Essential oil

Last updated

An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the oil of the plant from which they were extracted, such as oil of clove. An essential oil 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. [1] The term "essential" used here does not mean indispensable or usable by the human body, as with the terms essential amino acid or essential fatty acid, which are so called because they are nutritionally required by a living organism. [2]

Contents

Essential oils are generally extracted by distillation, often by using steam. Other processes include expression, solvent extraction, sfumatura , absolute oil extraction, resin tapping, wax embedding, and cold pressing. They are used in perfumes, cosmetics, soaps, air fresheners and other products, for flavoring food and drink, and for adding scents to incense and household cleaning products.

Essential oils are often used for aromatherapy, a form of alternative medicine in which healing effects are ascribed to aromatic compounds. Aromatherapy may be useful to induce relaxation, but there is not sufficient evidence that essential oils can effectively treat any condition. [3] Improper use of essential oils may cause harm including allergic reactions, inflammation and skin irritation. Children may be particularly susceptible to the toxic effects of improper use. [4] [5] Essential oils can be poisonous if ingested or absorbed through the skin. [5]

Production

Distillation

Most common essential oils such as lavender, peppermint, tea tree oil, patchouli, and eucalyptus are distilled. Raw plant material, consisting of the flowers, leaves, wood, bark, roots, seeds, or peel, is put into an alembic (distillation apparatus) over water. As the water is heated, the steam passes through the plant material, vaporizing the volatile compounds. The vapors flow through a coil, where they condense back to liquid, which is then collected in the receiving vessel.

Most oils are distilled in a single process. One exception is ylang-ylang ( Cananga odorata ) which is purified through a fractional distillation.

The recondensed water is referred to as a hydrosol, hydrolat, herbal distillate, or plant water essence, which may be sold as another fragrant product. Hydrosols include rose water, lavender water, lemon balm, clary sage, and orange blossom water.

Expression

Most citrus peel oils are expressed mechanically or cold-pressed (similar to olive oil extraction). [6] Due to the relatively large quantities of oil in citrus peel and low cost to grow and harvest the raw materials, citrus-fruit oils are cheaper than most other essential oils. Lemon or sweet orange oils are obtained as byproducts of the citrus industry.

Before the discovery of distillation, all essential oils were extracted by pressing. [7]

Solvent extraction

Most flowers contain too little volatile oil to undergo expression, but their chemical components are too delicate and easily denatured by the high heat used in steam distillation. Instead, a solvent such as hexane or supercritical carbon dioxide is used to extract the oils. [8] Extracts from hexane and other hydrophobic solvents are called concretes , which are a mixture of essential oil, waxes, resins, and other lipophilic (oil-soluble) plant material.

Although highly fragrant, concretes contain large quantities of non-fragrant waxes and resins. Often, another solvent, such as ethyl alcohol, is used to extract the fragrant oil from the concrete. The alcohol solution is chilled to −18 °C (0 °F) for more than 48 hours which causes the waxes and lipids to precipitate out. The precipitates are then filtered out and the ethanol is removed from the remaining solution by evaporation, vacuum purge, or both, leaving behind the absolute .

Supercritical carbon dioxide is used as a solvent in supercritical fluid extraction. This method can avoid petrochemical residues in the product and the loss of some "top notes" when steam distillation is used. It does not yield an absolute directly. The supercritical carbon dioxide will extract both the waxes and the essential oils that make up the concrete. Subsequent processing with liquid carbon dioxide, achieved in the same extractor by merely lowering the extraction temperature, will separate the waxes from the essential oils. This lower temperature process prevents the decomposition and denaturing of compounds. When the extraction is complete, the pressure is reduced to ambient and the carbon dioxide reverts to a gas, leaving no residue.

Production quantities

Estimates of total production of essential oils are difficult to obtain. One estimate, compiled from data in 1989, 1990, and 1994 from various sources, gives the following total production, in tonnes, of essential oils for which more than 1,000 tonnes were produced. [9]

OilTonnes
Sweet orange 12,000
Mentha arvensis 4,800
Peppermint 3,200
Cedarwood 2,600
Lemon 2,300
Eucalyptus globulus 2,070
Litsea cubeba 2,000
Clove (leaf)2,000
Spearmint 1,300

Uses and cautions

Taken by mouth, many essential oils can be dangerous in high concentrations. Typical effects begin with a burning feeling, followed by salivation. [10] Different essential oils may have drastically different pharmacology. Some act as local anesthetic counterirritants and, thereby, exert an antitussive (cough suppressing) effect. [10] [11] Many essential oils, particularly tea tree oil, may cause contact dermatitis. [12] [13] [14] [15] Menthol and some others produce a feeling of cold followed by a sense of burning.

In Australia essential oils have been increasingly causing cases of poisoning, mostly of children. In the period 2014–2018 there were 4,412 poisoning incidents reported in New South Wales. [16]

Use in aromatherapy

Essential oils are used in aromatherapy as part of, for example, essential oil diffusers. Reed diffuser.jpg
Essential oils are used in aromatherapy as part of, for example, essential oil diffusers.

Aromatherapy is a form of alternative medicine in which healing effects are ascribed to the aromatic compounds in essential oils and other plant extracts. Aromatherapy may be useful to induce relaxation, but there is not sufficient evidence that essential oils can effectively treat any condition. [3] Scientific research indicates that essential oils cannot treat or cure any chronic disease or other illnesses. [3] Much of the research on the use of essential oils for health purposes has serious methodological errors. In a systemic review of 201 published studies on essential oils as alternative medicines, only 10 were found to be of acceptable methodological quality, and even these 10 were still weak in reference to scientific standards. [3] Use of essential oils may cause harm including allergic reactions and skin irritation; there has been at least one case of death. [4]

Use as pesticide

Research has shown that some essential oils have potential as a natural pesticide. In case studies, certain oils have been shown to have a variety of deterring effects on pests, specifically insects and select arthropods. [18] These effects may include repelling, inhibiting digestion, stunting growth, [19] decreasing rate of reproduction, or death of pests that consume the oil. However, the molecules within the oils that cause these effects are normally non-toxic for mammals. These specific actions of the molecules allow for widespread use of these "green" pesticides without harmful effects to anything else other than pests. [20] Essential oils that have been investigated include rose, lemon grass, lavender, thyme, peppermint, basil, and eucalyptus. [21]

Although they may not be the perfect replacement for all synthetic pesticides, essential oils have prospects for crop or indoor plant protection, urban pest control, [22] and marketed insect repellents, such as bug spray. Certain essential oils have been shown in studies to be comparable, if not exceeding, in effectiveness to DEET, which is currently marketed as the most effective mosquito repellent. Although essential oils are effective as pesticides when first applied in uses such as mosquito repellent applied to the skin, it is only effective in the vapor stage. Since this stage is relatively short-lived, creams and polymer mixtures are used in order to elongate the vapor period of effective repellency. [18]

In any form, using essential oils as green pesticides rather than synthetic pesticides has ecological benefits such as decreased residual actions. [21] In addition, increased use of essential oils as pest control could have not only ecological, but economical benefits as the essential oil market diversifies [20] and popularity increases among organic farmers and environmentally conscious consumers. [19] As of 2012 some EOs are authorized, and in use, in the European Union: Melaleuca oil as a fungicide, citronella oil as a herbicide, Syzygium aromaticum oil as a fungicide and bactericide, Mentha spicata oil as a plant growth regulator; Citrus sinensis oil (only in France) for Bemisia tabaci on Cucurbita pepo and Trialeurodes vaporariorum on Solanum lycopersicum ; and approvals for oils of Thymus , C. sinensis, and Tagetes as insecticides are pending. [19]

Use in food

In relation with their food applications, although these oils have been used throughout history as food preservatives, it was in the 20th century when EOs were considered as Generally Recognized as Safe (GRAS) by the Food and Drug Administration (FDA). [23]

GRAS substances according to the FDA [24]

Common nameBotanical name of plant source
Alfalfa Medicago sativa L.
Allspice Pimenta officinalis Lindl.
Bitter Almond, free from cyanide [25] Prunus amygdalus Batsch, Prunus armeniaca L., or Prunus persica (L.) Batsch.
Ambrette (seed)Hibiscus moschatus Moench.
Angelica root Angelica archangelica L.
Angelica seed Angelica archangelica L.
Angelica stem Angelica archangelica L.
Angostura (cusparia bark)Galipea officinalis Hancock, Angostura trifoliata
Anise Pimpinella anisum L.
Asafetida Ferula assa-foetida L. and related spp. of Ferula.
Balm (lemon balm)Melissa officinalis L.
Balsam of Peru Myroxylon pereirae Klotzsch.
Basil Ocimum basilicum L.
Bay leaves Laurus nobilis L.
Bay (myrcia oil) Pimenta racemosa (Mill.) J. W. Moore.
Bergamot (bergamot orange)Citrus aurantium L. subsp. bergamia Wright et Arn.
Bitter almond (free from prussic acid)Prunus amygdalus Batsch, Prunus armeniaca L., or Prunus persica (L.) Batsch.
Bois de rose Aniba rosaeodora Ducke.
Cacao Theobroma cacao L.
Camomile (chamomile) flowers, German or HungarianMatricaria chamomilla L.
Camomile (chamomile) flowers, Roman or EnglishAnthemis nobilis L.
Cananga Cananga odorata Hook. f. and Thoms.
Capsicum Capsicum frutescens L. and Capsicum annuum L.
Caraway Carum carvi L.
Cardamom seed (cardamon)Elettaria cardamomum Maton.
Carob bean Ceratonia siliqua L.
Carrot Daucus carota L.
Cascarilla bark Croton eluteria Benn.
Cassia bark, Chinese Cinnamomum cassia Blume.
Cassia bark, Padang or Batavia Cinnamomum burmanni Blume.
Cassia bark, Saigon Cinnamomum loureirii Nees.
Celery seed Apium graveolens L.
Cherry, wild, barkPrunus serotina Ehrh.
Chervil Anthriscus cerefolium (L.) Hoffm.
Chicory Cichorium intybus L.
Cinnamon bark, Ceylon Cinnamomum zeylanicum Nees.
Cinnamon bark, Chinese Cinnamomum cassia Blume.
Cinnamon bark, Saigon Cinnamomum loureirii Nees.
Cinnamon leaf, Ceylon Cinnamomum zeylanicum Nees.
Cinnamon leaf, ChineseCinnamomum cassia Blume.
Cinnamon leaf, SaigonCinnamomum loureirii Nees.
Citronella Cymbopogon nardus Rendle.
Citrus peels Citrus spp.
Clary (clary sage)Salvia sclarea L.
Clover Trifolium spp.
Coca (decocainized)Erythroxylum coca Lam. and other spp. of Erythroxylum.
Coffee Coffea spp.
Cola nut Cola acuminata Schott and Endl., and other spp. of Cola.
Coriander Coriandrum sativum L.
Cumin (cummin)Cuminum cyminum L.
Curaçao orange peel (orange, bitter peel)Citrus aurantium L.
Cusparia barkGalipea officinalis Hancock.
Dandelion Taraxacum officinale Weber and T. laevigatum DC.
Dandelion rootTaraxacum officinale Weber and T. laevigatum DC.
Dog grass (quackgrass, triticum)Agropyron repens (L.) Beauv.
Elder flowersSambucus canadensis L. and S. nigra I.
Estragole (esdragol, esdragon, tarragon)Artemisia dracunculus L.
Estragon (tarragon) Artemisia dracunculus L.
Fennel, sweetFoeniculum vulgare Mill.
Fenugreek Trigonella foenum-graecum L.
Galanga (galangal)Alpinia officinarum Hance.
Geranium Pelargonium spp.
Geranium, East IndianCymbopogon martini Stapf.
Geranium, rosePelargonium graveolens L'Her.
Ginger Zingiber officinale Rosc.
Grapefruit Citrus paradisi Macf.
Guava Psidium spp.
Hickory barkCarya spp.
Horehound (hoarhound)Marrubium vulgare L.
Hops Humulus lupulus L.
Horsemint Monarda punctata L.
Hyssop Hyssopus officinalis L.
Immortelle Helichrysum augustifolium DC.
Jasmine Jasminum officinale L. and other spp. of Jasminum.
Juniper (berries)Juniperus communis L.
Kola nut Cola acuminata Schott and Endl., and other spp. of Cola.
Laurel berriesLaurus nobilis L.
Laurel leavesLaurus spp.
Lavender Lavandula officinalis Chaix.
Lavender, spikeLavandula latifolia Vill.
Lavandin Hybrids between Lavandula officinalis Chaix and Lavandula latifolin Vill.
Lemon Citrus limon (L.) Burm. f.
Lemon balm (see balm)Melissa officinalis L.
Lemongrass Cymbopogon citratus DC. and Cymbopogon lexuosus Stapf.
Lemon peelCitrus limon (L.) Burm. f.
Lime Citrus aurantifolia Swingle.
Linden flowersTilia spp.
Locust bean Ceratonia siliqua L,
Lupulin Humulus lupulus L.
Mace Myristica fragrans Houtt.
MandarinCitrus reticulata Blanco.
Marjoram, sweetMajorana hortensis Moench.
Yerba Mate Ilex paraguariensis St. Hil.
Melissa (see balm)
Menthol Mentha spp.
Menthyl acetate Do.
Molasses (extract)Saccharum officinarum L.
Mustard Brassica spp.
Naringin Citrus paradisi Macf.
Neroli, bigarade Citrus aurantium L.
Nutmeg Myristica fragrans Houtt.
Onion Allium cepa L.
Orange, bitter, flowersCitrus aurantium L.
Orange, bitter, peelDo.
Orange leafCitrus sinensis (L.) Osbeck.
Orange, sweetDo.
Orange, sweet, flowersDo.
Orange, sweet, peelDo.
Origanum Origanum spp.
Palmarosa Cymbopogon martini Stapf.
Paprika Capsicum annuum L.
Parsley Petroselinum crispum (Mill.) Mansf.
Pepper, black Piper nigrum L.
Pepper, whiteDo.
Peppermint Mentha piperita L.
Peruvian balsam Myroxylon pereirae Klotzsch.
Petitgrain Citrus aurantium L.
Petitgrain lemonCitrus limon (L.) Burm. f.
Petitgrain mandarin or tangerineCitrus reticulata Blanco.
Pimenta Pimenta officinalis Lindl.
Pimenta leaf Pimenta officinalis Lindl.
Pipsissewa leaves Chimaphila umbellata Nutt.
Pomegranate Punica granatum L.
Prickly ash bark Xanthoxylum (or Zanthoxylum) Americanum Mill. or Xanthoxylum clava-herculis L.
Rose absoluteRosa alba L., Rosa centifolia L., Rosa damascena Mill., Rosa gallica L., and vars. of these spp.
Rose (otto of roses, attar of roses)Do.
Rose budsDo.
Rose flowersDo.
Rose fruit (hips)Do.
Rose geraniumPelargonium graveolens L'Her.
Rose leavesRosa spp.
Rosemary Rosmarinus officinalis L.
Saffron Crocus sativus L.
Sage Salvia officinalis L.
Sage, GreekSalvia triloba L.
Sage, Spanish Salvia lavandulaefolia Vahl.
St. John's bread Ceratonia siliqua L.
Savory, summer Satureia hortensis L.
Savory, winterSatureia montana L.
Schinus molle Schinus molle L.
Sloe berries (blackthorn berries)Prunus spinosa L.
Spearmint Mentha spicata L.
Spike lavender Lavandula latifolia Vill.
Tamarind Tamarindus indica L.
Tangerine Citrus reticulata Blanco.
Tarragon Artemisia dracunculus L.
Tea Thea sinensis L.
Thyme Thymus vulgaris L. and Thymus zygis var. gracilis Boiss.
Thyme, whiteDo.
Thyme, wild or creepingThymus serpyllum L.
Triticum (see dog grass)Elymus repens
Tuberose Polianthes tuberosa L.
Turmeric Curcuma longa L.
Vanilla Vanilla planifolia Andr. or Vanilla tahitensis J. W. Moore.
Violet flowers Viola odorata L.
Violet leaves Viola odorata L.
Violet leaves absolute Viola odorata L.
Wild cherry bark Prunus serotina Ehrh.
Ylang-ylang Cananga odorata Hook. f. and Thoms.
Zedoary bark Curcuma zedoaria Rosc.

As antimicrobials

The most commonly used essential oils with antimicrobial action are: β-caryophyllene, eugenol, eugenol acetate, carvacrol, linalool, thymol, geraniol, geranyl acetate, bicyclogermacrene, cinnamaldehyde, geranial, neral, 1,8-cineole, methyl chavicol, methyl cinnamate, methyl eugenol, camphor, α-thujone, viridiflorol, limonene, (Z)-linalool oxide, α-pinene, p-cymene, (E)-caryophyllene, γ-terpinene. [26]

Some essential oils are effective antimicrobials and have been evaluated for food incorporation in vitro. However, actual deployment is rare because much higher concentrations are required in real foods. Some or all of this lower effectiveness is due to large differences between culture medium and foods in: chemistry (especially lipid content), viscosity, and duration of inoculation/storage. [26]

Dilution

Essential oils are usually lipophilic (literally: "oil-loving") compounds that are immiscible (not miscible) with water. They can be diluted in solvents like pure ethanol and polyethylene glycol.[ citation needed ]

Raw materials

Essential oils are derived from sections of plants. Some plants, like the bitter orange, are sources of several types of essential oil.

Bark
Berries
Flowers
Leaves
Peel
Resin
Rhizome
Roots
Seeds
Woods

Balsam of Peru

Balsam of Peru, an essential oil derived from Myroxylon plants, is used in food and drink for flavoring, in perfumes and toiletries for fragrance, and in animal care products. [27] However, national and international surveys identified balsam of Peru among the "top five" allergens most commonly causing patch test allergic reactions in people referred to dermatology clinics. [28] [29] [30]

Garlic oil

Garlic oil is an essential oil derived from garlic. [31]

Eucalyptus oil

Most eucalyptus oil on the market is produced from the leaves of Eucalyptus globulus. Steam-distilled eucalyptus oil is used throughout Asia, Africa, Latin America and South America as a primary cleaning/disinfecting agent added to soaped mop and countertop cleaning solutions; it also possesses insect and limited vermin control properties. [32] Note, however, there are hundreds of species of eucalyptus, and perhaps some dozens are used to various extents as sources of essential oils. Not only do the products of different species differ greatly in characteristics and effects, but also the products of the very same tree can vary grossly. [33]

Lavender oil

Lavender essential oil sold at a market in France Marches des Producteurs de Pays 11 16 14.jpg
Lavender essential oil sold at a market in France

Lavender oil has long been used in the production of perfume. [34] However, studies have shown it can be estrogenic and antiandrogenic, causing problems for prepubescent boys and pregnant women, in particular. [35] Lavender essential oil is also used as an insect repellent. [36]

Rose oil

Rose oil is produced from the petals of Rosa damascena and Rosa centifolia . Steam-distilled rose oil is known as "rose otto", while the solvent extracted product is known as "rose absolute".

Toxicity

The potential toxicity of essential oil is related to its level or grade of purity, and to the toxicity of specific chemical components of the oil. [5] Many essential oils are designed exclusively for their aroma-therapeutic quality; these essential oils generally should not be applied directly to the skin in their undiluted form. [5] Some can cause severe irritation, provoke an allergic reaction and, over time, prove toxic to the liver. If ingested or rubbed into the skin, essential oils can be highly poisonous, causing confusion, choking, loss of muscle coordination, difficulty in breathing, pneumonia, seizures, and possibly severe allergic reactions or coma. [5]

Some essential oils, including many of the citrus peel oils, are photosensitizers, increasing vulnerability of the skin to sunlight. [37]

Industrial users of essential oils should consult the safety data sheets to determine the hazards and handling requirements of particular oils. [5] Even certain therapeutic-grade oils can pose potential threats to individuals with epilepsy or pregnant women.

Essential oil use in children can pose a danger when misused because of their thin skin and immature livers. This might cause them to be more susceptible to toxic effects than adults. [5]

Flammability

The flash point of each essential oil is different. Many of the common essential oils, such as tea tree, lavender, and citrus oils, are classed as Class 3 Flammable Liquids, as they have a flash point of 50–60 °C.

Gynecomastia

Estrogenic and antiandrogenic activity have been reported by in vitro study of tea tree oil and lavender essential oils. Two published sets of case reports suggest that lavender oil may be implicated in some cases of gynecomastia, an abnormal breast tissue growth in prepubescent boys. [38] [39] The European Commission's Scientific Committee on Consumer Safety dismissed the claims against tea tree oil as implausible, but did not comment on lavender oil. [40] In 2018, a BBC report on a study stated that tea tree and lavender oils contain eight substances that when tested in tissue culture experiments, increasing the level of estrogen and decreasing the level of testosterone. Some of the substances are found in "at least 65 other essential oils". The study did not include animal or human testing. [41]

Handling

Exposure to essential oils may cause contact dermatitis. [13] [14] [15] Essential oils can be aggressive toward rubbers and plastics, so care must be taken in choosing the correct handling equipment. Glass syringes are often used, but have coarse volumetric graduations. Chemistry syringes are ideal, as they resist essential oils, are long enough to enter deep vessels, and have fine graduations, facilitating quality control. Unlike traditional pipettes, which have difficulty handling viscous fluids, the chemistry syringe, also known as a positive displacement pipette, has a seal and piston arrangement which slides inside the pipette, wiping the essential oil off the pipette wall.

Ingestion

Some essential oils qualify as GRAS flavoring agents for use in foods, beverages, and confectioneries according to strict good manufacturing practice and flavorist standards. [24] Pharmacopoeia standards for medicinal oils should be heeded. Some oils can be toxic to some domestic animals, cats in particular. [42] The internal use of essential oils can pose hazards to pregnant women, as some can be abortifacients in dose 0.5–10 mL, and thus should not be used during pregnancy.[ citation needed ]

Pesticide residues

Concern about pesticide residues in essential oils, particularly those used therapeutically, means many practitioners of aromatherapy buy organically produced oils. Not only are pesticides present in trace quantities, but also the oils themselves are used in tiny quantities and usually in high dilutions. Where there is a concern about pesticide residues in food essential oils, such as mint or orange oils, the proper criterion is not solely whether the material is organically produced, but whether it meets the government standards based on actual analysis of its pesticide content. [43]

Pregnancy

Some essential oils may contain impurities and additives that may be harmful to pregnant women. [44] Certain essential oils are safe to use during pregnancy, but care must be taken when selecting quality and brand. Sensitivity to certain smells may cause pregnant women to have adverse side effects with essential oil use, such as headache, vertigo, and nausea. Pregnant women often report an abnormal sensitivity to smells and taste, [45] and essential oils can cause irritation and nausea when ingested. [5]

Toxicology

The following table lists the LD50 or median lethal dose for common oils; this is the dose required to kill half the members of a tested animal population. LD50 is intended as a guideline only, and reported values can vary widely due to differences in tested species and testing conditions. [46]

Common NameOral LD50Dermal LD50Notes
Neem14 g/kg>2 g/kg
Lemon myrtle2.43 g/kg2.25 g/kg
Frankincense>5 g/kg>5 g/kgBoswellia carterii
Frankincense>2 g/kg>2 g/kgBoswellia sacra
Indian frankincense>2 g/kg>2 g/kgBoswellia serrata
Ylang-ylang>5 g/kg>5 g/kg
Cedarwood>5 g/kg>5 g/kg
Roman chamomile>5 g/kg>5 g/kg
White camphor>5 g/kg>5 g/kgCinnamomum camphora, extracted from leaves
Yellow camphor3.73 g/kg>5 g/kgCinnamomum camphora, extracted from bark
Hot oil3.80 g/kg>5 g/kgCinnamomum camphora, oil extracted from leaves
Cassia2.80 g/kg0.32 g/kg

Standardization of derived products

In 2002, ISO published ISO 4720 in which the botanical names of the relevant plants are standardized. [47] The rest of the standards with regards to this topic can be found in the section of ICS 71.100.60 [48]

History

The resins of aromatics and plant extracts were retained to produce traditional medicines and scented preparations, such as perfumes and incense, including frankincense, myrrh, cedarwood, juniper berry and cinnamon in ancient Egypt may have contained essential oils. [49] [50] In 1923, when archaeologists opened Pharaoh Tutankhamun’s tomb, they found 50 alabaster jars of essential oils. [50] [ dubious ]

Essential oils have been used in folk medicine over centuries. The Persian physician Ibn Sina, known as Avicenna in Europe, was first to derive the fragrance of flowers from distillation, [51] while the earliest recorded mention of the techniques and methods used to produce essential oils may be Ibn al-Baitar (1188–1248), an Arab Al-Andalusian (Muslim Spain) physician, pharmacist and chemist. [52]

Rather than refer to essential oils themselves, modern works typically discuss specific chemical compounds of which the essential oils are composed, such as referring to methyl salicylate rather than "oil of wintergreen". [53] [54]

Essential oils are used in aromatherapy, a branch of alternative medicine that uses essential oils and other aromatic compounds. [55] Oils are volatilized, diluted in a carrier oil and used in massage, diffused in the air by a nebulizer or diffuser, heated over a candle flame, or burned as incense.

See also

Related Research Articles

<i>Cymbopogon</i> Genus of grasses

Cymbopogon, also known as lemongrass, barbed wire grass, silky heads, Cochin grass, Malabar grass, oily heads, citronella grass or fever grass, is a genus of Asian, African, Australian, and tropical island plants in the grass family. Some species are commonly cultivated as culinary and medicinal herbs because of their scent, resembling that of lemons . The name cymbopogon derives from the Greek words kymbe and pogon "which mean [that] in most species, the hairy spikelets project from boat-shaped spathes." Lemongrass and its oil are believed to possess therapeutic properties.

<span class="mw-page-title-main">Lavender oil</span> Essential oil distilled from lavender flower spikes

Lavender oil is an essential oil obtained by distillation from the flower spikes of certain species of lavender. There are over 400 types of lavender worldwide with different scents and qualities. Two forms of lavender oil are distinguished, lavender flower oil, a colorless oil, insoluble in water, having a density of 0.885 g/mL; and lavender spike oil, a distillate from the herb Lavandula latifolia, having a density of 0.905 g/mL. Like all essential oils, it is not a pure compound; it is a complex mixture of phytochemicals, including linalool and linalyl acetate.

<span class="mw-page-title-main">Tea tree oil</span> Essential oil derived from leaves

Tea tree oil, also known as melaleuca oil, is an essential oil with a fresh camphoraceous odor and a colour that ranges from pale yellow to nearly colourless and clear. It is derived from the leaves of the tea tree, Melaleuca alternifolia, native to southeast Queensland and the northeast coast of New South Wales, Australia. The oil comprises many constituent chemicals and its composition changes if it is exposed to air and oxidizes.

<span class="mw-page-title-main">Absolute (perfumery)</span>

Used in perfumery and aromatherapy, absolutes are similar to essential oils. They are concentrated, highly aromatic, oily mixtures extracted from plants. Whereas essential oils are produced by distillation, boiling or pressing, absolutes are produced through solvent extraction, or more traditionally, through enfleurage.

<span class="mw-page-title-main">Insect repellent</span> Substance which repels insects

An insect repellent is a substance applied to skin, clothing, or other surfaces to discourage insects from landing or climbing on that surface. Insect repellents help prevent and control the outbreak of insect-borne diseases such as malaria, Lyme disease, dengue fever, bubonic plague, river blindness, and West Nile fever. Pest animals commonly serving as vectors for disease include insects such as flea, fly, and mosquito; and ticks (arachnids).

<span class="mw-page-title-main">Neroli</span> Essential oil of the bitter orange blossom

Neroli oil is an essential oil produced from the blossom of the bitter orange tree. Its scent is sweet, honeyed and somewhat metallic with green and spicy facets. Orange blossom is also extracted from the same blossom and both extracts are extensively used in perfumery. Orange blossom can be described as smelling sweeter, warmer and more floral than neroli. The difference between how neroli and orange blossom smell and why they are referred to with different names, is a result of the process of extraction that is used to obtain the oil from the blooms. Neroli is extracted by steam distillation and orange blossom is extracted via a process of enfleurage or solvent extraction.

<span class="mw-page-title-main">Pinene</span> Oily organic chemical found in plants

Pinene is a collection of unsaturated bicyclic monoterpenes. Two geometric isomers of pinene are found in nature, α-pinene and β-pinene. Both are chiral. As the name suggests, pinenes are found in pines. Specifically, pinene is the major component of the liquid extracts of conifers. Pinenes are also found in many non-coniferous plants such as camphorweed (Heterotheca) and big sagebrush.

<span class="mw-page-title-main">Cajeput tree</span> Common name for several species of tree

Cajeput tree is a common name used for certain classification of tree that has a white spongy bark that is flexible and can easily flake off the trunk. The Cajeput tree is of the genus Melaleuca, native to Australia and is commonly known in North America as the tea tree. The name "Cajeput tree" is primarily used for the species M. cajuputi, M. leucadendra, M. linariifolia, M. viridiflora and M. quinquenervia. Other names for these trees are the paperbark tree, punk tree, or the white bottle brush tree. Similar subtropical trees from the eucalyptus family are evergreens with pointed leaves and white, red or green flowers.

<span class="mw-page-title-main">Cajeput oil</span>

Cajuput oil is a volatile oil obtained by distillation from the leaves of the myrtaceous trees Melaleuca leucadendra, Melaleuca cajuputi, and probably other Melaleuca species. The trees yielding the oil are found throughout Maritime Southeast Asia and over the hotter parts of the Australian continent. The majority of the oil is produced on the Indonesian island of Sulawesi. The name "cajeput" is derived from its Malay name, kayu putih or "white wood".

<span class="mw-page-title-main">Eucalyptol</span> Chemical compound

Eucalyptol is a monoterpenoid. A colorless liquid, it is a bicyclic ether. Eucalyptol has a fresh mint-like smell and a spicy, cooling taste. It is insoluble in water, but miscible with organic solvents. Eucalyptol makes up ~70% - 90% of eucalyptus oil. Eucalyptol forms crystalline adducts with hydrohalic acids, o-cresol, resorcinol, and phosphoric acid. Formation of these adducts is useful for purification.

<span class="mw-page-title-main">Orange oil</span> Essential oil produced in rind of oranges

Orange oil is an essential oil produced by cells within the rind of an orange fruit. In contrast to most essential oils, it is extracted as a by-product of orange juice production by centrifugation, producing a cold-pressed oil. It is composed of mostly d-limonene, and is often used in place of pure d-limonene. D-limonene can be extracted from the oil by distillation.

Peppermint extract is an herbal extract of peppermint made from the essential oils of peppermint leaves. Peppermint is a hybrid of water mint and spearmint and was indigenous to Europe and the Middle East before it became common in other regions, such as North America and Asia.

<span class="mw-page-title-main">Extract</span> Category of substance

An extract is a substance made by extracting a part of a raw material, often by using a solvent such as ethanol, oil or water. Extracts may be sold as tinctures, absolutes or in powder form.

<span class="mw-page-title-main">Infusion</span> Process of extracting chemical compounds or flavors from plant material in a solvent

Infusion is the process of extracting chemical compounds or flavors from plant material in a solvent such as water, oil or alcohol, by allowing the material to remain suspended in the solvent over time. An infusion is also the name for the resultant liquid. The process of infusion is distinct from both decoction—a method of extraction involving boiling the plant material—and percolation, in which water is passed through the material.

<span class="mw-page-title-main">Verbenone</span> Chemical compound

Verbenone is a natural organic compound classified as a terpene that is found naturally in a variety of plants. The chemical has a pleasant characteristic odor. Besides being a natural constituent of plants, it and its analogs are insect pheromones. In particular, verbenone when formulated in a long-lasting matrix has an important role in the control of bark beetles such as the mountain pine beetle and the Southern pine bark beetle.

<span class="mw-page-title-main">Eucalyptus oil</span> Distilled oil from the leaf of Eucalyptus

Eucalyptus oil is the generic name for distilled oil from the leaf of Eucalyptus, a genus of the plant family Myrtaceae native to Australia and cultivated worldwide. Eucalyptus oil has a history of wide application, as a pharmaceutical, antiseptic, repellent, flavouring, fragrance and industrial uses. The leaves of selected Eucalyptus species are steam distilled to extract eucalyptus oil.

<span class="mw-page-title-main">Fragrance extraction</span> Separation process of aromatic compounds from raw materials

Fragrance extraction refers to the separation process of aromatic compounds from raw materials, using methods such as distillation, solvent extraction, expression, sieving, or enfleurage. The results of the extracts are either essential oils, absolutes, concretes, or butters, depending on the amount of waxes in the extracted product.

<span class="mw-page-title-main">Aromatherapy</span> Pseudo-scientific alternative medicine practice

Aromatherapy is based on the usage of aromatic materials including essential oils and other aroma compounds, with claims for improving psychological and physical well-being. It is offered as a complementary therapy or as a form of alternative medicine, the first meaning alongside standard treatments, the second instead of conventional, evidence-based treatments.

<span class="mw-page-title-main">Bergamot essential oil</span> Cold-pressed essential oil

Bergamot essential oil is a cold-pressed essential oil produced by cells inside the rind of a bergamot orange fruit. It is a common flavoring and top note in perfumes. The scent of bergamot essential oil is similar to a sweet light orange peel oil with a floral note.

References

  1. "essential oil". Oxford English Dictionary (online, American English ed.). Archived from the original on 2014-08-09. Retrieved 2014-07-21.
  2. Reeds, P. J. (2000). "Dispensable and indispensable amino acids for humans". The Journal of Nutrition. 130 (7): 1835S–40S. doi: 10.1093/jn/130.7.1835S . PMID   10867060.
  3. 1 2 3 4 Lee, Myeong Soo; Choi, Jiae Choi (2012). "Aromatherapy for health care: an overview of systematic reviews". Maturitas. 3 (71): 257–260. doi:10.1016/j.maturitas.2011.12.018. PMID   22285469.
  4. 1 2 Posadzki, P; Alotaibi, A; Ernst, E (2012). "Adverse effects of aromatherapy: A systematic review of case reports and case series". The International Journal of Risk & Safety in Medicine. 24 (3): 147–61. doi:10.3233/JRS-2012-0568. PMID   22936057.
  5. 1 2 3 4 5 6 7 8 "Essential oils: Poisonous when misused". US National Capital Poison Center. Retrieved 2017-12-01.
  6. Shutes, Jade. "How Are Essential Oils Extracted?". NAHA- National Association for Holistic Aromatherapy. Archived from the original on 11 June 2013. Retrieved 16 June 2019.
  7. Ryman, Daniele (1984). The Aromatherapy Handbook: The Secret Healing Power Of Essential Oils. Century Publishing CO. Ltd. pp. Chapter 3. ISBN   9780852072158.
  8. Aizpurua-Olaizola, Oier; Ormazabal, Markel; Vallejo, Asier; Olivares, Maitane; Navarro, Patricia; Etxebarria, Nestor; Usobiaga, Aresatz (2015-01-01). "Optimization of supercritical fluid consecutive extractions of fatty acids and polyphenols from Vitis vinifera grape wastes". Journal of Food Science. 80 (1): E101–107. doi:10.1111/1750-3841.12715. ISSN   1750-3841. PMID   25471637.
  9. "ISO TC 54 Business Plan – Essential oils" (PDF). Retrieved 2006-09-14. It is unclear from the source what period of time the quoted figures include.
  10. 1 2 Sapeika, Norman (1963). Actions and Uses of Drugs. A.A. Balkema.[ page needed ]
  11. Haneke, Karen E (February 2002), Turpentine (Turpentine Oil, Wood Turpentine, Sulfate Turpentine, Sulfite Turpentine) [8006-64-2]: Review of Toxicological Literature (PDF), National Institute of Environmental Health Sciences [ page needed ]
  12. Larson, David; Jacob, Sharon E. (2012). "Tea Tree Oil". Dermatitis. 23 (1): 48–9. doi:10.1097/DER.0b013e31823e202d. PMID   22653070.
  13. 1 2 Trattner, Akiva; David, Michael; Lazarov, Aneta (2008). "Occupational contact dermatitis due to essential oils". Contact Dermatitis. 58 (5): 282–4. doi:10.1111/j.1600-0536.2007.01275.x. PMID   18416758. S2CID   10674102.
  14. 1 2 Bleasel, Narelle; Tate, Bruce; Rademaker, Marius (2002). "Allergic contact dermatitis following exposure to essential oils". Australasian Journal of Dermatology. 43 (3): 211–3. doi:10.1046/j.1440-0960.2002.00598.x. PMID   12121401. S2CID   46674505.
  15. 1 2 Isaksson, M; Brandão, F. M.; Bruze, M; Goossens, A (2000). "Short Communications". Contact Dermatitis. 43 (1): 41–2. doi:10.1034/j.1600-0536.2000.043001041.x. PMID   10902588. S2CID   221576846.
  16. Lee KA, Harnett JE, Cairns R (2019). "Essential oil exposures in Australia: analysis of cases reported to the NSW Poisons Information Centre". Medical Journal of Australia. 212 (3): 132–133. doi:10.5694/mja2.50403. ISSN   0025-729X. PMID   31709543. S2CID   207940224.
  17. "Aromatherapy: The Best Essential Oil Diffuser". simplerandsmarter.com.au. Retrieved 2016-05-15.
  18. 1 2 Nerio, Luz Stella; Olivero-Verbel, Jesus; Stashenko, Elena (2010-01-01). "Repellent activity of essential oils: A review". Bioresource Technology. 101 (1): 372–378. doi:10.1016/j.biortech.2009.07.048. ISSN   0960-8524. PMID   19729299.
  19. 1 2 3 Regnault-Roger, Catherine; Vincent, Charles; Arnason, John Thor (2012-01-07). "Essential Oils in Insect Control: Low-Risk Products in a High-Stakes World". Annual Review of Entomology . 57 (1): 405–424. doi:10.1146/annurev-ento-120710-100554. ISSN   0066-4170. PMID   21942843.
  20. 1 2 Regnault-Roger, Catherine (1997-02-01). "The potential of botanical essential oils for insect pest control". Integrated Pest Management Reviews. 2 (1): 25–34. doi:10.1023/A:1018472227889. ISSN   1353-5226. S2CID   39007186.
  21. 1 2 Koul, Opender; Suresh, Walia; Dhaliwal, G. S. (2008). "Essential Oils as Green Pesticides: Potential and Constraints". Biopesticides International. 4 (1): 63–84. S2CID   85741148.
  22. Isman, Murray B (2000-09-12). "Plant essential oils for pest and disease management". Crop Protection. 19 (8–10): 603–608. doi:10.1016/S0261-2194(00)00079-X. ISSN   0261-2194.
  23. Preedy VR (2015-09-28). Essential oils in food preservation, flavor and safety. Amsterdam. ISBN   9780124166448. OCLC   922581414.
  24. 1 2 "CFR - Code of Federal Regulations Title 21". www.accessdata.fda.gov. Retrieved 2018-12-08.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  25. "Wieviel Prozent Blausäure enthält natürliches Bittermandelöl?".
  26. 1 2 Rao, Jiajia; Chen, Bingcan; McClements, David Julian (2019-03-25). "Improving the Efficacy of Essential Oils as Antimicrobials in Foods: Mechanisms of Action". Annual Review of Food Science and Technology . 10 (1): 365–387. doi:10.1146/annurev-food-032818-121727. ISSN   1941-1413. PMID   30653350. S2CID   58656780.
  27. "Balsam of Peru". go.drugbank.com. DrugBank. 11 December 2021. Retrieved 2021-12-15.
  28. Arenholt-Bindslev, D; Jolanki, R; Kanerva, L (2008). "Diagnosis of Side Effects of Dental Materials, with Special Emphasis on Delayed and Immediate Allergic Reactions". In Schmalz, Gottfried; Arenholt-Bindslev, Dorthe (eds.). Biocompatibility of Dental Materials. Springer. p. 352. doi:10.1007/978-3-540-77782-3_14. ISBN   9783540777823. Archived from the original on May 18, 2016. Retrieved March 5, 2014.
  29. Habif, Thomas P. (2009). Clinical Dermatology. Elsevier Health Sciences. ISBN   9780323080378 . Retrieved March 6, 2014.
  30. Yiannias, JA (2013). "Contact Dermatitis". In Bope, Edward T.; Kellerman, Rick D. (eds.). Conn's Current Therapy 2014: Expert Consult. Elsevier Health Sciences. ISBN   9780323225724.
  31. Linskens, H.F.; Adams, R.P.; Crespo, M.E.; Jackson, J.F.; Deans, S.G.; Dobson, H.E.M.; Dunlop, P.; Erdelmeier, C.A.J.; Ghosh, A.; Hammond, E.G. (2012). Essential Oils and Waxes. Molecular Methods of Plant Analysis. Springer Berlin Heidelberg. p. 105. ISBN   978-3-642-84023-4 . Retrieved December 29, 2017.
  32. Batish, Daizy R.; Singh, Harminder Pal; Kohlia, Ravinder Kumar; Kaur, Shalinder (10 December 2008). "Eucalyptus essential oil as a natural pesticide". Forest Ecology and Management. 256 (12): 2166–2174. doi:10.1016/j.foreco.2008.08.008.
  33. Thorpe's Dictionary of Applied Chemistry. Vol. 8 (4th ed.). Longmans Green. 1947.[ page needed ]
  34. N. Groom. New Perfume Handbook. Springer Science & Business Media, 1997 ISBN   9780751404036, pp. 184-186
  35. Henley, Derek V; Lipson, Natasha; Korach, Kenneth S; Bloch, Clifford A (2007). "Prepubertal Gynecomastia Linked to Lavender and Tea Tree Oils". New England Journal of Medicine. 356 (5): 479–485. doi:10.1056/NEJMoa064725. PMID   17267908.
  36. Debboun, Mustapha; Frances, Stephen P.; Strickman, Daniel, eds. (2014). Insect Repellents Handbook (2nd ed.). CRC Press. p. 362. ISBN   978-1466553552.
  37. Kaddu, Steven; Kerl, Helmut; Wolf, Peter (2001). "Accidental bullous phototoxic reactions to bergamot aromatherapy oil". Journal of the American Academy of Dermatology. 45 (3): 458–61. doi:10.1067/mjd.2001.116226. PMID   11511848.
  38. Henley, Derek V.; Lipson, Natasha; Korach, Kenneth S.; Bloch, Clifford A. (2007). "Prepubertal Gynecomastia Linked to Lavender and Tea Tree Oils". New England Journal of Medicine. 356 (5): 479–85. doi:10.1056/NEJMoa064725. PMID   17267908.
  39. Diaz A, Luque L, Badar Z, Kornic S, Danon M (2016). "Prepubertal gynecomastia and chronic lavender exposure: report of three cases". J. Pediatr. Endocrinol. Metab. 29 (1): 103–107. doi:10.1515/jpem-2015-0248. PMID   26353172. S2CID   19454282.
  40. Scientific Committee on Consumer Products (December 16, 2008), Opinion on tea tree oil (PDF), Directorate-General for Health and Consumers: European Commission: European Union
  41. "More evidence essential oils 'make male breasts develop'". BBC News. BBC. 18 March 2018. Retrieved 18 March 2018. A suspected link between abnormal breast growth in young boys and the use of lavender and tea tree oils has been given new weight, after a study found eight chemicals contained in the oils interfere with hormones.
  42. Bischoff, K.; Guale, Fessesswork (1998). "Australian Tea Tree (Melaleuca Alternifolia) Oil Poisoning in Three Purebred Cats". Journal of Veterinary Diagnostic Investigation. 10 (2): 208–10. doi: 10.1177/104063879801000223 . PMID   9576358.
  43. Menary, RC (2008). Minimising pesticide residues in essential oils. Rural Industries Research and Development Corporation. ISBN   9781741517095.[ page needed ]
  44. "Management of severe nausea and vomiting in pregnant women". Clinical Pharmacist. 2013. doi:10.1211/cp.2013.11131205. ISSN   2053-6178.
  45. Nordin, S.; Broman, D. A.; Olofsson, J. K.; Wulff, M (2004). "A Longitudinal Descriptive Study of Self-reported Abnormal Smell and Taste Perception in Pregnant Women". Chemical Senses. 29 (5): 391–402. doi: 10.1093/chemse/bjh040 . PMID   15201206.
  46. Dweck, AC (September 2009). "Toxicology of essential oils reviewed" (PDF). Personal Care. Archived from the original (PDF) on 2011-07-18. Retrieved 2011-01-05.
  47. International Organization for Standardization. "ISO 4720:2002 Essential oils – Nomenclature" . Retrieved April 23, 2009.
  48. International Organization for Standardization. "71.100.60: Essential oils" . Retrieved June 14, 2009.
  49. K. Husnu Can Baser; Gerhard Buchbauer (28 December 2009). Handbook of Essential Oils: Science, Technology, and Applications. CRC Press. ISBN   978-1-4200-6316-5.
  50. 1 2 Jordan Rubin (17 January 2017). Essential Oils: Ancient Medicine for a Modern World. Destiny Image Publishers. ISBN   978-0-7684-1188-1.
  51. Essa, Ahmed; Ali, Othman (2010). Studies in Islamic Civilization: The Muslim Contribution to the Renaissance. International Institute of Islamic Thought (IIIT). p. 70. ISBN   9781565643505.
  52. Houtsma, M.Th. (1993). E. J. Brill's First Encyclopaedia of Islam, 1913–1936. Vol. 4. Brill. pp. 1011–. ISBN   978-90-04-09790-2.
  53. Gilman, A. G.; Rall, T. W.; Nies, Alan S.; Taylor, Palmer, eds. (1990). Goodman & Gilman's The Pharmacological Basis of Therapeutics (8th ed.). New York: Pergamon. ISBN   978-0-08-040296-3.[ page needed ]
  54. Klaassen, Curtis D.; Amdur, Mary O.; Casarett, Louis J.; Doull, John (1991). Casarett and Doull's Toxicology: The Basic Science of Poisons. New York: McGraw-Hill. ISBN   978-0071052399.[ page needed ]
  55. "Aromatherapy: Uses, benefits, oils, and risks". www.medicalnewstoday.com. 2017-03-20. Retrieved 2022-02-16.

Further reading