Essential oil
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An essential oil, also known as volatile oil and ethereal oil, is a water-immiscible liquid produced by distillation from plant material that is used in perfumes, cosmetics, incenses, and in medicine.
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Production
Raw plant material, consisting of the (flowers, leaves, stems, or roots, seeds, or seed peel, is put in an alembic over water, and the volatile compounds are vaporized. This is then put in a cooling tank and as the steam breaks down, the essential oil, which is lighter than steam, floats the upper portion of the cooled water. The water is referred to as the hydrosol, or plant water essence. Popular hydrosols are Rose Water, Lavender Water, and Orange Water. Most oils are distilled in a single process. The exception is ylang-ylang, which takes 22 hours to complete distillation. It is fractionally distilled, producing several grades.
Essential oil is always therapeutic grade until it is diluted with a carrier oil. Sweet almond oil, olive oil, hazelnut, and rosehip seed are examples of carrier oils. Since essential oils are so potent, many can irritate the skin unless diluted with a carrier oil. A home test to determine whether an oil is therapeutic grade is to place a drop on a coffee filter. Since the oil is a volatile substance, the oil will dissipate without leaving an oily residue on the paper.
Therapeutic grade is not a sole determination of quality. For example, Indian Sandalwood is considered more desirable than Australian Sandalwood, based upon the aroma; and is twice as costly, as Indian Sandalwood is endangered. Growing trend toward organic and wild harvested essential oils also effects the price and the quality.
Not all essential oils are distilled. Most citrus oils are expressed, or cold pressed from the peel. Some flowers contains very little oil and this requires a solvent is to extract the oil. The solvent dissolves the plant, and then alcohol is used to extract the essential oil from the rest of the plant material. Since the waxy covering of a jasmine petal is not alcohol soluble, it separates. The alcohol is removed by a second distillation, leaving behind the 'absolut. Hence, some essential oils such as jasmine and rose are labelled absolut.
Perfumery
Many essential oils are used in perfumery. The most well-known essential oil in perfumery is Rose, or Rose Absolut. Most production is harvested in Bulgaria and Morocco. Recently, China has begun cultivating Rose oil as well. It takes 6,000 pounds of rose petals to distill one ounce of essential oil. To mitigate the cost, Rose oil is often diluted with Geranium essential oil, at varying ratios of up to one drop of Rose to ten drops of Geranium. this is referred to as extending the Rose fragrance. Since Rose and Geranium are complementary, the extending process does not dilute the Rose fragrance dramatically.
Medicinal uses
Most essential oils have medicinal properties that have been applied in folk medicine since ancient times and are still widely used today. For example, most essential oils have antiseptic properties, though some are stronger than others. In addition, most have an uplifting effect on the mind, though different essential oils have different properties.
Popular oils
- Basil is used in perfumery for its clear, sweet and mildly spicy aroma. In aromatherapy, it is used for sharpening concentration, its uplifitng effect on depression, and to relieve headaches and migraines. Basil is an emmenagogue and should be avoided in pregnancy.
- Bergamot is one of the most popular oils in perfumery. It is an excellent insect repellent and may be helpful for both the urinary tract and for the digestive tract. It is useful for skin conditions linked to stress, such as cold sores, chicken pox, and herpes, especially when combined with Eucalyptus oil. Bergamot is a flavoring agent in Earl Grey tea.
- Black Pepper has a sharp and spicy aroma. Common uses include stimulating the circulation and for muscular aches and pains. Skin application is useful for bruises, since it stimulates the circulation.
- Citronella oil, obtained from lemongrass, is used in perfumery.
- Tea tree oil, leleshwa oil, sandalwood oil, and many other essential oils have topical (external) antimicrobial (i.e. antibacterial, antifungal, antiviral, or antiparasitic) activity and are used as antiseptics and disinfectants.
- Clove oil is a topical analgesic, especially useful in dentistry. It is also used an antiseptic, antispasmodic, carminativum, and antiemetic.
- Lavender oil is used as an antiseptic and for a number of other folk medicinal uses.
- Yarrow oil is used to reduce joint inflammation and relieve cold and influenza symptoms.
- Plai oil (a species of ginger) is also used for treating joint pain.
Aromatherapy is a form of alternative medicine, in which healing effects are ascribed to the smell of particular fragrances.
Prior to the discovery of distillation essential oils were extracted by pressing, and this is still the case in cultures such as Egypt. Traditional Egyptian practice involves pressing the flower and then burying it in unglazed ceramic vessels in the desert for a period of months to drive out water. The Lotus oil retaining its scent after 3000 years in alabaster vessels in Tutankhamun's tomb was pressed, rather than distilled.
Dangers
The smoke from burning essential oils may contain dangerous cancer producing products, such as polycyclic aromatic hydrocarbons (PAHs). The essential oils themselves are volatile organic compounds (VOCs). The use of essential oils should be avoided during pregnancy without consulting with a licensed professional, as some are aborticants.
Essential oils should not be applied directly to the skin due to their rapid absorption rate. Instead, essential oil should be applied with a carrier oil, such as olive, hazelnut, or any other "soft" oil. The ratio of essential oil disbursed in a carrier oil depends on its purpose.
While some advocate the ingestion of essential oils, this is generally not advisable.
Sources
- Allspice berry
- Almond
- Anise
- Celery seed
- Basil
- Bergamot
- Camphor
- Cedar wood
- Chamomile
- Cassia
- Citronella ; see also Lemon grass
- Cinnamon
- Clove
- Common sage
- Cumin
- Eucalyptus
- Frankincense
- Geranium
- Ginger
- Grapefruit
- Hyssop
- Jasmine
- Juniper berry
- Lavender
- Lemon
- Lemon grass see also Citronella
- Marjoram
- Melaleuca
- Myrrh
- Nutmeg oil
- Orange, blossoms and fruit peel
- Oregano
- Patchouli
- Peppermint
- Pine needle
- Rose
- Rosemary
- Rosewood
- Common sage
- Sandalwood
- Spearmint
- Tangerine
- Tea tree
- Thyme
- Wintergreen
- Witch hazel
- Ylang-ylang
References
Sellar, Wanda. The Directory of Essential Oils Essex: The C.W.Daniel Company, Ltd. Reprint, 2001. ISBN 0 85207 346 1
See also
External links
- Some dangerous oils (http://eethomp.com/AT/dangerous_oils.html)
- Global Essential Oils Crop Rotations Calendar (http://www.oilganic.com/essential-oil-crop-calendar-1armond.htm)
- [Distillation process of essential oils (http://www.wsu.edu/~gmhyde/433_web_pages/433Oil-web-pages/Processing/Process-Edible&Essence_Oil.html)]de:therisches l
eo:Volatila oleo he:שמן אתרי io:Esencala oleo ja:精油 nl:Etherische olie sv:Eteriska oljor