pediaEucalyptus oil, derived from the leaves of Eucalyptus globulus Labill. (Myrtaceae family) through steam distillation, is a sharp-camphoraceous-refreshing aromatic essential oil. Its main component is 1,8-cineole (eucalyptol, 60-85%), one of the world's most widely used monoterpene oxides. Sourced from this massive tree native to Australia, eucalyptus oil ranks among the highest in volume in the global essential oil trade. It is among the rare essential oils with a monograph in pharmacopeias (BP, USP, Ph. Eur.).
This article is not a product promotion. The information contained herein does not constitute any treatment claim.
Botanical source and species
Eucalyptus genus, belonging to the Myrtaceae (myrtle) family, is a vast genus containing over 700 species. Nearly all are endemic to Australia. The primary species used for cosmetic and aromatic purposes are:
- E. globulus (blue eucalyptus): The most common commercial species. 1,8-cineole 60-85%. Pharmacopeial standard. Likely species in Chailea liquid soap.
- E. radiata: 1,8-cineole 60-70%. Softer scent. Preferred in aromatherapy.
- E. citriodora (lemon eucalyptus): Rich in citronellal. Insect repellent. Different scent profile.
Eucalyptus trees are among the world's fastest-growing trees — some species can grow 3 meters per year. In Australia, koalas feed almost exclusively on eucalyptus leaves.
Chemical profile
1,8-Cineole (eucalyptol): 60-85%
1,8-Cineole (eucalyptol, C₁₀H₁₈O) is the main component of eucalyptus oil. A monoterpene oxide, 1,8-cineole is the primary source of the fresh-camphoraceous-refreshing scent. The European Pharmacopoeia sets a standard of minimum 70% 1,8-cineole content in eucalyptus oil. This compound is also found at high concentrations in rosemary oil (ct. cineole) and bay laurel leaf oil.
Other components
α-Pinene (2-10%), limonene (1-8%), α-terpineol (1-5%), globulol (1-4%), p-cymene (1-3%), and aromatic aldehydes. Minor components contribute to the richness of the scent.
Position in scientific literature
Scientific literature and scope note
Eucalyptus oil and its main component, 1,8-cineole, have been extensively studied in pharmacology literature. Medical/pharmaceutical uses documented in this literature (oral preparations, respiratory tract applications, etc.) belong to the context of human medicinal products and fall outside the scope of this cosmetic content monograph.
Antimicrobial research
Eucalyptus oil has shown inhibitory activity against certain bacterial and fungal species in in vitro studies; 1,8-cineole contributes to this activity by affecting cell membrane structure. These findings are specific to laboratory conditions and do not constitute a product efficacy claim.
Pharmacopeial standard
Eucalyptus oil has an official monograph in the European Pharmacopoeia (Ph. Eur.), British Pharmacopoeia (BP), and United States Pharmacopoeia (USP). Pharmacopeial standards specify a minimum of 70% 1,8-cineole and a maximum of 2% camphor.
Safety profile
Eucalyptus oil is generally safe for topical use at low concentrations (1-3%). Important cautions:
- In children: At high concentrations, when applied to the face (especially around the nose), 1,8-cineole can trigger laryngospasm (throat spasm) in young children (under 3 years old). Eucalyptus oil is not recommended for children under 3 years of age.
- Epilepsy: Potential for neurotoxicity at high doses. Cautious use in patients with epilepsy.
- Oral toxicity: Ingestion is toxic — oral intake of 3.5 ml can be lethal. Keep out of reach of children.
Eucalyptus oil in soap making
Usage rate and method
Eucalyptus oil is added to soap at 3-5% during the trace stage. It is highly volatile — the scent fades over time, but 1,8-cineole has better scent retention than citrus oils.
Properties imparted to soap
Eucalyptus oil imparts a sharp, refreshing, "menthol-like" clean scent to soap. Color contribution is minimal. When combined with tea tree oil, it creates a "deep cleansing + freshness" concept — Chailea Tea Tree & Eucalyptus Liquid Soap is the result of this combination.
Compatible blends
Tea tree creates "clean-fresh", mint creates "icy refreshing", lavender creates "spa", rosemary creates "aromatic-herbal", and lemon creates "fresh-clean" combinations.
Differences among eucalyptus species
Three main eucalyptus species can be compared for cosmetic and aromatherapy use. E. globulus (blue eucalyptus) has the highest 1,8-cineole content and is the pharmacopeial standard species and most widely produced industrially. E. radiata offers a softer and more balanced scent profile, preferred by aromatherapists for sensitive skin and children. E. citriodora (lemon eucalyptus) is rich in citronellal and used in insect repellent products — its scent is distinctly different from the others. E. globulus is generally preferred in soap making.
Eucalyptus oil and increased interest during the COVID-19 period
During the COVID-19 pandemic, demand for eucalyptus oil increased globally. While 1,8-cineole has been studied in pharmacology literature, there is no clinical evidence that eucalyptus oil is effective for the treatment or prevention of COVID-19. The WHO and national health authorities have cautioned against the use of essential oils for COVID-19 treatment. Nevertheless, the pandemic accelerated the overall growth of the essential oil industry.
Eucalyptus and bee health
An interesting ecological connection: eucalyptus trees are an important nectar source, and eucalyptus honey is a sought-after honey variety worldwide. In Australia, Spain, and Portugal, eucalyptus honey production is an important source of agricultural income.
Frequently asked questions
What is eucalyptus oil?
Eucalyptus globulus leaf oil, rich in 1,8-cineole (60-85%), is a pharmacopeial essential oil obtained through steam distillation.
What is the function of eucalyptus oil in soap?
Imparts a sharp, refreshing scent to soap. Used at 3-5%. Combined with tea tree oil, it creates a "deep cleansing + freshness" concept.
Is eucalyptus oil safe for children?
Eucalyptus oil is not recommended for children under 3 years of age — high concentrations of 1,8-cineole can trigger laryngospasm. In children over 3 years, it can be used cautiously at low concentrations.
Eucalyptus oil and Spain/Portugal economy
In Europe, eucalyptus oil production is primarily conducted in Spain and Portugal. In these countries, E. globulus plantations hold economic value for both the paper-cellulose industry and essential oil production. In Turkey, eucalyptus trees are grown in limited quantities along Mediterranean coasts, but no commercial essential oil production takes place. Eucalyptus oil imports are an important item for the Turkish cosmetics and aromatherapy industry.
Chailea products containing this ingredient
- Tea Tree & Eucalyptus Liquid Soap
References
1. European Pharmacopoeia. Eucalypti aetheroleum monograph. (minimum 70% 1,8-cineole)
2. CIR — Final Report on Eucalyptus Globulus Leaf Oil as used in cosmetics. Cosmetic Ingredient Review.
3. IFRA — Eucalyptus Oil usage standards.