The chemistry of an essential oil

Essential oils are natural aromatic compounds found in the seeds, bark, stems, roots & flowers of plants. They can be both beautifully & powerfully fragrant, eliciting profound emotional responses. Yet the use of essential oils goes well beyond their fragrant appeal. Used throughout history for their medicinal & therapeutic benefits, essential oils can be used as natural alternatives in holistic self-care practices. Their unique chemistry allows them to be used aromatically & applied topically to the skin, while other essential oils can be used as dietary aids to promote vitality & well being.

Essential oils are non water-based phytochemicals made up of volatile aromatic compounds. Although they are fat soluble, they do not include fatty lipids or acids found in vegetable & animal oils. Essential oils are very clean, almost crisp, to the touch & are immediately absorbed by the skin. Pure, unadulterated essential oils are translucent & range in color from crystal clear to deep blue.

Harvesting history

In addition to their intrinsic benefits to plants & being beautifully fragrant to people, essential oils have been used throughout history in many cultures for their medicinal & therapeutic benefits. Modern scientific study & trends toward more holistic approaches to wellness are driving a revival & new discovery of essential oil health applications.


Essential oils are used for a very wide range of emotional & physical wellness applications. They can be used a single oil at a time or in complex blends depending on user experience & desired benefit. Essential oils are usually administered by one of three methods: diffused aromatically, applied topically or taken internally as dietary supplements.


Our sense of smell influences many physiological pathways, including the stimulation of hormones & other metabolic processes. Aromatherapy is founded on the body’s predictable response to specific olfactory stimuli. Essential oils are widely used in aromatherapy applications. Certain essential oils, when diffused in the air, can be very stimulating, while others can be calming & soothing. Beyond emotional benefits, diffusing essential oils can purify air of unwanted odors & some airborne pathogens. Low or no-heat essential oil diffusers are recommended as they do not change the chemical structure of the oil being diffused. Essential oils can also be used as cleansing & purifying additives to laundry and surface cleaners throughout the home.

Due to their natural molecular composition, essential oils are easily absorbed by the skin & can be safely applied topically. Application of essential oils can have immediate, localized benefit to the target area of application. They have restorative & calming properties & can be used effectively with massage & beauty therapy. They are also natural disinfectants. The chemical structure of essential oils also allows them to be absorbed into the bloodstream via the skin for internal benefit throughout the body.

Essential oils can also be used as dietary supplements supporting a variety of healthy conditions. Some essential oils have powerful antioxidant properties while others help support healthy inflammatory response in cells. Many essential oils are generally regarded as being safe for dietary use, but some oils should not be taken internally. Do not use any essential oil product internally that does not have the appropriate dietary supplement facts on its label. Using essential oils can be both profoundly simple & life changing at the same time. Working with someone who has used essential oils before will help first-time users have a more beneficial & enjoyable experience. A large amount of information is readily available for those desiring to increase their knowledge of essential oil applications.


Please be advised

Be sure to use only 100 percent pure, therapeutic-grade essential oils & follow all label warnings & instructions. Essential oils should not be used in the eyes, inside the ear canal or in open wounds. If redness or irritation occurs when using essential oils topically, apply any vegetable oil, such as fractionated coconut oil or olive oil, to the affected area. Consult your physician before using essential oils if you are pregnant or under a doctor’s care.


Extracting the oil

Therapeutic-grade essential oils are most often extracted via a low-heat steam distillation process in which steam is circulated under pressure through plant material, liberating the essential oils into the steam. As the steam mixture cools, the water & oils naturally separate & the oil is collected in its pure form.

To ensure the highest quality oil extract with correct chemical composition, temperature & pressure must be monitored very closely. Too little heat & pressure will not release the valuable oil, while too much can change an extract’s composition & potency.

Plant species

As important as the meticulously controlled extraction process is, the careful selection of the correct plant & plant parts harvested at the right time is also required for a successful extraction. This complex process is as much art form as it is science & requires experienced growers & distillers working together to ensure a quality product.

It takes as much as 12,000 rose blossoms to distill 5 mL of therapeutic-grade essential Rose oil. Steam distillation is by far the most common method of extraction, but some oils such as citrus oils are extracted through a process of compression in which the oil is squeezed from the plant.

The importance of purity

There are a growing number of products claiming either to be or to contain essential oils. They range in price & quality & are found in skin care, cosmetics, aromatherapy & other products. However, many of these products do not use 100 percent pure essential oils & often use fragrant synthetic chemical substitutes to dilute or replace more expensive essential oil extracts. Furthermore, there are no current regulatory standards for the descriptive use of the “therapeutic grade” for products labeled as essential oils.

Therapeutic-grade essential oils are 100 percent pure, natural aromatic compounds carefully extracted from plants. They do not contain fillers or artificial ingredients that would dilute their active qualities. Proper extraction & quality control methods also ensure that therapeutic-grade essential oils are free of any contaminants, such as pesticides or other chemical residues.

Using the plant precisely

In addition to being 100 percent pure & natural, therapeutic-grade oils are subjected to additional quality testing that ensures the correct composition of the active natural compounds found in each oil. However, an essential oil cannot simply be “100 percent pure.” The correct species must be obtained, and the right part of the plant must be used. The plant must be grown in the right environment, harvested at the right time, and distilled under controlled conditions. If all these factors are not carefully accounted for, the natural chemical makeup of the extraction will not provide as predictable & powerful a benefit.

In some cases, the wrong plant part harvested at the wrong time may even result in an extract that contains harmful levels of some constituents! Look for an essential oil that is subjected to rigorous mass spectrometry & gas chromatography testing to ensure extract composition & activity.