Nepedia
Back to Discover
Advanced Reader
🧬

Essential oil

life science Maturity 11-13 Next article →

Essential oils are complex liquids made of hydrophobic volatile organic compounds. These compounds are obtained from various parts of plant material. The term "essential" refers to the oil containing the fragrance or essence of the plant. It does not mean the oil is a nutritional requirement for the body. These substances are also known as volatile oils or ethereal oils. They are used widely in perfumes, cosmetics, and soaps. People also use them to flavor food and drink. They can even be added to household cleaning products.

Reed diffuser
Reed diffuser

There are specific ways to produce these oils. According to ISO standards, producers use steam distillation, dry distillation, or mechanical manipulation. Mechanical manipulation is often called cold pressing. This method is used for the rinds of citrus fruits. Other methods like solvent extraction are not accepted by ISO. These other methods actually result in different products like concretes or absolutes.

Marchés des Producteurs de Pays 11 16 14
Marchés des Producteurs de Pays 11 16 14

Distillation is a common process for oils like lavender and peppermint. First, raw plant material is placed into an apparatus called an alembic. This material can include flowers, leaves, wood, bark, roots, or seeds. The alembic connects to a steam generator for indirect steam distillation. In direct steam distillation, the material is placed over water. As water heats, steam passes through the plant material. This steam vaporizes the volatile compounds. The vapors then flow through a condenser. The condenser turns the vapors back into a liquid. This liquid is collected in a receiving vessel called a florentine flask. This process also creates a fragrant water called a hydrosol. Examples of hydrosols include rose water and orange blossom water.

Citrus oils are produced through a different method called expression. This involves mechanically squeezing the citrus peel. Because citrus peels contain large quantities of oil, these oils are cheaper to produce. It is also inexpensive to grow and harvest the raw materials. Consequently, lemon and sweet orange oils are often byproducts of the citrus industry. Production volumes for these oils are quite large. Data from the 1989 to 1994 period shows sweet orange oil production reached 12,000 tonnes. Peppermint production was estimated at 3,200 tonnes. Cedarwood reached 2,600 tonnes, while lemon reached 2,300 tonnes. Eucalyptus globulus production was 2,070 tonnes. Clove leaf and Litsea cubeba both reached 2,000 tonnes.

Essential oils have significant potential as natural pesticides. They can repel insects or inhibit their digestion. Some oils can even stunt growth or decrease reproduction rates in pests. These molecules are usually non-toxic to mammals. This allows them to be used as "green" pesticides. Research has studied oils like rose, thyme, and basil for this purpose. Some oils may even match the effectiveness of DEET. DEET is a common chemical used to repel mosquitoes. Because the vapor stage is short-lived, scientists use creams or polymers. These mixtures help elongate the time the oil remains effective. In the European Union, several oils are authorized for specific uses. For example, Melaleuca oil acts as a fungicide. Citronella oil is used as a herbicide.

Marchés des Producteurs de Pays 11 16 14
Marchés des Producteurs de Pays 11 16 14

Many essential oils are recognized as safe for food use. The United States Food and Drug Administration (FDA) classifies many as Generally Recognized as Safe, or GRAS. This list includes many botanical sources. For instance, Cinnamomum cassia is used for Chinese cinnamon. Mentha species are used for menthol. Citrus sinensis is used for orange. Even many spices like nutmeg and cardamom are on this list. These oils have been used as food preservatives throughout history. The GRAS classification helped formalize their use in the 20th century.

However, improper use of essential oils can cause serious harm. They can be toxic if they are ingested or absorbed through the skin. Some oils, such as tea tree oil, may cause contact dermatitis. This is a type of skin inflammation. Others, like menthol, can cause a sensation of cold followed by burning. Some oils may even cause hormone disruption. In Australia, eucalyptus oil has caused many cases of poisoning. This is especially true for children. Between 2014 and 2018, New South Wales reported 4,412 poisoning incidents.

Reed diffuser
Reed diffuser

Users should always exercise caution when handling these concentrated substances.

687 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (2)
File:Reed diffuser.jpg
Reed diffuser.jpg
File:Marchés des Producteurs de Pays 11 16 14.jpg
Marchés des Producteurs de Pays 11 16 14.jpg
More to explore

✨ What else?

Related topics you might enjoy

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.