Aromatherapy - Explanation of Terms

Essential oils are aromatic substances. They are extensively used in cosmetic, pharmaceutical, and food industries as well as other fields. Aromatic substances activate the human smell and taste receptors and evoke the perception of odour or taste. This very complex sensation brought up by aromatic substances is called the AROMA.

Apart from perception of odour and taste the plant aromatic substances bring about an important biological activity (bioactivity) which then affects different organ levels according to the nature of the plant. Bioactivity however does not bring about only positive effects but can also have a negative influence. Essential oils, which contain any of these substances, are not used in aromatherapy or their use is limited. When bioactivity of essential oils acts on live organism we call this process an AROMATHERAPY.

In aromatherapy we work with aromatherapeutic materials based on bioactivity of essential oils. Another important components are VEGETABLE OILS. Their bioactivity is also important but in comparison with essential oils they work on a different biochemical level. Essential oils are volatile, unstable, colourless or coloured liquids of a different viscosity. They do not dilute with water but dilute well in vegetable oils, honey, alcohol, milk and cream. They contain hydrocarbons and oxygenous substances which mainly carry their aromatic and gustatory attributes. Vegetable oils however are fats made out of lipids.

Apart from essential oils and vegetable oils aromatherapeutic products may contain other components such as natural colours, lecithin, herbal extracts, bee wax, cocoa butter, vitamins etc. These components are more usually used in the area of professional manufacturing.

Biogenesis of Essential oils

Essential oils are products of the secondary metabolism of plants during which process the substances of the primary metabolism such as starch, fats and proteins are degenerated. Constituents of essential oils are made by two biogenetic processes. During the main process the terpenic substances are made and another process is needed to produce for example coumarins, furocoumarins and phenols.

Essential oils are stored in different parts of a plant - mainly in flowers and fruits but also in leaves, bark and roots. They are stored in glandular trichomes, glandular cells, secreting channels, intercellular spaces etc. and their function in the plant is still partly unclear. Generally it is thought that essential oils serve to attract pollinating insects and they also protect plants from pathogenic effects. The amount of essential oil in a plant varies throughout its vegetation (ontogenesis) as well as within the 24-hour period, which proves the active role of essential oils in a plant’s metabolism.

Extraction of Essential oils

Essential oils are extracted from the plant material generally by four technological methods.
1. Steam-water distillation (used for extraction of a majority of essential oils).
2. Extraction by organic solvents. Petrol or petrolether are mainly used for flower extraction. As a result of this process the so called "concrete" is extracted which also contains waxes and other substances. These are then removed by dissolving "concrete" in warm alcohol and freeze-drying. The result of this process is called an ABSOLUTE. High quality oils are produced by CO2 extraction under pressure.
3. Extraction of flowers by enfleurage into fat - either the cold way into odourless fat or by maceration in hot fat. Enfleurage is a very expensive process which is used only for precious oils such as Jasmin (Jasminum, Oleaceae) or Tuberose (Polyantes tuberosa, Agavaceae).
4. Pressing (mainly used for the extraction of essential oils from the rind of citrus fruits).

Quality of Essential oils

Apart from pure essential oils, synthetic "essential oils" are also manufactured. Their price is several times lower but their bioactivity is sporadic or none at all. Bioactivity can be guaranteed only by 100% pure natural essential oils. They are mainly extracted from monoculturaly cultivated plants, less then from wild crafted plants. When buying essential oils it is advisable to look for the highest quality available.

The distributors must be able to provide:
- A sales permission issued by the Office of the Main Health-Officer CR.
- A latin botanical name of the plant the essential oil is extracted from.
- The country of origin e.g. Rosemary Essential Oil, Rosmarinus officinalis, Spain or Tunis.
- The type of cultivation of plants used for essential oil extraction e.g. wild crafted, organically grown etc.

On the variety of the same plant (e.g. Peppermint, Spearmint) and its origin depends the quality, aroma and the proportional representation of the active chemical constituents in the essential oil.

Volatility of Essential oils

As it was already said, essential oils are volatile substances - diffusing freely in the air. According to their volatility we can divide essential oils into three categories:
1. High volatility - essential oil vaporizes within 24 hours (e.g. Eucalyptus, Peppermint)
2. Medium volatility - essential oil vaporizes within 48 hours (majority of essential oils)
3. Low volatility - essential oil vaporizes within 7 days (e.g. Jasmin, Rose, Neroli, Vetiver)

Volatility of essential oils is important for manufacturing aroma compositions for aromaterapeutic products or perfumes. Essential oils with low volatility are called aroma fixatives.

Use of Essential oils

Essential oils are mainly used in perfume, pharmaceutical and food industries. They are also extensively used for manufacturing professional and home cosmetics, in dermatology, massage and physiotherapy. They can be used to support healing or as parts of medicinal drugs, however their use is strictly regulated. Essential oils are highly concentrated materials and one drop contains aroma and bioactive components of approximately 1 kg of plant material. Therefore it is necessary to use essential oils in dilution. Higher concentration in cosmetic products may cause damage to the tissues and mucous membranes.

If essential oils are used exactly and professionally they form synergistic complements to other materials such as vegetable oils and vitamins.

Using essential oils in the fields mentioned above carry several advantages:
1. Purity of essential oils (if the top technology is used).
2. Exact classification of essential oils.
3. Application of the minimal amount of essential oil in products.

Use and Application of Essential oils

Inhalation

As volatile substances, essential oils vaporize if left freely in an open space. After inhalation the perception is sent through olfactory nerve to the olfactory centre of the brain. Out of olfactory centre the aromatic substance influences autonomous nervous system. It can, for example, lower or increase the blood pressure, impose the feeling of coldness or warmth, it can refresh, stimulate, relax, ease headaches and pains, etc.

Inhalation of essential oils can be used in psychotherapy to aid healing of all sorts of psychosomatic disorders. In the same way the pleasant smell can contribute to improving the environment at home or at the work place.

To inhale essential oils different inhalators, diffusers or fragrance burners are commonly used. Directions for use of inhalators and diffusers are set by manufacturers. With the fragrance burners we fill up the bowl to the top with water. Ideally the bowl should hold approx. 100 ml of water and the bottom of the bowl should be at least 7 cm above the bottom of the burner to prevent evaporation at a very fast rate. We put 4 - 8 drops of essential oil to the water. For fragrance burners only pure paraffin candles should be used. It is the heat source which warms up the water in the bowl and speeds up evaporation of essential oil. Fragrance burners are commonly made of pottery, porcelain, steel, glass or any combination of these materials.

It has been proved that inhalation always takes place when working with or using aromatherapeutic materials. A marked effect is achieved for example when using bath oils and sauna blends. We choose essential oil for inhalation according to its suitable aroma and desirable therapeutic action.

Essential oils are also being used in perfume compositions either as individual natural constituents or together with other synthetic components.

Application to the skin

Essential oils diluted in an appropriate carrier penetrate through all layers of the skin eventually reaching the blood capillaries. Vegetable oils are the optimum carriers as they easily penetrate into intercellular spaces.

Without taking into account the use of essential oils alone, the simplest aromatherapeutic product for external use is a massage oil. We can call these oils regenerative massage oils drawing the attention to the complex positive effect on our organism. These oils are mainly used for aromatherapeutic massage but are often utilized in other types of massage too. A local application is also an effective way of using massage oils in cases of painful muscles or joints, skin disorders, to support healing processes or just for common daily treatments.

Massage oils are very easy to prepare:

For carrier we usually use the following vegetable oils: sunflower, olive, sweet almond, sesame, grape seed and jojoba, either alone or in a blend of two or three.

Essential oils are blended in carrier vegetable oils at an amount of 1-3%. Bottles with essential oils should be equipped with a dropper so it is easy to remember that 30 drops equal approximately 1 ml. To get 100 ml of massage oil we add 30 drops for 1% concentration, 60 drops for 2% concentration and 90 drops for 3% concentration.

As an example: carrier oil made out of equal parts of jojoba and grape seed oils together with essential oils of either Lavender or Rose, Jasmine, Neroli or Sandalwood (or in any combination) make excellent regenerative face oil for daily use.

Internal use of essential oils

Internal use of essential oils is in a way similar to drinking herb teas and extracts. The active components are very quickly absorbed into blood stream having thus almost an instant effect.

We must bare in mind the potential toxicity of certain constituents of some essential oils (e.g. thujone in Sage) and adjust the dosage accordingly. Please be aware that many essential oils are NOT suitable for internal use at all. It is the least used and considerably risky method of application of essential oils.

A few notes when using essential oils

Study thoroughly actions and uses of essential oils. Choose carefully only good quality essential oils (you can follow some criteria described under Quality of Essential Oils).
- Cheap essential oils are usually not reliable.
- Essential oils of unknown origin or distributor with missing information about the production date or latin name are most probably of unreliable quality.
- Many commonly sold essential oils are labelled: for use in fragrance burners or pot-pouries (dried flower compositions). They are mainly synthetic or blended and not suitable for external or internal use. Synthetic essential oils smell similar to natural essential oils but do not carry any biological activity.
- Higher price should guarantee good quality however it is unnecessary to buy over-priced goods. Essential oil plants are grown in many countries all over the world and distributors often buy essential oils at the same wholesale company. If two distributors are selling essential oils from the same area and the same harvest let’s look for reasons justifying the higher price. If no acceptable answer is given we can easily buy the cheaper oils.
- Preserve the quality of essential oil during the use. Do not leave the bottle open for too long as essential oils vaporize easily. Do not expose bottles to extreme temperatures or temperature swings. Ideally essential oils should be kept in cold dark places in air tight bottles.
- Take care to dilute essential oils correctly. Higher concentration may cause irritations to skin or mucous membranes.
For example: add 10-20 drops of essential oil to bath or a sauna; use 25 drops into 50 ml of vegetable oil for massage; add 4-8 drops to the fragrance burner.
- To use essential oils to support medical treatment consult your GP or a specialist.
- Respect the gifts of nature. Natural materials including essential oils have been serving us ever since the ancient times. Their fragrance refines our senses and tunes us into natural and sublime belonging to the outside world. It reminds us that harmony lies just at a hand’s reach. Treat essential oils with caution.