Beware of essential oils
- Dangerous substances -
The REACH regulation
The REACH regulation, which has been in force since 1 June 2007, confirms the obligation for the producer of any chemical substance listed in the EINECS inventory to produce a safety data sheet (SDS), either when the substance is classified as dangerous or when, as a preparation, it contains more than 1% by weight of at least one substance presenting a danger to health or the environment.
Since the introduction of this regulation, many products that had no information on their labels are now obliged to display the regulatory information. This is true for many products, including essential oils.
Essential oils and regulations
Essential oils, which have been used since the time of the Egyptians, have always been used for a wide variety of purposes: therapeutics, food, perfumery, cosmetics, detergents, industry, etc.
However, the regulations do not provide for the existence of essential oils as such. Each type of use has its own specific regulations, which must be complied with depending on the intended use of the product.
Essential oils may therefore be classified as medical devices, food supplements, cosmetics, insecticides or chemical products in all other cases.
The information given to consumers will be different, since each case is governed by different legislation, even though the same product comes from the same can...
7 golden rules for safe use
1 - Scrupulously follow the dosages, precautions for use, duration of treatment and route of administration. These are active extracts and must be used with care. For this reason, always keep your essential oil in its original packaging, with its instructions, which you can refer to at any time.
2 - Never substitute one essential oil for another, even if their names are similar. For example, true lavender and spike lavender have different indications, as do thymol thyme and linalool thyme, ravensare and ravintsara, etc.
3 - Always wash your hands thoroughly after using an essential oil.
4 - Do not heat essential oils excessively (by placing a dish on a candle, for example). Use a cold nebuliser, a ceramic soft-heat diffuser or a mister.
5 - Observe the precautions for use. Many essential oils are prohibited during pregnancy (especially the 1st trimester) and while breast-feeding. For children, some are generally not recommended before the age of 7. Always seek the advice of your doctor if you have a history of kidney or liver problems, seizure disorders or cardiovascular pathologies, or if you are prone to epilepsy, asthma or, in general, if you are undergoing medical treatment or have a long-term illness.
6 - If you are undergoing medical treatment, beware of interactions with essential oils! Ask your doctor or pharmacist for advice.
7 - An allergy is always possible, particularly in fragile or sensitised individuals. It's best to carry out a skin test (put 1 or 2 drops of essential oil in the crook of your elbow, wait 48 hours, then do it again and wait 1 hour to check there's no reaction).
Essential oils as food supplements
Essential oils are sold under the name of "food supplements". This name allows manufacturers to avoid the regulations on "chemical products", but also to sell these products with a VAT rate of 5.5% instead of 20%.
According to European Directive 2002/46/EC, food supplements are "foodstuffs with a nutritional or physiological effect, marketed in the form of capsules, pastilles, tablets, ampoules, herbal teas or drinking solutions, the purpose of which is to supplement our normal diet". In France, decree no. 2006-352 of 20 March 2006 'regulates' the marketing of food supplements.
As current regulations do not require manufacturers to prove the efficacy and safety of their product, it is very easy to transform an essential oil considered a "dangerous substance" into a "food product".
The only constraint is the label, which will be different, since on it you will find the indication "food supplement", possibly with the information "not recommended to exceed the indicated daily dose" and "keep out of the reach of young children".
Article 3 of Chapter II of this decree stipulates: "The ingredients mentioned in Article 2 may only be used in the manufacture of food supplements if they lead to the manufacture of safe products, not harmful to the health of consumers, as established by generally accepted scientific data".
In practical terms, this means that not all essential oils can be marketed as food supplements. Only those that are 'consumable' will be authorised, which already represents a substantial list (> 40).
Take, for example, the SDS for Mountain Savory essential oil (EINECS/CAS: 90106-57-3) published by a manufacturer on 11/03/2011 in compliance with GHS standards. Section 15 lists the regulatory information that must appear on the label of all bottles on the market :
- H226 Flammable liquid and vapour
- H302 Harmful if swallowed
- H304 May be fatal if swallowed and enters respiratory tract
- H314 Causes severe skin burns and eye damage
- H318 Causes serious eye damage
- H317 May cause skin allergy
- P301+P310 IF SWALLOWED: call a POISON CENTER or doctor immediately
- P405 Keep locked up
So, is mountain savory essential oil a "dangerous substance"?
Yes, if you read the manufacturer's SDS. No, if you consider that it is authorised and marketed as a "food supplement" !
Essential oils for diffusion
If we take the case of essential oils intended for diffusion, as they cannot be classified as either aromas or cosmetics, they can only be classified as chemical products or dangerous substances.
While legislation exists to warn consumers of the dangers of using certain products, manufacturers are keen not to frighten consumers with a range of information likely to discourage them from using their product!
So many manufacturers, following the interpretation of the various articles on the labelling of dangerous substances (bottle < 125ml, bottle too small, quantity so limited, etc.), have decided for the time being to put off implementing the new regulations on their products. Nobody wants to be the first to put a "skull and crossbones" or a "dead fish" on their label. And that's understandable !
Essential oils can be N, C, Xi, T, Xn, ...
A product label must be identical to the Safety Data Sheet (SDS) supplied with the product.
When you start reading the SDS of the most common essential oils, it's true that it can be scary.
Most are considered harmful (Xn) and often dangerous or even toxic for the environment (N). But that's not all. When they are not indicated as "irritating to the skin", they are specified as "avoid contact with the skin". Thyme, for example, causes burns (corrosive symbol). For products that can be classified as cosmetics, we don't understand the logic.
Of the 285 essential oils listed in the EFFA table, only 4 have no danger symbol. This means that most commercially available essential oils should have a danger symbol on the label. As this is rarely the case, we'll take a look at what these symbols mean :
- N-Dangerous for the environment
For aquatic toxicity (fish, algae, daphnia), its classification will depend on the quantity of mg/litre of water for which it will be considered :
- R53 if > 100mg/l
- R52/53 if >10 mg/l and < 100mg/l = Harmful
- R51/53 if > 1mg/ and < 10mg/l = toxic
- R50/53 if > 1mg/l = very toxic
This is certainly true in theory, but in practice, given that essential oils are considered insoluble in water and that the field of application is not the same, the products are hardly comparable.
Given the high price of essential oils, it is unlikely that anyone, whether deliberately or by accident, would pour a bottle of essential oil into a river. On the other hand, it's very easy to pollute a river by weeding your lawn just before it rains.
An IFEN study (August 2006) showed that glyphosate and AMPA (a derivative of glyphosate) were the substances most frequently found in water in France, although glyphosate is classified as less toxic than orange oil.
Definition Corrosive (INRS) : Able, in contact with living tissue, to exert a destructive action on the latter There are more than 200 corrosive substances. There are mainly acids and bases such as caustic soda but also thymol, phenol contained in thyme oil. Although thyme essential oil is much less corrosive than sulfuric acid, it should be used with caution. Avoid, like some people, taking a bath by adding pure thyme essential oil, otherwise you run the risk of coming out like a crayfish.
Definition Irritant (INRS) : Not corrosive but may, by immediate, prolonged or repeated contact with the skin or mucous membranes, cause an inflammatory reaction. Virtually all essential oils are classified as irritants, but that doesn't mean that if you put a drop of lavender essential oil on your hand you're going to get redness. This means that there are rules for using essential oils and that they must be respected. The first of these rules is to avoid using them pure on the skin but only after dilution in a vegetable oil, which is also indicated in all aromatherapy books.
Definition Toxic (INRS) : Causing death by inhalation, ingestion or skin penetration in small quantities, or damaging health acutely or chronically.
The T logo must be present on a bottle when at least one "Toxic risk" phrase is present in the SDS. It may be toxic by inhalation, in contact with skin or if swallowed.
These are essential oils that are particularly dangerous to use, but there are less than fifteen that are actually classified as Toxic (death's head). there are for example Sassafras, mustard, nutmeg, .. These essential oils are not normally available over the counter or are prohibited in France like sassafras.
Definition Harmful (INRS) : May, by inhalation, ingestion or skin penetration, cause death or harm health acutely or chronically
The Xn logo must be present on a bottle when at least one phrase "Harmful risk" is present in the SDS. This may be Harmful by inhalation, in contact with skin, if swallowed or may cause lung damage if swallowed
If few essential oils are classified T, many essential oils are classified Xn.
If we follow the definition, this means that more than 60% of essential oils found in commerce can cause death when used. It is therefore important to clarify this point.
- Definition of LD50-LC50
This indicator measures the dose of substance causing the death of 50% of a given animal population (often mice or rats) under specific experimental conditions. We will consider approximately that 1gr of essential oil = 20 drops
In the data below we see that the range is wide since there is a ratio of 10 between the minimum and the maximum, in order to verify the danger, the calculations will be made on the minimums.
- Harmful by ingestion (R22) :
- 200mg/kg > LD50 < 2000mg/kg
- Either for a person of 50kg = 10grs which makes about 200 drops of essential oils to absorb before reaching the threshold of harmfulness. It is technically very difficult to ingest a bottle of sage or cedar essential oil.
- N-Dangerous for the environment
Harmful in contact with skin (R21) :
Starting with the same calculation as above, we arrive at 20 ml. Technically, it is possible to massage the whole body with 2 bottles of pure essential oil, but this is a matter of total ignorance of the products. Oils classified as R21 are rare. There are, for example, oregano or Chinese cinnamon. These two oils are indicated in all aromatherapy books as "never use pure on the skin but always diluted"
Harmful by inhalation R20 :
2mg/L of air > LC50 > 20mg/L of air
A small room is about 20m3, the threshold of harmfulness will be reached with 40grs of essential oils in the ambient air, with a powerful diffuser we vaporize in the air 2g/h or 20 hours of diffusion without airing before reaching the critical threshold. Essential oils classified as R20 are rare, for example horseradish and mustard, so Harmful by inhalation therefore seems unlikely unless done on purpose !
The Xn symbol that may appear on a bottle rarely comes from R20 or R21 or R22 but most often from R65 (Harmful: may cause lung damage if swallowed) which is present on most essential oil SDSs.
R65 is applicable to all substances containing aliphatic, alicyclic and aromatic hydrocarbons with a low kinematic viscosity (< 7 mm2/s at 40°C). Aromatic Hydrocarbons are composed of hydrogen and carbon atoms such as benzene (C6H6), toluene (C7H8), xylene (C8H10), naphthalene (C10H8), phenols or limonene (C10H16).
The main source of production of aromatic hydrocarbons is the refining of crude oil. But we also find aromatic compounds in fragrant plants such as pine, eucalyptus, thyme, mint,...
As essential oils are classified as "hazardous substances", the same calculation is applied to them as that applied to white spirit, turpentine and other petroleum solvents.
This calculation method involves all substances which have a viscosity up to 7 times that of water (viscosity of water at 20°C = 1 and at 40°c = 0.661 mm2/s) and which contain at least 10% of an aromatic organic compound. They must have the symbol Xn and the phrase R65 on the bottle. We therefore find most essential oils such as lavender, cypress, rosemary, pine, eucalyptus but also all those that contain limonene such as orange, lemon or tangerine.
We understand why manufacturers are in no hurry to put the Xn symbol next to the AB logo on a bottle of orange essential oil when it is often used in food to flavor a cake.
Safety Data Sheet of essential oils
You should know that the Safety Data Sheet (often called SDS on our site) is produced by the product manufacturer.
If for synthetic products it can be simple since the products are always identical, for products of natural origin it can be much more complex.
The molecular composition of essential oils can change from production to production, from batch to batch, but normally the composition respects minimums and maximums of percentages of components, in accordance with the standard.
Essential oils are classified based on the results of direct tests on their physical, chemical, toxicological and ecotoxicological properties. But many test results are not available or too old or inaccurate to be valid.
In this case, the classification is made on the basis of the application of the rules applicable to dangerous preparations, from the hazard properties of the elementary chemical compounds of gasoline and the percentage of presence in it.
While waiting for the tests on the essential oils, the manufacturer must rely on the tables published by the EFFA (European Flavor and Fragrance Association) :
- Table 1 Classification, hazard symbols, R and S phrases of pure essential oils
- Table 2 Classification of components used in the preparation of essential oils
The easiest way is to use table 1 and apply the information: example for Lavandin absolut (EC No: 294-470-6): Xi-R38-R43-R52/53 (EFFA)
Or, you can use table 2 and do the calculation for each component of your essential oil. Example for Lavandin absolut (N°CE: 294-470-6): R66 R52/53 (Interprofessional Committee for French Essential Oils)
We see that, for the same product (same EC number), the information is not identical. But it is true that it depends on the origin of Lavandin.
Are essential oils dangerous ?
Essential oils have, in some cases, caused adverse reactions: the convulsive effect of camphor and eucalyptus essential oils in young children has been known for a long time. Let's analyze the 3 possible cases of toxicity in humans :
- Ingestion toxicity
In the United States, in 2006, the monitoring system (AAPCP) identified 7,377 cases of exposure by ingestion to essential oils. 74% mainly concern children under 6 years old and 1.2% of cases followed normal use.
These results must be handled with caution since the quantity ingested is absent for a majority of exposures and errors in the classification of substances and errors in diagnosis cannot be ruled out either.
It should be noted that no death has been reported following the ingestion of these different oils and that, in general, no death has been reported in the literature.
Almost all of the toxicological data are obtained after experimental tests on laboratory animals and therefore lack precision. Moreover, they are obtained by testing the active compounds alone and not the complete oil.
These data are therefore difficult to use to assess the risks of essential oils that are mixtures of several compounds.
Human toxicity data were most often obtained as a result of accidental ingestion (most often at very high doses and mainly on children).
Scientific studies show that essential oils may have some toxicity, but they appear to be toxic by ingestion only if it is made in large quantities and outside the conventional framework of use.
- Contact toxicity
Few toxicological data are available on the toxicity of essential oils by contact but some studies exist on the essential oil of tea tree and lavender. Patient sensitivity is tested using patches with a variable concentration of essential oil (from 1 to 100%).
- Irritation :
These results do not make it possible to conclude on a possible link between the concentration of Tea tree and the increase in the reactions of irritations (in view of the great dispersion of the results and the absence of medical history of the patients).
- Contact allergies :
The results seem to indicate a possible link between the increase in the concentration of Tea tree and that of the number of allergies. The percentages of allergic reaction, although relatively low, indicate that certain oils have an allergenic power and may therefore be contraindicated.
- Irritation :
- Inhalation toxicity
Although the toxicity of the main indoor air pollutants is beginning to be better known and to be the subject of measures to manage the risk they entail, few studies have to date been launched on the formation of compounds volatiles likely to be inhaled following the evaporation of essential oils.
The specific effects of essential oils by inhalation remain largely unknown to this day. However, in general, essential oils are suspected to be at least sensitizing agents.
Source of this paragraph : Possible risks and benefits of essential oils (March 2008-EHESP school)