversy related to this topic whether we can consume it or not. During analysis, very few essential oils contain tiny percentages of allergens like linalool, limonene that’s why apply them with great care. Improper use of essential oil may cause harm including allergic reactions, inflammation and skin irritation, and children may be particularly susceptible to the toxic effects of improper use. Pregnant women or people having any medical problem use it only under the proper guidance of qualified aromatherapy practitioners.