Although this essential oil has been typecast as an insect repellant (especially for malaria carrying mosquitoes), it also has great benefit in clearing the mind, refreshing rooms and for softening skin, while combating oily skin and sweaty feet.
Oil properties
Citronella oil has a slightly sweet, lemony smell.
Origin of citronella oil
It is extracted from a hardy grass, native to Sri Lanka and Java. This aromatic perennial grows about 1meter (3 feet) high and is a popular ingredient in wax candles, as an insect repellant, and is also widely used in perfumes, soaps, skin lotions and deodorants.
Extraction 
Citronella oil is extracted by the steam distillation of finely chopped fresh, dried or part-dried grass.
Chemical composition
The main chemical components of citronella oil are citronellic acid, borneol, citronellol, geraniol, nerol, citral, citronellal, camphene, dipentene and limonene.
Precautions
Citronella oil may irritate sensitive skin and cause dermatitis in certain individuals.
Therapeutic properties
The therapeutic properties of citronella oil are antiseptic, bactericidal, deodorant, diaphoretic, insecticide, parasitic, tonic and stimulant.
Uses 
Citronella oil's most useful quality is that of it being an insect repellent. It is best used in a spray, a diffuser or on a cotton ball amongst linen. It is also useful in ridding cats and dogs of fleas.
Furthermore, citronella oil helps to clear the mind and has a general toning and tonic effect on the body. It is helpful with colds, flu and minor infections and also has deodorizing qualities.
Summary
Citronella oil is not only of benefit in its use as an insecticide, but its antiseptic properties make it a great boon when wishing to clear a sickroom. It also has an excellent effect on clearing the mind. It may be used for combating excessive perspiration and for balancing oily skin, as well as fighting intestinal parasites and bringing down fever.
·    Burners and vaporizers
    In a diffuser, citronella oil can be used as an insect repellent, for colds and flu, for clearing the mind and to refresh the sickroom. In Africa, where malaria is a great problem, citronella oil is used to a great extent to keep the pesky disease carrying mosquitoes at bay.
·    In a cream or lotion
    When included in a cream or lotion, citronella oil is most useful to keep the tropical wearer safe from mosquitoes that cause  malaria. It also has a dramatic freshening effect on tired sweaty feet.
Citronella oil blends well with bergamot, geranium, lemon, orange, lavender and pine.