Clove essential oil

Clove oil is an essential oil distilled from the dried flower buds of the clove tree, Syzygium aromaticum. Most of it is eugenol, the compound behind its warm, spicy smell. The oil flavours food, mouthwashes and toothpastes, and it is traditionally used for minor inflammation in the mouth and for temporary relief of toothache, which rests on long experience alone.

Type

Essential oil

Botanical name

Syzygium aromaticum

Other names

clove bud oil

The plant

The clove tree, Syzygium aromaticum, also called Eugenia caryophyllata, is a slender, medium-sized tropical tree that originated in the Moluccas, in the east of the Indonesian archipelago. It has been cultivated for at least 2,000 years. It belongs to the myrtle family (Myrtaceae). Its dried flower buds are the familiar spice, used for example in gingerbread and in spice blends such as curry.

How the oil is made

The European Pharmacopoeia defines clove oil as the oil obtained by steam distillation of the dried flower buds. In the mid-20th-century perfume and flavour trade, bud oil was usually distilled with water instead. Steam breaks down most of the natural acetyl eugenol into eugenol, while water distillation does so only slightly. The buds were ground first and gave about 15% oil.

Bud, stem and leaf oils

"Clove oil" usually means bud oil, but oil is also distilled from the stems and the leaves of the tree, so the plant part matters when buying it.

• Stem oil is steam-distilled from the stems on which the buds grow. After redistillation it contains 90 to 96% eugenol but lacks the sweet, fresh notes of bud oil.
• Leaf oil is distilled from the leaves and twigs. It contains 82 to 88% eugenol, and most of it is used to isolate eugenol for industry.

Composition

Three components make up nearly 99% of the oil: eugenol (75–88%), acetyl eugenol (4–15%) and beta-caryophyllene (5–14%). Acetyl eugenol is partly responsible for the typical smell of bud oil, so the quality of a clove oil cannot be judged by its eugenol content alone.

Scent and uses

Clove bud oil smells spicy and warming, slightly bitter and slightly woody, like clove buds but much stronger. In perfumery it gives a sweet-spicy note and lends natural richness and body to rose, honeysuckle and other deep-sweet floral scents.

Most clove bud oil goes into flavours: spice blends, pickles, baked goods and chewing gum. Its reputation as an antiseptic has also brought it into many mouthwashes, gargles and toothpastes.

Herbal medicine

Clove oil has traditionally been applied to the skin or locally for toothache, minor infections of the mouth and skin, small wounds, sore throats and coughs with colds, muscle and rheumatic pain, and insect bites.

Clove oil is traditionally used as a medicine for adults, on the basis of long experience alone. The two uses are:

• as a mouthwash with 1–5% oil, several times a day, for minor inflammation in the mouth or throat;
• on a small piece of cotton wool placed on a decayed tooth, for temporary relief of toothache.

Neither use should last more than one week. Using clove oil for toothache is only a temporary measure: a dentist should be seen as soon as possible.

Safety

• Clove oil can be very irritating to the skin. At most 0.5% on the skin is recommended. The oil should not be used at full strength.
• The concentrated oil may irritate the mucous membranes, the moist linings of the mouth and other body openings.
• Clove oil medicines can cause irritation of the mucous membranes and allergic reactions. People allergic to Peru balsam must not use them.
• An EU scientific committee lists eugenol, the main component, among the fragrance chemicals most often reported as allergens in consumers.
• Swallowed clove oil is dangerous for young children: 5 to 10 ml taken by mouth caused life-threatening conditions in children under 2.
• Clove oil medicines are not recommended for children and adolescents under 18. Their safety in pregnancy and breastfeeding has not been established, so they are not recommended then either.
• Eugenol gave equivocal results in tests for damage to genes and for cancer. The whole oil has not been properly tested for these effects or for effects on reproduction.

Products containing it

• Clove Essential Oil (E 124)
• Go Away! Oil Blend (E 146)
• Long Life “Water” Oil Blend (E 129)
• Mama Mia Aromatic Spray, Viva Plus (E 118)
• Oral Hygiene Concentrate (E 157)