IN ESSENCE…
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- A ‘pure’ essential oil can be defined as one that has been derived from its genuine botanical source and does not contain any fillers, additives, or other impurities.
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- Essential oils have sometimes been adulterated by unscrupulous businesses; this can involve adding vegetable oils, synthetic extenders, or even using false labeling claims in order to maximize on profits.
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- Adulteration is difficult to spot at home and can sometimes even trick the most experienced nose; the only way of reliably gauging the purity of an essential oil is via professional testing using techniques such as GC-MS.
- Trust is a critical factor when it comes to your essential oil supplier. The presence of a purity statement, transparency of testing, and an enduringly positive reputation, amongst other factors, can provide you with a peace of mind with regards to the purity and safety of their essential oil products.
INTRODUCTION
The purity of an essential oil is undeniably important. Whether you are an aromatherapy practitioner, owner of a cosmetic business, or simply enjoy essential oils at home, it is critical to use high quality oils that are pure, unadulterated, and safe to use.
But what exactly does it mean for an essential oil to be ‘pure’? And how can we reliably tease apart a ‘pure’ essential oil from an ‘impure’ one? In this article, we attempt to clarify these common concerns and also clear the air of some of the most widely-held misconceptions regarding the purity of essential oils.
WHAT IS A ‘PURE’ ESSENTIAL OIL?
Essential oils are concentrated botanical extracts that are typically derived via the steam distillation or expression of plant parts. The marketing campaigns of these potent oils are often adorned by exciting terms such as ‘100% pure’, ‘100% authentic’, ‘100% natural’, ‘pure and complete’, ‘clinical grade’, ‘therapeutic grade’, and other similar labels. Advertising claims aside, it can be difficult for consumers to get a true grasp on what essential oil purity actually is and how it fits within other indicators of quality.
Simply put, purity is closely tied to the composition of an essential oil. It can be defined as the state of being fully and completely composed of the plant source or plant species that is printed in Latin on the label of the bottle. In other words, the essential oil has not been adulterated or contaminated by potentially toxic or synthetic substances.
Other views on essential oil purity also exist. Some aromatherapists, for example, believe that purity should be characterized more by the therapeutic impact than the exact composition of the oil; this suggests that purity is something that is more difficult to describe or quantify. Some stress the value of ‘authenticity’, which stretches the definition beyond adulteration to consider the purity of the botanical source even before it is distilled or pressed.
| MYTH: There is a universally accepted definition of essential oil purity.
FACT: There is no one way to define or recognize the purity of an essential oil. However, it is commonly accepted that a pure essential oil is one that has been extracted from its genuine botanical source and does not contain any fillers, additives, or other impurities. |
According to the more mainstream definition, essential oil purity is somewhat different from essential oil quality. Two batches of the same essential oil can be 100% pure yet still vary in quality; this is because there are many factors that can give rise to natural, honest variations in the composition of the essential oil and its principal components. This includes the climate, geography, harvest methods, distilling methods followed by the producer, and the time spent under storage conditions. If the botanical in question has thrived with plenty of rainfall, for example, its resulting essential oil is likely to be of higher quality than if the region was going through a drought. Similarly, the timing of the harvest is critical; if the fruits or leaves of a botanical are harvested prematurely, then they might not contain the ideal amounts of therapeutic constituents even before it is distilled.
| MYTH: A pure essential oil is automatically a high-quality one.
FACT: Purity is an indicator of, but is not necessarily synonymous with, quality. |
The consequences of using impure or adulterated essential oils can be immense. On one level, these oils may not offer the same level of therapeutic or cosmetic benefits as an unadulterated oil, and can further compromise the integrity and performance of products if they are added to formulations. On another level, they may be toxic or otherwise unsafe to use, causing adverse reactions or sensitivities.
How Do Natural Blend Oils Compare With 100% Pure Essential Oils?
Natural Blends consist of a blend of essential oils and natural isolates such as Linalool, Eugenol, and α-Pinene, all derived from natural botanical sources. As they are not extracted from a single source, they are not classed as 100% pure essential oils but act as a more economical substitute that exudes an identical fragrance. They are used to infuse rich scents into a wide range of natural products such as soaps, candles, shampoos, perfumes, and lotions.
Due to the absence of synthetics, Natural Blends can be used in cosmetics without having to resort to artificial fragrances that may contain potentially harmful substances. They are also preferred as essential oil alternatives for endangered or protected plant species such as Rosewood. However, it is important to note that Natural Blends do not offer the same therapeutic value of pure essential oils and so are not suited for aromatherapy.
Are Organic Essential Oils ‘Purer’ Than Non-Organic Oils?
Many believe that organic essential oils have a higher level of purity than conventional oils. It is true that an organically-produced essential oil (which has been certified by an appropriate authority such as the QAI) is likely to be superior in some important aspects, such as its color, aroma, safety, sustainability, and its therapeutic value. In particular, they have been verified to comply with agricultural and manufacturing practices that actively seek to avoid GMOs and reduce the amount of synthetic pesticides, chemical contaminants, and other toxic compounds. As a result, organic essential oils may be more ‘pure’ with respect to these substances.
However, this does not mean that non-organic oils are somehow lacking in purity. There are many reputed suppliers that are dedicated to the purity of both their organic and non-organic oils, source ethically from premium-quality farms, and strive to guarantee the integrity of their essential oils. Whether an oil is certified organic or not, an essential oil batch can be tested to ensure the quality is at the highest possible standard in terms of purity and does not contain adulterants, bacteria, mold, and other dangerous or hazardous substances.
| MYTH: Conventional essential oils are less ‘pure’ than organic oils.
FACT: The purity of an essential oil can be tested and assured whether or not it is certified organic. That said, an appropriate organic certification can provide some added confidence that extra care has been taken to avoid contamination with substances that are not routinely tested for, such as pesticides. |
WHAT IS ESSENTIAL OIL ADULTERATION?
No matter the industry, all essential oil stakeholders are driven by a need to search for the purest of oils at the fairest of prices. Unfortunately, some essential oil suppliers and companies have come to rely on unscrupulous practices to satisfy this need in the market, selling adulterated or contaminated products disguised as pure and authentic oils.
Adulteration is the practice of modifying the composition of essential oils using dishonest techniques, typically so that they may be sold at cheaper prices. There are many ways an oil can be adulterated:
Diluting with carrier oils
A relatively simple method of adulteration, it involves adding vegetable or mineral oils to ‘bulk up’ the volume of an essential oil. This can sometimes lighten the fragrance of the essential oil, although there have been cases of this being done in such a subtle way that even trained evaluators have not been able to detect it by smelling the aroma. It is often claimed that this kind of adulteration can be tested using a blotting paper; while this is true, it has been observed that over the last few years these simple diluting techniques are also no longer being practiced.
Diluting with other essential oils
To boost profits, a more inexpensive essential oil may be mixed in, while ensuring the fragrance remains more or less consistent. Pricy Neroli oil, for example, can be adulterated with the far cheaper Sweet Orange essential oil, and likewise, expensive Melissa oil is sometimes compromised by diluting with Citronella oil which exudes similar lemon undertones.
Adding synthetic constituents
A shortcut to passing some quality controls or enhancing the aroma, compatible synthetic compounds can be easily added to an essential oil. For example, Litsea Cubeba oil can be adulterated by incorporating the synthetic version of its main constituent, Citral. Similarly, Peppermint oil and Geranium oil have also been known to be adulterated synthetic versions of their active constituents as well: Menthol and Citronellol/Geraniol, respectively.
Adding natural constituents
Natural constituents may also be isolated from a botanical source and mixed in to improve the aesthetics of a nature essential oil. For example, the constituent 1,8-Cineole (also known as Eucalyptol) can be extracted from Eucalyptus and added to Rosemary oil to strengthen its herbal aroma and stimulating properties. The key distinguishing factor in the case of adulteration (as opposed to the use of natural constituents in Natural Blends, for example) is that these alterations are not declared and are sold at the same price as a pure essential oil.
Mixing non-organic oils with organic essential oils
There have been cases where certain companies have been suspected of adding non-organic oils to certified organic oils in another attempt to boost profits.
Fraudulently labelling an essential oil or oil blend
In a more severe type of adulteration, some suppliers or distillers have disguised and labeled cheaper essential oils (or essential oil blends) as more expensive ones. The high production cost of Melissa oil, for example, has tempted dishonest business owners to blend Citronella oil, Lemongrass oil, Litsea Cubeba oil, and other components together to create fake versions of Melissa. Sometimes an expensive variety of oil, such as for Sandalwood and Sweet Orange, have been replaced by a less expensive or inferior variety.
WHAT STANDARDS EXIST FOR ESSENTIAL OIL PURITY?
Some international bodies have created guidelines in an attempt to standardize the quality and purity of essential oils. For example, the International Organization for Standardization (ISO), an international NGO that defines and sets forth quality standards for many industries, have outlined quality parameters for essential oils; these include the essential oil’s aroma, color, physicochemical characteristics (such as density and refractive index), as well the minimum and maximum percentages that should be achieved by instrumental tests such as Gas Chromatography. This information can be accessed by companies or distributors who desire to analyze and certify their essential oils as complying with ISO’s norms.
The ISO is currently the primary international authority known for its quality parameters for specific essential oils. However, it is important to understand that their main motive is to help assure the safety and consistency of essential oils and not necessarily their overall quality. For this reason, ISO does not offer guidance on how essential oils could be placed into different tiers of purity, for example, or how one could gauge the overall appeal or therapeutic impact of the oil. Nevertheless, they serve an excellent starting point of reference for companies to understand and control the quality of their essential oil products; an ISO-certified essential oil should provide additional assurance that it meets international safety standards.
On a national scale, the following organizations also offer suggestions and guidelines regarding essential oil quality:
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- Association Française de Normalisation (AFNOR) – contributes to ISO specifications.
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- British Standards Institution (BSI) – also contributes to ISO specifications.
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- The British Pharmacopoeia (BP) – produces quality information and references for essential oils prominent within the pharmaceutical sector.
- The United States Pharmacopeia (USP) – also produces quality information and references for essential oils prominent within the pharmaceutical sector.
HOW CAN I KNOW IF MY ESSENTIAL OILS ARE PURE?
If the purity of an essential oil can be defined by its composition, then it follows that purity can be assessed by analyzing what each specific oil is made up of. Essential oil purity tests do exactly this; they attempt to gather data from different angles to allow a conclusion to be made regarding whether the essential oil has been adulterated or possibly contaminated.
There are many ‘home tests’ outlined on the web that allow consumers to evaluate their own essential oils. However, these are rarely reliable and so should not be trusted. Apart from finding a credible supplier whose purity tests you can trust, perhaps the most reliable way to assess your essential oils would be to consult an independent tester and have them professionally tested.
| MYTH: The blot test – and other ‘home tests’ – will let me know if my essential oils are pure or not.
FACT: The blot test is an out-of-date technique as adulteration by diluting in vegetable oils is now seldom practiced. Other home tests are rarely reliable. |
There are three main analytical branches that attempt to hone in on purity: 1) organoleptic, 2) physical, and 3) chemical. In all three cases, essential oil purity must be deduced by a qualified and experienced analyst. This is because experience in required to interpret arising results; deviations can sometimes be attributed to storage conditions, the simple aging of the oil, an error in the analysis, or even to natural peculiarities of the botanical source.
Organoleptic Evaluations of Essential Oils
An organoleptic test involves using the senses to closely examine the quality of an essential oil. The color, texture or consistency, and finally the aroma can be evaluated to be able to pinpoint if there are specific issues within the product.
In order for organoleptic tests to be accurate, it must be conducted by a trained professional who holds in-depth experience in working with essential oils that are of many different varieties and qualities. It also demands a high level of diligence and concentration because the tests must be repeated with a large number of samples. Sometimes, however, due to the inherent subjective nature of smelling and/or sensing, organoleptic tests can suffer from low reliability.
| MYTH: If I don’t like the scent of an essential oil, it must have purity and/or quality issues.
FACT: This is not an accurate way of determining the purity of an essential oil. In fact, many years of experience is required to develop the sensitivity needed to perform an organoleptic test. |
Physical Evaluations of Essential Oils
This involves assessing the physical or physicochemical properties of an essential oil, such as its density, optical rotation, refractive index, solubility with ethanol, and freezing point. For example, a pure essential oil is associated with a particular density relative to water. This value can therefore be measured in order to check whether the sample oil is pure or has been adulterated.
Similarly, essential oils display optical activity, which involves their capacity to rotate plane-polarized light; the degree of this rotation can be measured, along with its direction, using a piece of equipment called the polarimeter. The result can then be compared to a reference value such as those published by the ISO. In this way, the identity of an essential oil can be honed in on, and consistent outliers can alert to possible impurities or adulteration.
Chemical and Instrumental Evaluations of Essential Oils
The most accurate (and also most expensive) analytical branch consists of chemically evaluating the composition of an essential oil. Included in this is the sophisticated GC-MS (Gas Chromatography–Mass Spectrometry) Test that has now become synonymous with essential oil purity testing.
GC-MS unites the techniques of Gas Chromatography (GC) and Mass Spectrometry (MS) to enable the identification of the different chemical components comprising an essential oil. GC splits the oil into its individual constituent parts depending on its molecular structure, while MS analytically identifies each constituent to produce a results ‘spectrum’. In this way, an evaluator can conclude which components, along with their percentages, were present in the sample – much like a chemical ‘fingerprint’. By comparing the results with a spectrum that represents a known, pure sample, the purity of essential oil in question can be determined.
Reputed suppliers will carry out GC-MS testing for every batch of essential oil before trading. It is important to note that natural variations are possible from batch to batch; however, GC-MS results can help uncover whether the values for each chemical component fall within a standard range.
| MYTH: GC-MS testing erases the need for other kinds of purity testing.
FACT: GC-MS, while a sophisticated technique of analysis, is best accompanied by other tests, including additional physical and physicochemical testing, in order to provide a full picture regarding purity. |
KEY THINGS TO LOOK FOR IN YOUR ESSENTIAL OIL SUPPLIER
Ultimately, sourcing pure and high-quality essential oils lies on the ethics and accountability of your supplier. The following points are important to consider before purchasing from a specific supplier or company:
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- Solid reputation – does the company have a well-established reputation for supplying high-quality oils at fair prices?
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- Transparency – are up-to-date GC-MS reports, Safety Data Sheets, and Certificates of Analyses easily accessible for each essential oil product?
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- Statement of Purity – does the company have a published statement regarding their commitment towards purity?
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- Certifications – has the company gone to lengths to achieve certifications that are reputable and internationally recognized (such as by the ISO and USDA)?
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- Responsive to Inquiries – does the company welcome questions and inquiries from customers regarding quality and sourcing information about their products?
- Community Participation – has the company demonstrated an active and engaged participation with the community, for example through ongoing professional memberships and/or an educational blog?
A positive standing on the above factors can help build your confidence regarding the level of quality, purity, and safety of the essential oils you use, enjoy, and trust.
Read more about Essential Oil quality and composition here.
Uncover all the differences between Organic and Non-Organic Essential Oils here.
USING ESSENTIAL OILS SAFELY
It is important to enjoy the benefits of essential oils while using them safely and responsibly. This includes never using them undiluted, performing a skin patch test prior to use, being knowledgeable about the sun’s effects after use, and sourcing them from an ethical brand known for quality and purity.
External use only
As with all other New Directions Aromatics products, essential oils are for external use only. Essential oils must never be used near the eyes, inner nose, and ears, or on any other particularly sensitive areas of skin. It is imperative to consult a medical practitioner before using these oils for therapeutic purposes.
Pregnancy and other health conditions
Pregnant and nursing women are especially advised not to use essential oils without the medical advice of a physician.
Those with the following health conditions are especially recommended to consult the advice of a physician: cancer, heart-related ailments, skin disorders or allergies, hormone-related ailments, or epilepsy.
Individuals that are taking prescription drugs, undergoing major surgery, or who are at a greater risk of experiencing strokes, heart attacks, or atherosclerosis are also advised to seek medical consultation prior to use.
Children and safety
These oils should always be stored in an area that is inaccessible to children, especially those under the age of seven.
How to conduct a skin patch test
Prior to using any essential oil, a skin test is recommended. This can be done by diluting 1 drop of the essential oil in 4 drops of a carrier oil and applying a dime-size amount of this blend to a small area of non-sensitive skin.
Essential oil side effects
Potential side effects of essential oils include redness, rash, hives, burning, bleeding disorders, decreased speed of healing, low blood pressure, dizziness, headache, nausea, diarrhea, convulsions, and rapid heartbeat. In the event of an allergic reaction, discontinue use of the products and see a doctor, pharmacist, or allergist immediately for a health assessment and appropriate remedial action. To prevent side effects, consult with a medical professional prior to use.