Properties and characteristics of essential oils
Characteristics of an essential oil
- The chemotype of an essential oil is a precise reference that indicates the majority or distinctive biochemical component present in the essential oil. It is the element that distinguishes an essential oil extracted from the same botanical variety but with a different biochemical composition. This vital classification enables essential oils to be selected for more precise, safer and more effective use. For example, under the same botanical name, we know two major thyme families, which are themselves subdivided by the definition of their respective chemotypes.
- Colour. An essential oil ages and oxidises. It should be stored away from light and air.
- Refractive index.
- Monoterpenes = immune system stimulantsBiochemical family of Ketones
- Monoterpenols = anti-infectious, bactericidal, viricidal and fungicidal compounds
- Sesquiterpenes = Slightly hypotensive, calming and anti-inflammatory
- Sesquiterpenols = Good general tonics and stimulants,
- Phenols = Strong anti-infectives and immuno-stimulants
- Diterpenols = Hormone regulators
- Aldehydes = Good anti-inflammatories
- Acids = Are hypothermizers and hypotensives
- Ketones = In low doses, they are calming, sedative and hypothermic. In large or repeated doses, they are neurotoxic, narcotic and epileptic, or even abortifacient.
- Esters = Anti-spasmodic and neurotonic properties, excellent nerve balancers
- Oxides = Bronchopulmonary decongestants: mucolytic and expectorant.
- Coumarins = Neuro-sedatives, anticoagulants.
- Lactones = act by hypothermising. They have a more powerful mucolytic action than ketones.
- Diones = Antispasmodic and anticoagulant, less toxic than ketones.
Relationship between the structure of essential oils and their activities
The study of structure/activity relationships consists of analysing the nature and importance of the relationships existing between the chemical structure of an essential oil and its physiological activity.
Unlike a medicine, which is made up of one or more isolated molecules with a very specific function, an essential oil is an assembly of constituents belonging to different chemical families, each with its own specific characteristics.
This is why essential oils have more varied activities.
However, essential oils can be grouped into 3 main families :
1 - Essential oils containing a large majority of an aromatic component : these essential oils will have a very specific property.
Example : Wintergreen essential oil (Gaulteria fragrantissima), 99% methyl salicylate, giving it its antispasmodic and anti-inflammatory properties.
2 - Essential oils composed of two main aromatic components.
Example : essential oil of Eucalyptus globulus, composed of 1.8 cineol (> 58%) and alpha pinene (209.6).
3 - Essential oils are made up of three main aromatic components, which have more varied and nuanced properties.
These aromatic molecules can be classified along 2 axes, according to their polarity and their positive or negative qualities, as shown in the diagram below.
Thus, an essential oil will have a more "calming and relaxing" profile or, on the contrary, a more "tonic and stimulating" profile.
Example 1 : Eucalyptus globulus essential oil
Major components : 1,8 cineol : terpene oxides - alpha pinene: monoterpenes
This essential oil has a strong tonic and stimulating effect. Eucalyptus globulus has :
- antiseptic, antimicrobial and antibacterial.
Example 2 : Essential oil of Lavandula angustifolla
Major components : linalyl acetate: ester family - linalool: alcohol family
This essential oil has a calming and relaxing effect. Fine lavender has :
- Negative (predominant),
- powerful antispasmodic,
- calming, sedative, muscle relaxant,
- variable anti-infectious.
Properties of essential oils
The properties of essential oils differ depending on whether the essence is extracted from the flower, leaf, root or seed. Generally speaking, essences extracted from roots are recognised for their action on the nervous system, those extracted from seeds and flowers for their impact on the entire digestive system and those extracted from leaves for their beneficial effect on breathing.
Each essential oil can have multiple properties. The chemotype already gives a good indication of these properties. The use of essential oils reduces viral and microbial attacks, reduces cell oxidation and increases the body's vitality. They provide our bodies with the most precious natural concentrates for restoring or maintaining the balance essential to our health.
- Deodorising, perfuming, antiseptic, protective...
- Diffused into the air or diluted in cleaning products, essential oils disinfect, deodorise and pleasantly and naturally perfume the air you breathe.
- They rid the air of pathogenic germs, and this regular practice prevents microbial illnesses by boosting the immune system.
- Citrus fruits are remarkable antiseptics.
- Geranium repels mosquitoes.
- The aromatic molecules with the highest antibacterial coefficient are the phenols: carvacrol, thymol, eugenol. A molecule that does not belong to this group, but is similar in the presence of a benzene ring, is cinnamic aldehyde (cinnamon).
- Used properly, these four molecules can control most common infections. Just behind the phenols are the monoterpenols (10-carbon alcohols): geraniol, linalool, thujanol, myrcenol, terpineol and menthol. Less powerful but also useful as an antibacterial agent is the group of aldehydes: neral, geranial, citronellal and cuminal. The ketones are useful in the treatment of infectious conditions: verbenone, thujone, cryptone, menthone, D. carvone, borneone, fenchone, but their neurotoxic and abortifacient properties make them difficult to use.
- To a lesser extent, ethers (estragole and anethole), oxides, phthalides and terpenes are used as antibacterial agents. Terpenes are mainly used for diffusion as an atmospheric antiseptic.
- In the fight against viruses, as with antibacterial agents, the hydroxyl group (phenol and monoterpenol) comes first, although phenols are more powerful and should be used with caution. For long-term use, monoterpenolic oils are preferable to phenolic oils, which are much more "aggressive". Essential oils stop viral progression.
- A blend of certain oils applied as a rub has a remarkable 'immunostimulant' action on deep respiratory infections, combined with eucalyptus radiata, for example, when diffused into the air.
- Pain relief
- The sharp pain of a migraine is anaesthetised by topical application of Peppermint.
- Tooth pain is eliminated by applying Clove to the gums.
- Cypress calms muscle cramps and rheumatism.
- Niaouli calms pain by numbing the nerves.
- Inhalation of niaouli will have a powerful expectorant effect on the respiratory tract.
- Eucalyptus applied to the skin is a powerful immunostimulant and mucolytic (expectorant). EOs rich in 1.8 cineols (oxide) have long been used and are very active (Eucalyptus globulus, Ravintsara, Rosemary), as they stimulate the bronchial glands and mobilise the cilia of the bronchial mucosa.
- Cypress stimulates the circulatory system, warming hands and feet.
- Lemongrass promotes blood circulation and the elimination of lactic acid. It will relieve muscular pains and aching feet.
- Essential oils have a strong anti-fungal effect on the air and skin. Fungal infections are extremely topical, as over-prescribed antibiotics encourage their spread. Here, we'll be using the same groups as those mentioned for combating bacteria. Sesquiterpene alcohols and sesquiterpene lactones are added.
- Antifungal essential oils include clove, lavender, rose geranium, palmarosa and rosemary cineole.
- Peppermint is the essential oil for digestive problems. It is effective for soothing colic, constipation, heartburn, indigestion and flatulence.
Essential oil synergies
When you mix essential oils, you are creating a synergy between them. Experience has shown that the therapeutic power of several oils is greater than that of a single one (there's strength in numbers!). Combining 2 or 3 oils with similar properties will create a synergistic blend that is both more powerful and different. Discover all our synergies for diffusion.
Quality guarantees of essential oils
Essential oils deliver exceptional results in all their areas of application. Their virtues are determined by their quality, which is the sum of several factors :
- The quality of the plants :
Wild plants, picked free from pollution or from certified organic cultivation", free from impurities and rich in energy. The final concentration of the product implies a search for maximum purity, with no trace of pesticides, weedkillers, radioactivity or heavy metals.
- Botanical recognition (Latin name) :
By giving their Latin name, which specifies the botanical species and avoids confusion. ("Eucalyptus", there are several hundred varieties)
- The part of the plant from which the oil is extracted (root, leaf, flower, seed) :
Highlighting the harmony, pleasure and remarkable complementarity between the aromatic plant world and the human world, Rudolf Steiner's Anthroposophists summarise the action of plants as follows :
- the roots act on the nervous system
- seeds and flowers on the digestive system as a whole,
- the leaves affect respiration and the heart.
Be careful when using essential oils !
As true concentrates of nature's invigorating, soothing and fortifying forces, they have very powerful therapeutic qualities and should therefore be used with moderation and caution.
- Essential oils should not be applied to mucous membranes or the eyes.
- Most essential oils should not be applied pure to the skin, but diluted in a vegetable oil such as sweet almond (unless otherwise indicated, do not exceed a concentration of 5%, i.e. 100 drops per 10cl).
- Some essential oils may irritate sensitive skin or cause an allergic reaction. If in doubt, test it by applying a patch (1 drop of oil in 1 spoonful of vegetable oil, apply to the fold of the arm, leave on for 24 hours, if a reaction occurs, discontinue use of this oil).
- Some oils are photosensitising (orange, bergamot, lemon and mandarin). Do not expose yourself to the sun after application.
- As a general rule, we advise against the use of essential oils by pregnant women, epileptics, people with heart problems or serious illnesses.
- For the use of oils for therapeutic purposes, we advise you to consult an aromatherapist.
- Never diffuse in the home certain pure essential oils that are too strong, such as Mint.
- Except in cooking, where the dosage on fats in sauces, creams and desserts is minute, the ingestion of essential oils is exclusively a medical matter.
Essential oils and children
- Essential oils should be kept out of the reach of children under the age of 3. Some manufacturers even indicate 7 years.
- In a baby's room, do not diffuse for more than 10 minutes, and only when the baby is not present.
- You can use them as a vapour or in the bath. Not all oils can be used in the bath, so reduce the quantities :
- From 3 months to 12 months: lavender, grapefruit (2 drops)
- 1 to 5 years: lavender, grapefruit, lemon, geranium, palmarosa (3 to 5 drops)
- 5 years to puberty: all oils considered safe for adults (5 to 8 drops)
Below is a list of essential oils which, for various reasons, are prohibited from being sold outside pharmacies :
1 - Absinthe Large (artemisia absinthium l) : This essential oil contains thujone (a highly convulsive monoterpene ketone). It can cause hallucinations.
2 - Absinthe Petite (artemisia pontica l) : This essential oil contains thujone (highly convulsive monoterpene ketone). It can cause hallucinations.
3 - Common mugwort (artemisia vulgaris l). : This essential oil contains thujone (highly convulsive monoterpene ketone). It can cause hallucinations.
4 - Artemisia arborescens (artemisia arborescens) : This essential oil contains thujone (highly convulsive monoterpene ketone). It can cause hallucinations.
5 - White mugwort (artemisia herba alba) : This essential oil contains thujone (highly convulsive monoterpene ketone). It can cause hallucinations.
6 - Worm-eating, goosefoot, false ragweed, Mexican tea, anserine or epazote (chenopodium ambrosioides l. and chenopodium anthelminticum l). : contains ascaridol, a toxic peroxide (powerful vermicide) which is particularly unstable (exploding under certain conditions).
7 - Sabine juniper or sabine (juniperus sabina l) : contains thujones (highly convulsive monoterpene ketones that can cause hallucinations), sabinol (terpene alcohol that attacks the nervous system and causes convulsions) and pyrogallol, which can poison (and rapidly kill) animals by blocking their digestive system
8 - Hyssop (hyssopus officinalis l) : contains pinocamphone (a neurotoxic and abortifacient ketone)
9 - Junciform mustard, brown mustard or Chinese mustard (brassica juncea [L.]Czernj. and cosson) : contains allylisothiocyanate, which is extremely toxic, particularly neurologically.
10 - Ruta (ruta graveolens l) : contains methyl heptyl ketone (highly neurotoxic and abortifacient).
11 - Sassafras (sassafras albidum) [nut] Nees) : contains safrol (a toxic component of ecstasy), a carcinogen.
12 - Sage (salvia officinalis l). : Its essential oil contains thujone (a highly convulsive monoterpene ketone). It can cause hallucinations.
13 - Tansy (tanacetum vulgare l). : Its essential oil contains thujone (highly convulsive monoterpene ketone). It can cause hallucinations.
14 - Eastern white cedar (thuya occidentalis) : This essential oil contains thujone (highly convulsive monoterpene ketone). It can cause hallucinations.
15 - Korean Cedar (thuya koraenensis nakai) : Also known as "Cedar leaf". Its essential oil contains thujone (a highly convulsive monoterpene ketone). It can cause hallucinations.
16 - Thuya (thuya plicata donn ex d. don). : Its essential oil contains thujone (a highly convulsive monoterpene ketone). It can cause hallucinations.
The list can be consulted by clicking on the following link : article D4211-13 of the Public Health Code dating from august 2007.
There is another restriction on the following essential oils :
- Star anise (Illicum verum)
- Green anise (Pimpinella anisum)
- Badian (Illicium verum)
- Fennel (Foeniculum vulgare)
The reason is given in the General Tax Code (article 514 bis Amended by Rapport - art. 1 (V) JORF 22 June 2000), an extract of which reads :
“As stated in article L. 3322-5 of the Public Health Code, it is forbidden for producers or manufacturers of essences that may be used in the manufacture of alcoholic beverages, such as essences of aniseed, star anise, fennel and hyssop, as well as producers or manufacturers of anethol, to sell or offer, free of charge, to any persons other than beverage manufacturers acting as warehousekeepers vis-à-vis the indirect taxation authorities, pharmacists, perfumers, food or industrial product manufacturers and direct export traders.
All these categories are prohibited from reselling these products in kind on the domestic market, with the exception of pharmacists, who may only dispense them on medical prescription and must enter the relevant prescriptions in their prescription register.
Without prejudice to the prohibitions mentioned in 2 of article 1812 of the general tax code, the conditions under which the essences mentioned in the first paragraph of this article as well as essences of absinthe and assimilated products or products likely to replace them may, in any form whatsoever, be imported, manufactured, put into circulation, held or sold, are fixed by decree by the Council of Ministers."