Citronella oil

Citronella oil is an essential oil 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. These chemicals find extensive use in soap, candles and incense, perfumery, cosmetic, and flavouring industries throughout the world.[1]

Citronella oil is also a plant-based insect repellent and has been registered for this use in the United States since 1948.[2] The United States Environmental Protection Agency considers oil of citronella as a biopesticide with a non-toxic mode of action.[3]

Citronella oil has strong antifungal properties.[4][5][6]

Types

Citronella oil is classified in trade into two chemotypes:[7]

Ceylon type

The major constituents of the Java type citronella oil

Java type

The higher proportions of citronellal and geraniol in the Java type oil make it a better source for perfumery derivatives.[1][8] 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%.[9]

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

Video tracking of a stable fly, demonstrating repellency of citronella oil [10]

Citronella oil is used especially as a mosquito repellent,[11] particularly for Aedes aegypti (dengue fever mosquito).[12] Research also indicates that citronella oil is an effective repellent for body lice, head lice, and stable flies.[10][13][14] A study conducted by DARPA in 1963 determined that hydroxycitronellal was an effective repellent against both aquatic and terrestrial leeches.[15]

Citronella candles (which burn citronella oil) are not effective at repelling mosquitoes.[16][17]

In the EU, Ceylon-type citronella oil is placed on the category 3 list, with some safety concern regarding methyl eugenol.[7] In the UK, EU legislation governing insect repellents came into force in September 2006, which banned citronella as an active ingredient in any insect repellent products.[18]

Although direct application of citronella oil to the skin is non-toxic, its use was not recommended as a topical insect repellent in Canada in 2006.[19][20] Health Canada banned use of citronella oil as an insect repellent in 2012, but later lifted the ban in February 2015.[21]

World production

At present, the world annual production of citronella oil is approximately 4,000 tonnes. The main producers are China and Indonesia - producing 40 percent of the world's supply. The oil is also produced in Taiwan, Guatemala, Honduras, Brazil, Sri Lanka, India, Argentina, Ecuador, Jamaica, Madagascar, Mexico, and South Africa.[citation needed]

The market for natural citronella oil has been eroded by chemicals synthesised from turpentine derived from conifers. However, natural citronella oil and its derivatives are preferred by the perfume industry.[22]

References

  1. ^ a b Lawless, J. (1995). The Illustrated Encyclopedia of Essential Oils. Element. ISBN 1-85230-661-0.[page needed]
  2. ^ "U.S. EPA Citronella Factsheet" (PDF). Retrieved June 9, 2014.
  3. ^ "EPA citronella reregistration fact sheet" (PDF).
  4. ^ Nakahara, Kazuhiko; Alzoreky, Najeeb S.; Yoshihashi, Tadashi; Nguyen, Huong T. T.; Trakoontivakorn, Gassinee (October 2003). "Chemical Composition and Antifungal Activity of Essential Oil from Cymbopogon nardus (Citronella Grass)". Japan International Research Center for Agricultural Sciences. 37 (4): 249–52. INIST 15524982.
  5. ^ Pattnaik, S; Subramanyam, VR; Kole, C (1996). "Antibacterial and antifungal activity of ten essential oils in vitro". Microbios. 86 (349): 237–46. PMID 8893526. INIST 3245986.
  6. ^ Prabuseenivasan, Seenivasan; Jayakumar, Manickkam; Ignacimuthu, Savarimuthu (2006). "In vitro antibacterial activity of some plant essential oils". BMC Complementary and Alternative Medicine. 6: 39. doi:10.1186/1472-6882-6-39. PMC 1693916. PMID 17134518.
  7. ^ a b 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 "Archived copy" (PDF). Archived from the original (PDF) on 2007-07-16. Retrieved 2007-09-06.((cite web)): CS1 maint: archived copy as title (link)
  8. ^ Online referenced article, Torres, R.C., Tio, BDJ, Citronella oil industry: challenges and breakthroughs [1] Archived 2004-03-12 at the Wayback Machine
  9. ^ IOP Conference Series: Materials Science and Engineering - "Essential Oil Extraction From Citronella Stems (Cymbopogon winterianus) By Vacuum Distillation" https://iopscience.iop.org/article/10.1088/1757-899X/1053/1/012119/pdf
  10. ^ a b Baldacchino, Frédéric; Tramut, Coline; Salem, Ali; Liénard, Emmanuel; Delétré, Emilie; Franc, Michel; Martin, Thibaud; Duvallet, Gérard; Jay-Robert, Pierre (2013). "The repellency of lemongrass oil against stable flies, tested using video tracking". Parasite. 20: 21. doi:10.1051/parasite/2013021. PMC 3718533. PMID 23759542.
  11. ^ Kim, Jeong-Kyu; Kang, Chang-Soo; Lee, Jong-Kwon; Kim, Young-Ran; Han, Hye-Yun; Yun, Hwa Kyung (2005). "Evaluation of Repellency Effect of Two Natural Aroma Mosquito Repellent Compounds, Citronella and Citronellal". Entomological Research. 35 (2): 117–20. doi:10.1111/j.1748-5967.2005.tb00146.x. S2CID 85112045.
  12. ^ Trongtokit, Yuwadee; Rongsriyam, Yupha; Komalamisra, Narumon; Apiwathnasorn, Chamnarn (2005). "Comparative repellency of 38 essential oils against mosquito bites". Phytotherapy Research. 19 (4): 303–9. doi:10.1002/ptr.1637. PMID 16041723. S2CID 23425671.
  13. ^ Mumcuoglu, Kosta Y.; Galun, Rachel; Bach, Uri; Miller, Jacqueline; Magdassi, Shlomo (1996). "Repellency of essential oils and their components to the human body louse, Pediculus humanus humanus". Entomologia Experimentalis et Applicata. 78 (3): 309–14. doi:10.1111/j.1570-7458.1996.tb00795.x. S2CID 84889511.
  14. ^ Mumcuoglu, KY; Magdassi, S; Miller, J; et al. (2004). "Repellency of citronella for head lice: Double-blind randomized trial of efficacy and safety". The Israel Medical Association Journal. 6 (12): 756–9. PMID 15609890.
  15. ^ "Dtic.mil" (PDF). Archived from the original (PDF) on 18 April 2015.
  16. ^ Pearson, Gwen (2017-02-16). "Want to repel mosquitoes? Don't use citronella candles". Science. doi:10.1126/science.aal0773. ISSN 0036-8075.
  17. ^ "Micro Wave: Why Mosquitoes Bite You More Than Your Friends". NPR.org.
  18. ^ "HSE Biocides Unit responds to The Daily Telegraph article" 13 October 2006 Archived 2011-03-11 at the Wayback Machine
  19. ^ "Citronella FAQs". CBC. 26 September 2006.
  20. ^ Bond C, Buhl K, Stone D (2013). "Oil of citronella: General fact sheet". US National Pesticide Information Center, Oregon State University Extension Services. Retrieved 6 November 2023.
  21. ^ Harris, Sophia (19 February 2015). "Citronella bug spray makes comeback after public pressure". CBC. Retrieved 6 November 2023.
  22. ^ FOODNET, The Association for Strengthening Agricultural research in Eastern and Central Africa "FoodNet | Market Information | Tropical Commodities | Commodities C 1". Archived from the original on 2012-08-03. Retrieved 2008-04-13.