Citronella oilCitronella oil is an

essential oil An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the ...

obtained from the leaves and stems of different species of '' Cymbopogon'' (lemongrass). The oil is used extensively as a source of perfumery chemicals such as citronellal, citronellol, and

geraniol Geraniol is a monoterpenoid and an alcohol. It is the primary component of citronella oil and is a primary component of rose oil and palmarosa oil. It is a colorless oil, although commercial samples can appear yellow. It has low solubility i ...

. These chemicals find extensive use in soap, candles and

incense Incense is an aromatic biotic material that releases fragrant smoke when burnt. The term is used for either the material or the aroma. Incense is used for aesthetic reasons, religious worship, aromatherapy, meditation, and ceremonial reasons. It ...

, perfumery, cosmetic, and flavouring industries throughout the world. Citronella oil is also a plant-based

insect repellent An insect repellent (also commonly called "bug spray" or "bug deterrent") is a substance applied to the skin, clothing, or other surfaces to discourage insects (and arthropods in general) from landing or climbing on that surface. Insect repellent ...

and has been registered for this use in the United States since 1948. The

United States Environmental Protection Agency The Environmental Protection Agency (EPA) is an independent agency of the United States government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it began operation on De ...

considers oil of citronella as a biopesticide with a non-toxic mode of action. Citronella oil has strong

antifungal An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious systemic infections such as ...

properties.

Types

Citronella oil is classified in trade into two chemotypes:Chang, Yu Shyun, 2007, ''8 Map species from Malaysia for ICS,'' Forest Research Institute Malaysia, Workshop on NFP, 28–29 May 2007, Nanchang, PR China

Ceylon type

* CAS: 89998-15-2 * CAS: 8000-29-1 * EINECS: 289-753-6 * FEMA: 2308 * CoE: 39 * Obtained from: '' Cymbopogon nardus'' Rendle * Main components: citronellal (5–15%),

(18–20%) and geranyl acetate (2%), citronellol (6–8%),

limonene Limonene () is a colorless liquid aliphatic hydrocarbon classified as a cyclic monoterpene, and is the major component in the essential oil of citrus fruit peels. The (+)-isomer, occurring more commonly in nature as the fragrance of oranges, ...

(9–11%), and methyl isoeugenol (7–11%).

Java type

* CAS: 91771-61-8 * CAS: 8000-29-1 * EINECS: 294-954-7 * FEMA: 2308 * CoE: 2046 * Obtained from: ''

Cymbopogon winterianus ''Cymbopogon winterianus'', common name Java citronella, is a perennial aromatic plant from the family Poaceae, originating in western Malesia Malesia is a biogeographical region straddling the Equator and the boundaries of the Indomalayan ...

'' Jowitt * Main components: citronellal (32–45%),

(21–24%) and geranyl acetate (3–8%), citronellol (11–15%),

(1–4%). The higher proportions of citronellal and

in the Java type oil make it a better source for perfumery derivatives. The standard quality of Java type from Indonesia is regulated by Indonesian authority under SNI 06–3953–1995, which requires citronellal minimum 35% and total geraniol minimum 85%. Both types probably originated from Mana Grass of Sri Lanka, which according to Finnemore (1962) occurs today in two wild forms – ''Cymbopogon nardus'' var. ''linnae (typicus)'' and ''C. nardus'' var. ''confertiflorus''. Neither wild form is known to be used for distillation to any appreciable extent. Citronella oil from '' Cymbopogon'' species should not be confused with other similar lemony oils from '' Corymbia citriodora'' and '' Pelargonium citrosum''.

Insect repellent

Citronella oil is used especially as a

mosquito Mosquitoes, the Culicidae, are a Family (biology), family of small Diptera, flies consisting of 3,600 species. The word ''mosquito'' (formed by ''Musca (fly), mosca'' and diminutive ''-ito'') is Spanish and Portuguese for ''little fly''. Mos ...

repellent, particularly for ''

Aedes aegypti ''Aedes aegypti'' ( or from Greek 'hateful' and from Latin, meaning 'of Egypt'), sometimes called the Egyptian mosquito, dengue mosquito or yellow fever mosquito, is a mosquito that spreads diseases like dengue fever, yellow fever, malar ...

'' (

dengue fever Dengue fever is a mosquito-borne disease caused by dengue virus, prevalent in tropical and subtropical areas. Asymptomatic infections are uncommon, mild cases happen frequently; if symptoms appear, they typically begin 3 to 14 days after i ...

mosquito). Research also indicates that citronella oil is an effective repellent for body lice, head lice, and stable flies. A study conducted by

DARPA The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military. Originally known as the Adva ...

in 1963 determined that hydroxycitronellal was an effective repellent against both aquatic and terrestrial leeches. Citronella candles (which burn wax mixed with citronella oil) are not effective at repelling mosquitos such as Aedes aegypti, the species of mosquito responsible for spreading dengue fever, chikungunya, Zika fever, Mayaro and yellow fever viruses, and other disease agents. Although direct application of citronella oil to the skin is non-toxic, its use was not recommended as a topical

in Canada in 2006.

Health Canada Health Canada (HC; )Health Canada is the applied title under the Federal Identity Program; the legal title is Department of Health (). is the Structure of the Canadian federal government#Departments, with subsidiary units, department of the Gove ...

banned use of citronella oil as an insect repellent in 2012, but lifted the ban in February 2015.

World production

At present, the world annual production of citronella oil is approximately 4,000

tonne The tonne ( or ; symbol: t) is a unit of mass equal to 1,000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton in the United States to distinguish it from the non-metric units of the s ...

s. The main producers are

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

and

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

- producing 40 percent of the world's supply. The oil is also produced in

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

Guatemala Guatemala, officially the Republic of Guatemala, is a country in Central America. It is bordered to the north and west by Mexico, to the northeast by Belize, to the east by Honduras, and to the southeast by El Salvador. It is hydrologically b ...

Honduras Honduras, officially the Republic of Honduras, is a country in Central America. It is bordered to the west by Guatemala, to the southwest by El Salvador, to the southeast by Nicaragua, to the south by the Pacific Ocean at the Gulf of Fonseca, ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

Sri Lanka Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka, also known historically as Ceylon, is an island country in South Asia. It lies in the Indian Ocean, southwest of the Bay of Bengal, separated from the Indian subcontinent, ...

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

Jamaica Jamaica is an island country in the Caribbean Sea and the West Indies. At , it is the third-largest island—after Cuba and Hispaniola—of the Greater Antilles and the Caribbean. Jamaica lies about south of Cuba, west of Hispaniola (the is ...

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

, and

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

. The market for natural citronella oil has been eroded by chemicals synthesised from

turpentine Turpentine (which is also called spirit of turpentine, oil of turpentine, terebenthine, terebenthene, terebinthine and, colloquially, turps) is a fluid obtainable by the distillation of resin harvested from living trees, mainly pines. Principall ...

derived from conifers. However, natural citronella oil and its derivatives are preferred by the

perfume Perfume (, ) is a mixture of fragrance, fragrant essential oils or aroma compounds (fragrances), Fixative (perfumery), fixatives and solvents, usually in liquid form, used to give the human body, animals, food, objects, and living-spaces an agre ...

industry.FOODNET, The Association for Strengthening Agricultural research in Eastern and Central Africa

References

{{Reflist Biopesticides Essential oils Flavors