Essential oils and fragrance oils

There is often a lot of discussion about essential oils and fragrance oils, and which are safer for use. In this article we will try to dispel some of the common myths surrounding this topic.

What is an ‘essential’ oil?

The first thing to note is that ‘essential’ oils are not essential – we can live without them, but they are perhaps ‘nice to have’.

The term ‘essential oil’ is used to cover hydrocarbons, including terpenes, typically extracted from plants by steam or water distillation. They are concentrated extracts of the plant, and are complex and variable mixtures of many different chemicals. For example, over 50 different chemical components have been identified in lavender oil. These are mostly defined as a single UVCB substance (unknown, variable or chemical of biological origin).

Different varieties of plants may contain slightly different combinations of substances, and have different levels of the same substances, meaning different sources of lavender oil, or eucalyptus oil can have different compositions. Essential oil compositions can also vary depending on what the weather was like that year while they were growing, when they were harvested, and so on.

What is a fragrance oil?

Fragrance oils are blends of natural and/or synthetic fragrances.

The natural components may be essential oils, but they can also be extracts of natural plants obtained using various solvents, or other processing methods. Not all naturally occurring fragrances can be extracted as essential oils.

Fragrance oils are often produced to have a specific scent that may mimic a natural scent, e.g., lavender, or it may mimic a particular smell that doesn’t occur naturally in plants, such as “apple spice” or “ocean breeze”. Fragrance oils are often blended with an inert carrier oil as the base.

Fragrance oils tend to be cheaper and more consistent than essential oils.

Essential oils are natural, whilst fragrance oils contain lots of chemicals so they must be worse, mustn’t they?

The different components of essential oils are all chemicals too – chemicals make up everything! Your body doesn’t care if a particular chemical was created in a plant cell or in a factory. However that particular chemical was created, your body will process it in exactly the same way.

People often point out that a particular essential oil may have healing properties, and the fragrance oil may not. Don’t forget that the essential oil contains many different chemicals, and the chemicals responsible for the healing properties may not always be the same ones that give it its smell.

It’s also worth remembering that plants don’t produce fragrant compounds just because we like the smell. They are produced either to repel insects/birds/animals so that they don’t get eaten, or to attract insects/birds/animals so that specific parts of them do get eaten, such as pollen or fruits to ensure pollination and dispersal of seeds. Many components of essential oils are, therefore, biologically active.

Many components found in essential oils are hazardous in their pure form, and, if present in an essential oil above thresholds of concern, may result in the essential oil also being classified as hazardous. Some people find it difficult to believe that naturally occurring substances can be hazardous, however, it is the dose that makes the poison, as the saying goes. Essential oils are highly concentrated, so that each drop of the oil will contain a much bigger dose of potentially harmful components than you would be exposed to if you were to simply brush past or smell a flower or leaf.

Synthetic chemicals, on the other hand, are usually much more consistent in their composition, and it can be much easier to control the level of harmful substances during their manufacture to ensure that they remain below levels of concern.

What sort of hazards might an essential oil or fragrance oil have?

Essential and fragrance oils can have many different hazards. The most common hazards found in these sorts of oils are flammability (they catch fire easily), irritants (things that can cause redness, stinging, etc of your eyes or skin), sensitisers (things that can cause an allergic reaction) and environmental hazards (things that can affect aquatic organisms like fish).

Some essential oils and fragrance oils can have more serious hazards, such as having a toxic effect on unborn, developing babies. There are very strict rules about placing products that may have such serious effects on the market, especially for products that may be used by consumers.

For general products such as candles and reed diffusers, chemical labelling rules apply and you may see red bordered hazard warning diamonds, and associated phrases that are used on labels, such as “may cause an allergic skin reaction”.

Some essential oils are marketed as cosmetics, and strict rules apply here too, requiring safety assessments and suitable warnings to be given on the labels if needed, e.g. “not to be used directly on the skin”, or “not to be used by pregnant women”. If claims of medicinal effects are made, the essential oil may need to be licenced as a medicine; if claims are made of repellent effects, e.g. for use as an insect repellent, this may require approval under biocides regulations, and so on.


Essential oils and fragrance oils both have their place in creating fragranced products, depending on what properties are desired. Neither is “better” than the other, and both can be hazardous if they contain hazardous components above levels of concern. When using these products check labels carefully and follow instructions to make sure that you use them safely.