Citronella Oil
Oil of citronella is classed as a biopesticide because it is prepared from natural, dried, cultivated grasses. It has been used as an insect repellent for over 50 years and is the active ingredient in citronella insect repellent candles, incense sticks, and some topical skin repellent sprays, lotions and wipes. Citronella oil does not harm insects; it works by disguising the chemicals given off by humans that mosquitoes find attractive.
12 natural insect repellent towelettes. Repels mosquitoes, gnats, flies and ticks. Deet-free, contains citronella and other plant oils. Pleasant-smelling, great for travel. Up to 4 hours protection from mosquitoes and up to 2 hours from ticks.
Citronella oil has a lemony smell and is obtained from the steam distillation of freshly cut or dried grasses Cymbopogon nardus and Cymbopogon winterianus. Commercially-prepared "Ceylon" citronella oil comes from Cymbopogon nardus, and "Java" citronella is from Cymbopogon winterianus.
Citronella Insect Repellent
Although citronella oil repels mosquitoes, ticks, black flies and fleas, research suggests citronella insect repellent products vary in their efficiency and may not be as reliable or effective as other insect repellents such as DEET, picaridin and oil of lemon eucalyptus.
Fradin and Day, 2002, found the protection times of citronella-based insect repellents were not as long as insect repellents containing DEET, IR3535 and soybean oil. No citronella insect repellents tested could provide protection for more than 20 minutes.
In a laboratory evaluation of synthetic and natural mosquito repellents against three species of mosquito, Barnard and Xue, 2004, found mosquito repellent spray containing 10 percent citronella performed better overall than four other natural mosquito repellent formulations. Its protective effects were not, however, as long lasting as picaridin, soybean, IR3535, oil of eucalyptus, or DEET-based insect repellents. Average protection times for the citronella insect repellent varied greatly between mosquito species.
According to the U.S. Environmental Protection Agency (EPA), oil of citronella has been used widely since 1948 without giving cause for concern. When used according to instructions, citronella insect repellent is unlikely to be harmful to humans, domestic pets, wild animals or the environment. Skin irritation may be a concern for some people, but serious adverse effects are extremely unlikely.
For people concerned about putting chemical insect repellents on their skin, natural insect repellents containing citronella oil appear to be a safe, non-toxic, viable alternative. However, citronella insect repellents may need more frequent application than other insect repellents.
Sources:
Barnard D. and R.D. Xue. 2004. Laboratory evaluation of mosquito repellents against Aedes albopictus, Culex nigripalpus, and Ochlerotatus triseriatus (Diptera: Culicidae). Journal of Medical Entomology 41:726-730.
Fradin MS, Day JF. Comparative efficacy of insect repellents against mosquito bites. N Engl J Med. 2002; 347(1):13-8.
U.S. Environmental Protection Agency: “Active Ingredients Found in Insect Repellents”.
U.S. Environmental Protection Agency: “Citronella (Oil of Citronella) (021901) Fact Sheet”.
U.S. Environmental Protection Agency: “R.E.D. Facts: Oil of Citronella”.
