Peter S. Abbott
Felton Grimwade & Bickford Pty Ltd is
of Bosisto’s "Parrot Brand" Eucalyptus Oil.
The eucalyptus oil industry is an important and colourful part of
It began in 1852 in
Eucalypts, which are evergreen, form about three-quarters of the tree flora of
Eucalyptus are widely distributed over the Australian continent. They range from the dwarfed and stunted forms called "Mallees" to the tall trees which grow in coastal and mountainous regions. More than 600 species have been described by botanists who have provided voluminous and conflicting literature on many of the species.
The eucalyptus are a valuable source of hardwood and although the leaves of all species contain some eucalyptus oil less than 20 have enough oil of commercial value to be exploited and of these only 10 account for almost the entire world production. As a general rule good timber producing eucalypts contain very little oil and those utilised for their oil are of little use as timber.
All eucalyptus oils are not the same. Each species produces an oil of different chemical composition and the constituents of one oil may be completely different from an oil from another species. However, eucalyptus oil from the same species is generally remarkably constant in its constituents and chemical composition.
The eucalyptus oils of commerce can be grouped according to their uses into three classes, viz. medicinal, industrial and perfumery oils. Perfumery oils account for only a small fraction of the total usage while medicinal and industrial oils are used in about equal proportions.
The eucalyptus oil industry is an important and colourful part of
The eucalyptus oil story began in 1788 with the arrival of the First Fleet and Surgeon-General John White. Within a few weeks of arriving, White recorded in his diary the presence of olfactory oil in the eucalyptus; the genus being named eucalyptus by the French botanist L’Heritier in the same year. Governor Philip sent a sample to Sir Joseph Banks. Surgeon-General White distilled a quart of oil from the "Sydney Peppermint", Eucalyptus piperita Sm., which was found growing on the shores of Port Jackson, where
When the oil was tested in
Baron Ferdinand von Meuller, the Government Botanist in
As a result of the collaboration with von Meuller the essential oil industry of
Sales were to a restricted local market until overseas interest grew sufficiently for Bosisto to begin exports to
To develop the new industry, Felton, Grimwade, Bosisto and others formed a new firm, the Eucalyptus Mallee Company and bought Antwerp Station - a property on the
The low-growing Mallee eucalyptus were particularly suitable for cropping, but the area was remote and the company found unexpected difficulties from hungry rabbits and indolent aboriginal labourers. The enterprise was held up for some months by delays in the opening of the railway from
In 1885 the Antwerp Company was merged with Bosisto’s original business and a firm called J. Bosisto and
It is difficult to be certain which was the next species to be exploited as E. globulus, E. oleosa and E. cneorifolia were distilled for commercial purposes in the early 1880’s. Many farmers in
Practically all of these species, with the exception of E. globulus, have been superseded by those giving larger yields of oil. The pioneer investigations of Baker and Smith showed that other species such as E. polybractea, E. australiana, and E. dives gave higher yields of oil of equal or better quality. It is from these latter species that the present-day Australian eucalyptus oils of commerce are produced.
The production of eucalyptus oil in the 1880’s was often carried out by aboriginals and by erstwhile miners as the goldfields petered out. It was hard work. The virgin scrub was cut by hand with slashers and special sickles. It was collected and carted by wagon to the distillery where the freshly cut leaves were dumped into vertical iron stills set into the ground below wagon level for easy filling. After steam had carried over the volatile oil the spent leaves were hoisted out by derrick and dumped on the fire whose rising column of smoke was a constant landmark.
The old distilleries were somehow kept going by pieces of wire, bits of tin, lumps of clay, and the infinite resourcefulness of the true bush workman, whose ramshackle buildings were made of hand hewn posts and roofed with branches of nearby trees.
Sales continued to increase with interest being fostered through international exhibitions. Between 1854 and 1891 Bosisto’s oil of eucalyptus was exhibited and was awarded prized in 17 international exhibitions. By the turn of the century oil was being exported to the United Kingdom, Germany, USA, Canada, South Africa, India, China, New Zealand and several countries in the Far East.
Sales were brisk following a lively promotion campaign. Bosisto’s produced an elaborate new label and a thousand circulars attesting to the powerful properties of oil of eucalyptus for "arts, manufactures, medicine and sanitary purposes" were distributed throughout the colonies and in
However, it should be pointed out that from the very beginning oil production has been a very primitive business. Even today in a few areas the distillation of the foliage is still carried out in primitive stills set here and there in the mountains.
That the industry could develop and prosper until the Second World War is due greatly to one factor. Around the turn of the century the once rich gold fields in
The gold miners found themselves without work. They had become used to the rough but free and independent life in the bush and consequently joined the eucalyptus distillers rather than seek employment in cities and towns. Things changed with World War II. The old class of distillers was gradually dying out and the younger generation would no longer accept the low wages and poor living conditions that had prevailed.
By about 1950 the cost of producing eucalyptus oil in
Labour cost, however, was not the only cause of the decline. After the Second World War there was a strong demand for Australian wheat and this induced drastic destruction of stands of high quality eucalyptus species. Improved wheat strains and modern farming machinery allowed wheat to be grown successfully on land formerly suited only for eucalyptus. The class-conscious prosperous Australian wheat farmers have always been inclined to look upon oil production as a low grade occupation. Wheat growing appeared to be more profitable than eucalyptus oil production.
By introducing mechanical harvesting and new distillation equipment the cost of production has been reduced greatly. This together with the natural advantages Australia has in having stands of eucalypts with high quality pharmaceutical oils has given the industry an opportunity to again become the dominant supplier in world trade.
It is impossible to obtain accurate information on the Australian or world production, sales and usage figures for eucalyptus oils. Even Australian import and export statistics can be misleading. The world consumption of eucalyptus oil is estimated to be about 3000 tonnes per annum. On today’s prices the ex-distillery value of this quantity of crude oil would be in excess of $15 million.
The total Australian annual production would be less than 150 tonnes and probably in the order of 125 tonnes for all types of oil. By way of contrast the total Australian production for the period 1939 - 48 has been estimated to average almost 1000 tonnes a year. It is therefore evident that the Australian industry has declined by about 85 per cent over the last 30 to 40 years. The position is even worse when it is remembered we once supplied 100 per cent of the world requirements whereas we now contribute only five per cent of the total. It would appear that we have almost managed to export the entire eucalyptus oil industry instead of retaining and developing this very Australian industry which is part of our heritage.
Because of inherent production advantages
Many countries which once imported eucalyptus oil now produce their own requirements. The major importing countries are the
It would appear that practically all buyers for manufacturers are more interested in the smell and colour of the oil rather than the constituents, chemical composition and product benefits that may be derived from a particular species of eucalypt providing the oil being purchased meets the general specification set down for eucalyptus oil.
The most important standard in the British Pharmacopoeia is that the oil must have a minimum cineole content of 70 per cent if it is to be of pharmaceutical quality. This has lead to the position whereby eucalyptus oil of dubious origin is often blended with cineole containing substances from any source to make a concoction that the buyers find acceptable as to cineole content, smell, colour, and price. Whether it is in the best interests of the industry is a matter of conjecture.
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Eucalyptus polybractea commonly known as "Blue Mallee" is a small mallee type tree. It grows only in natural stands in the districts north and north-west of
The yield of oil from the leaves and terminal branchlets varies between 1.5 and 2.5 per cent. Young material is richer in oil and the time of year also influences the yield.
The crude oil is high in cineole and usually assays at between 80 and 88 per cent. The absence of aliphatic aldehydes contributes to the pleasant aroma of the crude oil. The crude oil which is yellow to brown becomes a pale straw colour (rarely water white) on rectification. This high quality medicinal oil is now the principal pharmaceutical grade of eucalyptus oil sold in
Eucalyptus radiata var. australiana, commonly known as "narrow-leaved Peppermint", is a medium sized tree with fibrous bark. It occurs in extensive areas in
The crude oil has a cineole content of 65 - 70 per cent and because of the terpineol and citral constituents of the oil it has a very refreshing aroma. The crude oil is usually a very pale lemon colour but is colourless on rectification. Production of this pharmaceutical grade oil has fallen as the cost of production has become too high. The leaves cannot be mechanically harvested in the same way as E. polybractea because of the steep terrain of the natural stands.
Eucalyptus dives var. "C" belongs to the "broad-leaved Peppermint" group. It is botanically identical to E. dives (type) but the oils from these otherwise identical species have no resemblance whatsoever in chemical composition. However, the oil from E. dives var. "C" and E. australiana are practically identical in chemical and physical characters. The species grows in good stands in the Tumbarumba-Tumut-Batlow district of New South Wales.
The yield of oil from the leaves and terminal branchlets varies from two to four per cent and the oil is colourless. The oil is a good quality medicinal oil.
Eucalyptus dives (type) commonly known as the "broad-leaved Peppermint" grows along the coastal ranges of
The yield of oil from the leaves and terminal branchlets varies from two to four per cent with the general average being three per cent.
The oil of this species contains 1-piperitone (40 - 50 per cent) and phellandrene (20 - 30 per cent). The oil is used industrially for the manufacture of synthetic thymol and menthol.
Eucalyptus australiana var. "B" or E. phellandra is commonly known as one of the "narrow-leaved Peppermints". It occurs extensively on the mountain ranges of
The yield of oil from the leaves and terminal branchlets averages from 3 to 4.5 per cent of a colourless to pale yellow oil. The oil consists of phellandrene (35 - 40 per cent) and cineole (20 - 50 per cent).
The oil has been extensively used for disinfectants, deodorants and many other industrial uses. It is an excellent solvent. Production has fallen dramatically as the selling price for this industrial oil has been too low to justify the hard work and high labour input required.
Eucalyptus globulus was discovered in
The yield of oil from the leaves and branchlets averages from 0.75 to 1.25 per cent. The crude oil is a mobile liquid, normally light yellow in colour, with a pronounced odour of the volatile aldehydes which causes coughing and irritation to the mucous membranes. The cineole content is between 60 - 70 per cent and since in many instances the properties of the crude oil do not meet the specifications of most pharmacopoeias the oil has to be rectified to increase the cineole content and to improve its solubility in alcohol. After rectification the oil is water-white.
Because of the volume and availability of this type of oil on the world market it has become the standard eucalyptus oil for buyers everywhere.
Eucalyptus citriodora commonly known as the "lemon scented gum". A large tree often attaining a great height with a smooth whitish pale pink bark. Readily identified by the fragrant "citronella-like" odour of the crushed leaves. It grows extensively in
The yield of oil from the leaves and terminal branchlets from forest trees varies from 0.5 to 0.75 per cent and from cultivated trees up to 2 per cent.
The principal constituent of the oil is citronellal and the oil is used for industrial and perfumery purposes. Large quantities of oil were once distilled in
Considerable improvement has been made in recent years in the harvesting, materials handling and distillation of Eucalyptus polybractea. Continued progress would give
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Eucalyptus polybractea (Blue Mallee) is the major oil producing species which can be mechanically harvested and as the species is confined to
Machine harvesting is now a tried and tested reality with all of E. polybractea being harvested in this manner.
Our method of harvesting is to use a tractor, a specially modified tritter and a mobile still in tandem. The tritter (which is akin to a forage harvester) chops the mallee off just above ground level and throws it up a chute into the mobile still which holds about three tonnes.
The old method was to lop off the limbs of growing trees or use a hand axe or special sickle to cut mallee regrowth or coppice growth which springs from the stumps of the felled trees. Once the leaves had been cut they were loaded onto a vehicle, carted to the distillery, unloaded and packed into a distillation vat where the oil was removed. The spent leaves were then unloaded and dumped in a heap ready for burning. As well as being a significant part of the cost of production, it was very labour intensive and physically demanding work.
A later method was to put the leaves and twigs into a cylindrical brick or steel vat sunk in the ground. The vats held between two and five tonnes of leaves and stalk. The whole operation was relatively inefficient and labour intensive.
When the mobile still is filled it is uncoupled and a new still attached. When two stills are filled a second tractor tows the two stills in tandem to the distillery. Lids are placed on the stills and steam is connected at the base of the stills.
After the steam vaporises the oil the vapours are condensed in modern stainless steel condensers. Cooling water is supplied from a nearby dam. The mixture of oil and water is collected in a receiver where it separates on standing as the oil being lighter floats to the surface. The yield of oil varies but averages about one per cent of the material harvested.
The boiler is fired by timber and spent leaves from previous batches. Hopefully technology will soon be sufficiently advanced to make it feasible to have the steam generated by solar heat which is available in abundance.
When the steam has carried over the oil the mobile stills are towed out for emptying of the spent leaves and this is done very simply and efficiently. The whole operation has significantly reduced the labour effort and it has been achieved at a reasonable capital cost.
The original method was to place about 400 kg of leaves in ships’ water tanks to which water was added. The tanks would then be heated with wood or spent leaves from a previous distillation. When the water boiled the steam passed through the leaves separating the oil from the plant cells and carried it over in a vaporous state into a long pipe which acted as a condenser. The pipe was attached to the still at the top and passed under the water of a stream or creek. The oil and water condensed in the pipe and flowed into a suitable receptacle where the oil floated on the surface of the water and was collected.
Most of the eucalyptus oil presently produced in
The Victorian industry is almost entirely based on the use of public land which has been under lease from either the Department of Crown Lands and Survey or the
An interesting observation is that the land on which E. polybractea has been regularly cut has the purest and healthiest stands of E. polybractea. Provided that the regrowth is properly harvested at the right time there is no evidence of damage to the plant. In fact, it appears that the plant thrives under these conditions which are not unlike the regular burning off of the old wood which used to frequently occur long before white man discovered
Fertilisation of the species has been tried but the results have not been sufficiently encouraging economically to justify further work. In addition as the fertiliser was applied on the surface of the ground it tended to be utilised by weeds and other competitors rather than by the "Blue Mallee" which is deep rooted.
Although "Blue Mallee" is subject to some insect and fungal attack the damage has never been serious enough to consider the use of pesticides to control outbreaks. There is no evidence that native flora and fauna has suffered as a result of eucalyptus oil production.
Those of us in the industry who are mindful of its future are very conscious of the need for erosion prevention. Because the land has a relatively low rainfall and because cropping leaves the land relatively bare, it is important to exercise care and to take preventative measures when and where necessary. Most erosion problems start on sloping ground where there is a hard surface. After heavy rain there is a runoff from these areas which can produce a gullying hazard and carry silt in to water ways. A historical problem is that in the old days steel-wheeled wagons were pulled along gully tracks with the result that in wet weather the wheel marks became water channels.
However, by sensible measures such as relocated roadways, leaving vegetation close to creeks and streams, not cutting leaf from bare sloping ground, not harvesting too close to the ground thereby always leaving some natural cover and perhaps by contouring where necessary, erosion problems can and are being overcome.
It has been suggested by a vocal few that the industry should be abandoned and the land should be allowed to revert to its natural state, whatever that means. It is obvious those putting forward this point of view have a very simplistic attitude toward the subject and have very little understanding of the ramifications of their suggestions or of the repercussions that would flow from the introduction of them.
As already pointed out large stands of eucalyptus were rooted out after World War II to make room for wheat crops and that the available area of E. polybractea has been depleted as a consequence. However, this type of land clearance has long since ceased and there is no chance of further "Blue Mallee" land being lost.
It is true we do not have available sufficient "Blue Mallee" stands to dramatically increase production. Nevertheless, there is enough to possibly double production. After that it will be a case of establishing plantations. Until such time as plantations have been successfully established the public land will be essential for the survival of the industry.
Perhaps when private plantations have proven to be a viable proposition it may be possible to phase out public land, but in the meantime the industry needs the use of public land in order that it can foster and nurture the development of private plantations.
The advantages to be gained by the establishment of plantations are numerous. Land would be chosen which would allow mechanical harvesting. Seed would be selected to grow vigorous plants which would give a high yield and quality of oil. Plantations would increase leaf yield per ha and planting’s would be concentrated in a given area which would reduce the cost of transportation of the leaf to the distillery. Modern and efficient distilleries could be strategically located to cater for a planned throughput.
Returns would be relatively quick for a forestry product. Harvesting would commence after one year and a reasonable return could be expected after three or four years and after five years the area planted would be in full production.
Given all these advantages why hasn’t at least one commercial plantation been established? The reason is that we have not had the technology to grow the right varieties of eucalypt for eucalyptus oil production at an economic price. The capital cost to establish a plantation is great, the problems are innumerable and the risk of failure is very high in low rainfall areas.
The first pilot plantation was started in September 1911 at Emerald,
Since 1911 a number of trial plantations have been commenced in several areas. Over many years F. H. Faulding and Co. Ltd.,
In 1972 the Australian subsidiary of the giant multinational corporation, Monsanto, looked into the feasibility of starting a plantation of Eucalyptus polybractea and concluded: "On the basis of the proposed size of the operation (2000 acres) and using proven yields the income is small compared with the money and effort expended. In addition the "pay-back" period (14 years) is long because of the need for staggered planting and a long wait before harvesting full acreage."
The Museum of Applied Arts and Sciences, Ultimo, Sydney, took a very active interest in all facets of eucalyptus oil production for more than 80 years and it was acknowledged as the leading and principal research institution in the industry, until it ceased these activities in 1980. Over the previous ten years or so, the research staff at the Museum had looked closely at the propagation and raising of E. polybractea and experimental plots have been planted since 1968. G. R. Davis and Co. near
The outcome of this experimentation has shown that:
Medicinal eucalyptus oils which are mostly used in pharmaceutical preparations must contain at least 70 per cent cineole. These oils do not contain phellandrene and must conform to the standards set out in the various pharmacopoeias. The trade supplies oil according to cineole content, i.e. 70 - 75 per cent, 80 to 85 per cent etc. To obtain these oils either an oil from a single species is used or oils from two or more species are blended. In any case it is usual to first refine the oil by rectification (re-distillation in vacuo). Rectification has these advantages. The cineole content of the oil will be increased where necessary. Residues and low boiling constituents of objectionable odour are removed. The oils are dehydrated which improves their keeping quality. The colour of the oil will be removed where necessary.
Eucalyptus oil from E. polybractea has these principal constituents: Eucalyptol (1,8 - cineole) (80 - 88 per cent), p-cymene, australol (p-isopropylphenol), cuminal, phellandral and cryptone. On the other hand eucalyptus oil from E. globulus has these principal constituents: Eucalyptol (1,8 - cineole) (60 - 72 per cent), pinene, volatile aldehydes, sequiterpenes and globulol.
Oils from other species of eucalypts have equally different constituents and therefore it is desirable to select for a particular use the type of oil with the best combination of constituents.
Medicinal eucalyptus oil produced from E. polybractea is widely used for the relief of cold and influenza symptoms. It is a unique natural product having antiseptic properties and the power to clear the nasal passages and bronchial tubes making it easier to breathe. A popular new use is to vaporise it in saunas. It is an excellent rub for muscular aches and pains and it has been widely used for many years by sportsmen to help keep muscles trim and supple. A use which is gaining widespread acceptance is the practice of adding eucalyptus oil to the laundry wash for cleaning and freshening clothes, which utilises its cleaning, deodorising and antiseptic properties.
Medicinal eucalyptus oils and eucalyptol are extensively used as a raw material and active ingredient of cough lozenges, inhalation sprays and drops, gargles, mouth washes, toothpastes, embrocation balms and ointments, liniments and soaps.
Eucalyptus oil is also used in antiseptics and germicidal disinfectants because of its pleasant odour and its effectiveness in killing bacteria. It is an excellent solvent which makes it an ideal spot and stain remover.
Industrial eucalyptus oils are used in the manufacture of household disinfectants and as an industrial solvent.
The spent leaves after the eucalyptus oil has been extracted is marketed as a mulch and ground cover. Sold under the trade-name Bosisto's Euca-Mulch, it is gaining rapid acceptance by landscape and home gardeners who like its natural appearance and bushland fragrance.
While the mulch is especially suitable for native gardens, it looks equally at home under shade, ornamental and fruit trees and in shrub and flower beds.
The mulch meets all the criteria of a first-class mulch and ground cover. It is weed and insect free and is non-toxic to animals and plants. It suppresses weed growth and reduces the need for watering. It allows excellent drainage, aeration and water penetration under all conditions. It stays in place even in very high winds and normal leaf-fall adds to its attractiveness. After 2 or 3 years it breaks down into an organic humus.
Tested by the Department of Agriculture and found to be satisfactory more work is being undertaken as it is believed the spent leaves could be an ideal addition to potting mixes.
The outlook for the future is bright. Prospects are excellent for increased exports and with the continued implementation of advances in science and technology