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What’s Inside Counts

Nature’s own antidotes and assassins

When you think of essential oils, weapons are probably not the first things that spring to mind. But in the right concentrations, essential oils can be lethal or lifesaving.

Essential oils are made up of naturally occurring chemicals some are toxic, some are beneficial when applied to skin and some are the foundation of modern pharmaceuticals. Knowing the difference is crucial! Here are some worth knowing about.


Coumarin is a fragrant chemical compound that occurs naturally in a number of plants, including vanilla, cinnamon and tonka. It is revered for its sweet, spicy fragrance and taste, and is used by perfumers and chefs alike.

Coumarin is the chemical responsible for the smell of freshly cut grass. Much more than just a pretty smell, coumarin was a precursor to warfarin – a drug used to thin blood and reduce the chances of clotting. The United States restricts use of the tonka bean in food because it contains a high concentration of coumarin and could potentially react with other medications. At least 30 tonka beans would be needed to reach toxic levels.

Benzyl alcohol

Benzyl alcohol is a colorless, aromatic liquid found in plants, fruits, and, by extension, essential oils. It is used in flavorings and in cosmetics, but has many other uses. Its antibacterial properties make it a useful natural preservative, as well as a local anesthetic.

Benzyl alcohol can be derived from roses, lavender, citrus fruits, jasmine and ylang ylang, but is also often synthesized (made in a lab). Benzyl alcohol can be an irritant to the skin in doses above 3%, so its use in cosmetics and perfumery is carefully regulated. In higher concentrations benzyl alcohol is used in insect repellents, paint strippers and varnishes.

Amygdalin (and cyanide)

Amygdalin is a naturally occurring chemical compound found in bitter almond kernels. Its presence helps to protect precious almond seeds from being eaten by insects and other organisms. This is because the chemical becomes toxic when crushed, mixing with an enzyme and producing lethal cyanide – a name you’ll recognize from many a murder mystery. Amygdalin is also present in other fruit seeds including apples, apricots, peaches and plums.

In order to safely obtain almond essential oil from bitter almonds the cyanide must be thoroughly washed away. Another way to ensure safety is to use sweet almonds, which don’t pose a risk.


Clove, cinnamon, nutmeg and ginger – it might sound like a Christmas spice sensation, but in fact, these natural seeds, barks and roots contain a high proportion of the chemical compound eugenol. Eugenol is used in local anesthetics, antiseptics, antibacterial agents and as a pain reliever. It is also used in dental preparations and treatments – explaining that clove taste you may associate with trips to the dentist.

Eugenol also plays a role in the plant world. The bulbophyllum orchid releases methyl eugenol to encourage fruit flies and bees to pollinate its flowers.

In high concentrations eugenol can be toxic, and its use is restricted in perfumery. Just 0.02% of any fine fragrance can contain eugenol. This is to prevent any reactions your skin may have to the naturally occurring chemical.


Geraniol is an organic compound and alcohol that occurs naturally in essential oils, particularly rose and citronella, but also chamomile, clary sage, lavender and neroli. Its rose-like aroma and sweet taste mean it’s a common ingredient in perfumery and also in food flavorings.

Geraniol also plays a huge role in the ecosystem. Bees collect the chemical from the flowers, which is then concentrated in their bodies. Honeybees then secrete geraniol from their scent glands to mark nectar-producing flowers and to locate the entrances of their hives.

As an alcohol, some people are sensitive to geraniol, which means its use in fragrance is carefully regulated.


Farnesol is a naturally occurring colorless liquid extracted from a variety of plants and natural sources, including neroli, tuberose and sandalwood. It is often used in perfumery for its delicate floral scent, but also lays claim to antimicrobial properties. For this reason, farnesol is a common ingredient in acne treatments as it’s particularly good at fighting the bacteria responsible for acne – Propionibacterium.

In the natural world, farnesol is used as a pheromone by female mites to attract males to mate with them. Because it has such an effect on mite behavior, farnesol is also added to pesticides.

Harnessing nature’s power

Essential oils can be dangerous. As natural ingredients, there is a fine line between safe and harmful. Lush has an in-house team who are responsible for understanding and regulating the quantities of chemicals in any given oil or perfume, as well as the level of allergens in a product. Tools like a Gas Chromatography Mass Spectrometry (GCMS) machine can show and essential oils chemical makeup.

The team ensure that all new inventions and products contain safe levels of essential oils – and the chemicals within them. This means carefully looking at the constituents of each oil to see what they are made of and ensuring that when two or three – or more – oils are mixed in a product formula the chemicals do not exceed safe levels.

Regulating essential oils

These kind of safety considerations are regulated by the International Fragrance Association (IFRA). IFRA regulations are split into 11 different categories based on the purpose of a product and how it interacts with the skin. This means a shower gel and a moisturizer can contain different qualities of essential oil because one is washed off, while the other is left to soak into skin.

So, although essential oils are natural, that doesn’t mean they’re guaranteed to be safe: that all depends on how they are used and handled. Beneath the beautiful blends and alluring aromas, an entire world of science awaits, and it’s essential to ensuring the oils in the products you use every day are the safest and most effective they can be.