Essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants.
Essential oils are often used for aromatherapy, a form of alternative medicine in which healing effects are ascribed to aromatic compounds.
[3] Improper use of essential oils may cause harm including allergic reactions, inflammation and skin irritation.
Raw plant material, consisting of the flowers, leaves, wood, bark, roots, seeds, or peel, is put into an alembic (distillation apparatus) over water.
[7] 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.
[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.
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.
[16] Aromatherapy is a form of alternative medicine in which healing effects are ascribed to the aromatic compounds in essential oils and other plant extracts.
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; After receiving a facial at an all-natural salon, a person experienced severe skin irritation, which highlighted the potential dangers of using "clean" beauty products marketed as being made from natural ingredients.
This incident underscores the misconception that natural compounds are always safe, revealing a growing awareness within the beauty industry about the risks associated with essential oils, which can lead to allergic reactions and skin damage;[18] there has been at least one case of death.
In case studies, certain oils have been shown to have a variety of deterring effects on pests, specifically insects and select arthropods.
[19] These effects may include repelling, inhibiting digestion, stunting growth,[20] decreasing rate of reproduction, or death of pests that consume the oil.
[21] Essential oils that have been investigated include rose, lemon grass, lavender, thyme, peppermint, basil, cedarwood, and eucalyptus.
[22] 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,[23] and marketed insect repellents, such as bug spray.
Since this stage is relatively short-lived, creams and polymer mixtures are used in order to elongate the vapor period of effective repellency.
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.
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.
[28] 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.
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.
Chemistry syringes are ideal, as they resist essential oils, are long enough to enter deep vessels, and have fine graduations, facilitating quality control.
Some essential oils qualify as GRAS flavoring agents for use in foods, beverages, and confectioneries according to strict good manufacturing practice and flavorist standards.
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,[46] and essential oils can cause irritation and nausea when ingested.
[48] The rest of the standards with regards to this topic can be found in the section of ICS 71.100.60 [49] 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.
The Persian physician Ibn Sina, known as Avicenna in Europe, was first to derive the fragrance of flowers from distillation,[52] 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.
