Aromatherapy

Essential oils are the aromatic, volatile liquids that are extracted from the leaves, seeds, stem, bark, and resin or fruit rinds of plants. Often referred to as the" life force" of the plant and not one essential oil alike. To obtain the correct essential oil the plant must be harvested at the correct time of year, and the right part of the plant must be used. The method of extraction must also be pure in order to avoid any contamination and also to keep up with quality control standards so that the final product is assured. Chemicals are often used so that the oils can be extracted in much greater quantity and more quickly. Using chemicals proves to be cost effective but some solvents that are used to extract essential oils are toxic and also they may ruin the properties of the oils. Although there are many safe methods of extraction one method in particular may have cause for concern. Solvent extraction is used to extract the essential oils from the more delicate plants such as Jasminium grandiflorum whose aroma would most definitely be destroyed if it underwent the extraction process such as steam distillation. During solvent extraction a chemical such as hexane is used to saturate the plant matter and this process draws the essential oils out. Even though this process is widely used it is believed that a residue of the solvent is still present in the end product. A banned substance known as Benzene which was previously used in solvent extraction left a residue of up to 20% in the end product. Benzene was banned as it was said to contain carcinogenic properties.

Although essential oils are natural and generally safe for all to use it should be noted that there are many safety issues that are related in conjunction with administering these oils." It is undeniable that, along with the undoubted power of essential oils, there will be some unwanted effects" (Price % Price, 1999, p49).

Essential oils are known by the plant from which they have been harvested from. In aromatherapy the botanical name of the plant is always used, for example, the essential oil commonly known as Myrrh would be translated into its Latin name, Commiphora molmol from the Buseraceae family.

Like all organic compounds, essential oils are made up of hydrocarbon molecules and can further be classified as, Phenols, Alcohols, Esters, Terpenes, Ketones and Aldehydes, these are the main chemicals but there are also less common ones. These can be broken down further into chemotypes such as linalool, thujamol etc. The chemotype of an essential oil shows the major chemical constituents that are present in that oil. It is this chemotype that ascertains the essential oils which are extracted from the same botanical variety but will produce a very different chemical composition. This categorisation of essential oils allows for the right oils to be administered for the correct and effective use. Therefore, two chemotypes of the same oil will have contrasting properties and toxicities. One example of this is the essential oil Thymus vulgaris, when the chemotype is thymol the properties are excellent for bronchial disorders, but when the chemotype is linalool it is said to be a good cerebral stimulant.

With so many people using alternative medicine such as aromatherapy it is quite worrying that not many know the full potency of essential oils. When used in the correct way the adverse effects are minimal. The use of essential oils in aromatherapy has lead to many scientific studies relating to their safety, while the majority of them presenting very little risk there are a small amount that are deemed poisonous and toxic. Tisserand % Balacs (1995) states that "there have been a number of deaths from accidental ingestion of large quantities of essential oils such as Gaultheria yunnanensis (p. 15).

There are many reasons that essential oils may be deemed to be harmful, along with toxicity and poisonous oils some are phototoxic, this is where the essential oil components react with the skin while under ultraviolet rays, The phototoxic essential oil such as Citrus bergamia is widely used whether in aromatherapy massage, oil burners or bath oils, but Battaglia (1997) states that "the average furocoumarin content is quite high at 0.2 to 0.5 %. Citrus bergamia phototoxicity is classified as severe and should be used in dilutions of les than 1% to avoid phototoxicity (p.146).

With safety being extremely important tot both the consumer and the professional, and the fact that essential oils are found all over the world and therefore may be quite difficult to determine their quality. If the quality of the oil is in doubt it may well result in no therapeutic effect but worse still it may result in toxic reactions. With essential oils consisting of many different chemicals its contents may be affected by the way in which it is grown, the conditions of its harvest, extraction techniques, and also the way in which they are stored and handled. To make things more difficult as to how to determine their purity, some sellers of essential oils claim that their oils are pure when in fact they alter the oils by ways of diluting or cutting them with synthetic materials. With this in mind it may be very hard to make sure of the essential oil quality as it has been through so many hands before it eventually reaches the consumer.

There is no sound technique for guaranteeing essential oil purity but fortunately there are a few methods available as to how to analyze its purity. Gas chromatography and Mass spectroscopy or GC/MS is the most common way to analyze essential oil components. This form of testing requires an analytical component, this being the GC, and a detection component, this being the MS. The essential oil that is being examined is heated until it turns to a vapour, the vapour is then pushed along by an inert gas, while the vaporised essential oil is carried through its molecules then become separated, then It passes through into the MS, this is where the components become charged. The charged components are the amplified and detected. Each component that has been detected is shown as a peak in a chromatograph and so can compared in order to identify the substances. This method of analyzing essential oils can detect any trace of solvents that may have been used. Another way of testing essential oils is high performance liquid chromatography or HPLC, in this method of testing a liquid solvent carries the essential oil through a column which is filled with solid particles. The different components of the essential oils then slow down and are separated; this is known as the stationary stage, when the essential oils are in this stage each component is detected by a peak in the chromatograph. While these tests are certainly a great benefit for those that