Costus Oil

#### Costus Oil. **Costus Oil **is steam distilled from the comminuted, dried roots of **Saussurea Lappa**, a large impressive plant which is found growing wild in the Himalayan highlands at high altitude. The plant has been introduced in the southwestern parts of the highlands, and is found also in southern China, i.e. on both sides of the Himalaya. Only recently, the roots have been submitted to distillation in India. Earlier, the oil was produced in places outside the origin of the plant. Prior to distillation, the roots are not only comminuted, but also macerated in water. The distillation is then a combination of water- and steam-distillation. This is similar to some vetiver distillations. The oil does not separate well from the condensed water, partly because of the fact that its specific gravity is almost the same as that of water, partly because of water-solubility of certain components of the oil. The oil is actually extracted from the distillation waters by means of hydrocarbon solvents, usually benzene. (See also **Manevoro**** **oil and certain other oils which are produced in a similar way). **Costus Oil **is a pale yellow to brownish yellow, very viscous liquid. It has a peculiar soft, but extremely tenacious odor, reminiscent of old, precious wood, orris root, fatty (but not rancid) acids, vetiverol, etc., with a distinctly animal or sebaceous undertone. The odor has been compared to that of human hair, fur coats or "wet dogs". The latter description is often heard from people who smell costus oil for the first time. It is certain that not all people will like this odor. In surprisingly small concentrations, **Costus Oil **will induce warm, woody and "natural" notes to a perfume; however, this is limited to certain perfume types, e.g. Oriental bases, chypres, violet bases, certain floral fragrances, etc., and many types of the "modern-aldehydic" theme. The oil blends well with alpha-decanolide (various isomers), cinnamic alcohol, flouve oil, isoeugenol, methylionones, decylpropionate, nitromusks, patchouli, opopanax, oakmoss, etc. Overdoses of costus oil may easily produce obnoxious effects, and the power of this oil is often under-estimated. Similar in effect to angelica root oil, **Costus Oil **has the peculiar ability of producing diffusive power and intriguing topnotes, and at the same time it works effectively as a fixative of unusual tenacity. Only a good knowledge and experience, including knowledge of the botanical raw material, will enable the perfumer to choose a genuine costus oil from among the many poor ones which are offered. Although the selection of raw materials— and natural materials in particular—for the use in perfumes and flavors is mainly a matter of esthetics, it is still an advantage to know when a natural raw material is genuine and unadulterated. (See monograph Adulteration in Part One of this book). **Costus Oil **is quite expensive, and accordingly subject to frequent and extensive adulteration. **Elecampane**** **root oil, distilled from the roots of a related plant, is available in most parts of the world, and it presents certain notes which can be compared to those of costus oil. However, it does not have the typical fatty-sebaceous, animal- like notes. **Elecampane Oil**, in turn, is also adulterated (see monograph on this oil). The selection of a good costus oil thus becomes quite complicated and problematic. In spite of all this, **Costus Oil **is regularly produced in substantial quantities, estimated at 6 to 12 metric tons per year. India is the main producer, but good oils in considerable quantities are also distilled in Europe, particularly in Grasse, from Indian roots. Occasionally, the oil from Indian roots is distilled in the U.S.A. Large quantities of Indian costus root are shipped to China and other countries in the Far East for use among the population as a "factotum" remedy and house-scent. **Elecampane**** **and other, similar plants grow in China and are distilled locally. This is another source for the "on-the-spot" adulteration of costus oil. The constituents of costus oil are mainly very high boiling sesquiterpenes and sesquiterpene alcohols. Among a number of ketones found in costus oil are alpha- and beta ionone, which occur in nature very rarely (see **Boronia, Cassie, Chloranthus Spicatus, **etc.). Ketons and lactones are held responsible for the peculiar odor of costus oil. See also **Costus**** ****Absolute**, previous monograph.