Eucalyptus oil is obtained from eucalyptus leaves. Its best-known use is for vapor rubs and in nasal sprays for people suffering from colds. The oil is also used to make a variety of other products, including disinfectants, liquid soaps, lozenges, perfumes, and synthetic menthol.
Less than a dozen of the many species (kinds) of eucalyptus trees are used to make oil commercially. The blue mallee is the most important commercial species.
To produce the oil, processors cut leaves from the trees and pack them into a still. They steam the leaves until the oil vaporizes from the leaf tissues. The mixture of steam and oil vapor passes from the still into a condenser, where it is cooled and turns back into liquid. The oil floats on the water and can then be skimmed off. Distillation takes from 2 to 18 hours.