In November 1788, some ten months after the establishment of the colony of New South Wales, 1 quart (roughly 1 liter) of the steam distilled leaf oil of the Sydney peppermint gum, Eucalyptus piperita, was sent to England by John White, Surgeon-General to the Colony, thus laying claim to being the first useful natural product produced in Australia. In 1852, at the prompting of the botanist Baron Ferdinand von Müller, the English pharmacist Joseph Bosisto started commercial production of eucalyptus oil at Dandenong near what is now Melbourne. The eucalyptus oil industry continued to expand and Australia remained the world’s largest supplier of eucalyptus oil well into the first half of the 20th century.
The development of the infant Australian essential oil, and in particular of the eucalyptus oil, industry was adversely affected by several problems, the chief of which was the variable quality of the oils traded. There were several reasons for this unsatisfactory state of affairs, such as:
- The botanical classification of the novel, unusual and often very complex Australian flora was only in its beginnings – which led to confusion and uncertainty in the identity of the species distilled (it should be noted that at the present time there are in the family Myrtaceae alone close to 1000 species of Eucalyptus, at least 230 species of Melaleuca, 80 species of Leptospermum, etc and the numbers are still growing).
- Large variations in the quantitative composition of essential oils from the same botanical species, including the existence of chemical varieties (the “physiological forms” of Penfold and Morrison).
- The worldwide lack of knowledge of the chemistry of terpenoids, a class of often unstable and occasionally complex essential oil constituents, which seriously hampered the researches of early essential oil chemists.
The situation improved through the efforts of the German pharmacist and botanist Baron Ferdinand von Müller, appointed in 1853 Government Botanist of Victoria. His vast contribution to botanical knowledge of the Australian flora, particularly that of south eastern Australia as well as that of other botanists such as J. H. Maiden, W. F. Blakely etc. was extended in the early 1900’s by workers at the Museum of Applied Arts & Sciences in Sydney, namely the chemist H. G. Smith and the botanist R. T. Baker and some twenty years later the chemists A. R. Penfold and F. R. Morrison.
These advances in botanical as well as in chemical knowledge led to an increase in the search for useful oils from the vast Australian essential oil flora and thus to the expansion of the Australian essential oil industry.
Medicinal oils: eucalyptus oils rich in 1,8-cineole have been distilled on a large scale from Eucalyptus polybractea, Eucalyptus radiata subsp. radiata (known in the trade as “Eucalyptus australiana“), Eucalyptus dives var. C and several other species, mainly in N.S.W. and Victoria. The medicinally active constituent is 1,8-cineole (syn.: eucalyptol).
These oils are used in various pharmaceutical preparations, as inhalants etc. The leaf oils of the terpinen-4-ol rich varieties of Melaleuca alternifolia and Melaleuca linariifolia, growing in coastal central and northern NSW, are bactericidal and have been used as antiseptics. The Western Australian sandalwood oil from Santalum spicatum was once used extensively for medicinal purposes (as a bactericide). It has been produced in Western Australia from the 1880’s onwards. Its production increased from about 1.5 tonnes in 1920 to about 54 tonnes in 1932. It was later supplanted by the antibiotics.
Industrial oils were produced from Eucalyptus dives “type” and from Eucalyptus radiata subsp. radiata (also known as ” Eucalyptus phellandra “) and Eucalyptus dives var. A. All three species have been distilled in southern N.S.W. and in Victoria. The laevo-piperitone rich E. dives “type” oil has been a valuable source of laevo-piperitone which has been used in the commercial production of laevo-menthol and thymol. All these oils, but particularly the phellandrene-rich oils from E. dives type and E. australiana, are excellent paint removers and solvents for grease, fats and oils. The cineole-rich eucalyptus oils are likewise very good grease removers and have been used for that purpose.
Perfumery oils: Western Australian sandalwood oil (from Santalum spicatum ) was used in a small way as a fixative in perfumes. Boronia Absolute Otto was produced from the flowers of the Western Australian Boronia megastigma. Boronia perfume and boronia scented cosmetics have been produced by the Perth firm Plaimar in the 1920’s.
Small amounts of Eucalyptus citriodora (now renamed Corymbia citriodora) leaf oil, Leptospermum citratum (now renamed Leptospermum petersonii) leaf oil and the somewhat rose-scented Eucalyptus macarthurii oil (both leaf as well as bark) have also been produced.
Post-world War II to present day developments
Early essential oil producers collected foliage from natural stands. This proved to be uneconomical as labour costs were too high as well as being ecologically unsustainable. In order to remain competitive essential oil producers turned to plantation grown plant material. Selection of the plants grown as well as mechanisation of the whole production process (planting, harvesting, oil extraction) was found to be essential for profitable essential oil production.
An early example was the successful establishment of a French lavender ( Lavandula angustifolia ) plantation by the Denny family in Tasmania during the immediate post world war II years.
Whilst the production of piperitone type eucalyptus oils has ceased owing to the discontinuation of the synthetic menthol industry, the bulk of eucalyptus oil produced at the present time is of the 1,8-cineole type from Eucalyptus polybractea and to a much smaller extent of Eucalyptus radiata subsp. radiata. Some cineole-type oil is also produced in Western Australia from Eucalyptus plenissima, Eucalyptus polybractea and several other mallee species. In almost all cases the trees harvested are plantation grown.
The major Australian essential oil is at the present time Tea Tree oil produced from Melaleuca alternifolia and to a smaller extent from Melaleuca linariifolia and Melaleuca dissitiflora. Tea tree oil is used mainly as a cosmetics additive.
Minor essential oils produced at the present time are from: Melaleuca quinquenervia(nerolidol type), Backhousia citriodora, Anetholea anisata (previously known as Backhousia anisata), Leptospermum petersonii, Eucalyptus olida, Eucalyptus staigeriana, Callitris intratropica as well as Santalum spicatum. There is also a small production of Boronia megastigma absolute.
Essential oils from introduced species include: bitter fennel oil (a major oil), peppermint oil (about 10 – 30 tonne p.a. depending on the season), dillweed oil, parsley herb oil, hop oil, sweet orange oil and lemon oil. Small amounts of various Lavandula oils are also produced (mostly lavandins).