Editing Cedar oil

{{Short description|Essential oil}}
[[File:CedarwoodEssOil.png|thumb|right|Cedarwood [[essential oil]] ]]
'''Cedar oil''', also known as '''cedarwood oil''', is an [[essential oil]] derived from various types of [[Pinophyta|conifers]], most in the [[Pinaceae|pine]] or [[Cupressaceae|cypress]] [[List of trees and shrubs by taxonomic family|botanical families]]. It is produced from the foliage, and sometimes the wood, roots, and stumps left after [[logging]] of trees for timber. It has many uses in [[art]], [[Industry (manufacturing)|industry]], and [[perfume]]ry, and while the characteristics of oils derived from various species may vary, all have some degree of [[Pesticide|pesticidal]] effects.

== Sources and characteristics ==
Although termed cedar or cedarwood oils, the most important oils are produced from [[Distillation|distilling]] wood of a number of different [[juniper]]s (''Juniperus'') and [[Cupressus|cypress]]es (''Cupressus''; both of the family [[Cupressaceae]]), rather than true [[Cedrus|cedars]] (of the family [[Pinaceae]]).<ref>[http://www.fao.org/docrep/V5350e/V5350e12.htm Chapter 10: Cedarwood Oils] {{Webarchive|url=https://web.archive.org/web/20110618030456/http://www.fao.org/docrep/v5350e/v5350e12.htm |date=2011-06-18 }}, United Nations Food and Agriculture Organization report</ref> Similar oils are distilled, pressed or chemically extracted in small quantities from wood, roots, and leaves from plants of the genera ''[[Platycladus]]'', ''[[Cupressus]]'', ''[[Taiwania]]'', and ''[[Calocedrus]]''.

One of the elements found in many cedar trees is [[cedrol]]. The amount of cedrol in a species of cedar affects its pesticidal effect on insects. As part of [[ancient Egyptian funerary practices]], cedar oil was used in [[embalming]], which in effect helped to keep insects from disturbing the body.

Cedarwood oil is a mixture of organic compounds considered generally safe by the [[US Food and Drug Administration|FDA]] as a food additive [[preservative]]. The [[US Environmental Protection Agency|United States EPA]] "does not expect [toxic] effects to occur among users of currently registered cedarwood oil products" because their use and public exposure is at a lower level and more intermittent than in case studies (e.g., U.S. National Toxicology Program<ref>{{cite report |date=2016 |title=Toxicity Studies of Cedarwood Oil (Virginia) Administered Dermally to F344/N Rats and B6C3F1/N Mice |publisher=United States Department of Health and Human Services |doi=10.22427/NTP-TOX-86 |issn=2378-8992|doi-access=free |pmc=8039887 }}</ref>). The EPA believes there is negligible human and environmental risk posed by exposure to registered cedarwood pesticide if used in properly prescribed manner.<ref>{{cite web |date=1993 |title = Wood oils and gums (Cedarwood oil) |url=https://www3.epa.gov/pesticides/chem_search/reg_actions/reregistration/fs_PC-040505_15-Mar-99.pdf |publisher=United States Environmental Protection Agency |id=EPA-738-F-93-008}}</ref>

All the cedarwood oils of commerce contain a group of chemically related compounds, the relative proportions of which depend upon the species from which the oil is obtained.<ref name=NTP>{{Cite book |url=https://ntp.niehs.nih.gov/ntp/htdocs/chem_background/exsumpdf/cedarwood_oil_508.pdf |title=Cedarwood Oil}}</ref> These compounds include [[cedrol]] and [[cedrene]], and while they contribute something to the odor of the whole oil they are also valuable to the chemical industry for conversion to other derivatives with fragrance applications. The oils are therefore used both directly and as sources of chemical isolates.

{|class="wikitable sortable"
|+Composition of some commercial and true (''Cedrus'') cedarwood oils (%)<ref name=NTP/>
|-
! Substance !! Texas !! Virginia<br>(''[[Juniperus virginiana]]'') !! Western red<br>(''[[Thuja plicata]]'') !! Deodar<br>(''C. deodara'')<ref>{{cite journal |last1=Chaudhary |first1=A |last2=Kaur |first2=P |last3=Singh |first3=B |last4=Pathania |first4=V |title=Chemical composition of hydrodistilled and solvent volatiles extracted from woodchips of Himalayan Cedrus: Cedrus deodara (Roxb.) Loud. |journal=Natural Product Communications |date=September 2009 |volume=4 |issue=9 |pages=1257–60 |doi=10.1177/1934578X0900400920 |pmid=19831040 |doi-access=free }}</ref> !! ''C. libani''<ref name="libwood">{{cite journal |last1=Saab |first1=AM |last2=Harb |first2=FY |last3=Koenig |first3=WA |title=Essential oil components in heart wood of Cedrus libani and Cedrus atlantica from Lebanon |journal=Minerva Biotecnologica |date=September 2005 |volume=17 |issue=3 |pages=159–61 |url=https://www.researchgate.net/publication/215754551 |language=en}}</ref> !! ''C. atlantica''<ref name="libwood"/>
|-
| [[Thujopsene]] || 60.4 || 27.6 || 0 ||
|-
| [[Cedrol]] || 19.0 || 15.8 || 0 || 
|-
| (−)-α-Cedrene || 1.8 || 27.2 || 0 ||
|-
| (+)-β-Cedrene || 1.6 || 7.7 || 0 ||
|-
| α-Copaene || 2.8 || 6.3 || 0 ||
|-
| [[Widdrol]] || 1.1 || 1.0 || 0 ||
|-
| Methyl thujate || 0 || 0 || 65 ||
|-
| [[Thujic acid]] || 0 || 0 || 25 || 
|-
| β-Thujaplicin || 0 || 0 || 1 ||
|-
| α-Thujaplicin || 0 || 0 || 1 ||
|}

==Uses==
{{more citations needed|section|date=May 2022}}
Cedarwood oils each have characteristic woody odours which may change somewhat in the course of drying out. The crude oils are often yellowish or even darker in color and some, such as Texas cedarwood oil (derived primarily from ''[[Juniperus ashei]]'' and ''[[Juniperus deppeana|J. deppeana]]''), are quite viscous and deposit crystals on standing. They find use (sometimes after ''[[Rectified spirit|rectification]]'') in a range of fragrance applications such as soap perfumes, household sprays, floor polishes and insecticides. Small quantities are used in microscope work as a clearing oil.

Today, cedarwood oil is often used for its aromatic properties, especially in [[aromatherapy]]; it can also be used to renew the smell of natural cedar furniture. Cedarwood oil is used as an [[insect repellent]], both directly applied to the skin and as an additive to sprays, candles and other products.

In India, oil from the deodar cedar (''[[Cedrus deodara]]'', a true cedar) has been shown to possess [[insecticide|insecticidal]] and [[Fungicide|antifungal]] properties and to have some potential for control of fungal deterioration of spices during storage.<ref>{{Cite journal |last1=Desai |first1=Avni G. |last2=Qazi |first2=Ghulam N. |last3=Ganju |first3=Ramesh K. |last4=El-Tamer |first4=Mahmoud |last5=Singh |first5=Jaswant |last6=Saxena |first6=Ajit K. |last7=Bedi |first7=Yashbir S. |last8=Taneja |first8=Subhash C. |last9=Bhat |first9=Hari K. |date=September 2008 |title=Medicinal Plants and Cancer Chemoprevention |url=|journal=Current Drug Metabolism |volume=9 |issue=7 |pages=581–591 |doi=10.2174/138920008785821657 |issn=1389-2002 |pmc=4160808 |pmid=18781909}}</ref> It is still sometimes also used to clarify [[emeralds]].<ref>{{Cite web |title=Emerald Fillers and Treatments |url=https://www.gemsociety.org/article/emerald-fillers/ |website=International Gem Society}}</ref>

== History ==

=== Cedar of Lebanon ===
[[File:Cèdre du Liban Barouk 2005.jpg|thumb|''Cedrus libani'']]
The cedarwood oil of the ancients, in particular the [[Sumer]]ians and [[Ancient Egypt|Egyptians]], was derived from the [[Cedrus libani|Cedar of Lebanon]] (''Cedrus libani''), a [[Cedrus|true cedar]] native to the northern and western mountains of the [[Middle East]]. The once-mighty Cedar of Lebanon forests of antiquity have been almost entirely eradicated, and today no commercial oil extraction is based on this species. 

=== Sumer ===
Cedarwood oil was used as the base for paints by the ancient Sumerians. They would grind [[cobalt]] [[chemical compound|compound]]s in a [[Mortar and pestle|mortar]] to produce a blue [[pigment]]. They could obtain green from [[copper]], yellow from [[antimonate|lead antimonate]], black from [[charcoal]], and white from [[gypsum]].

=== Ancient Egypt ===
One of three methods of ancient Egyptian [[embalming]] practices employs the use of cedarwood oil. This was a less costly method than the best known of the ancient Egyptian practices of removing internal organs for separate preservation in [[canopic jar]]s. The practice<blockquote>...called for the injection of cedar oil into body cavities without [[Disembowelment|evisceration]]. The body was laid in natrum or [[natron]]—a fixed [[alkali]]—for the prescribed period, after which the cedarwood oil, which had dissolved the soft organs, was released; and the body, its flesh dissolved by the natron, was reduced to preserved skin and bones.<ref>{{cite book |last1=Habenstein |first1=Robert W. |title=The History of American Funeral Directing |last2=Lamers |first2=William M. |publisher=Burton & Mayer, Inc. |year=2007}}</ref></blockquote>

=== Classical antiquity ===
[[File:Pliny_the_Elder,_Loggia_del_Consiglio,_Piazza_dei_Signori,_Verona_(37520060770)_(cropped).jpg|alt=Head of a statue of Pliny the Elder|thumb|169x169px|Pliny the Elder]]
As the Roman naturalist and author [[Pliny the Elder]] (23/24 –79 CE) in his encyclopedic work ''[[Natural History (Pliny)|Natural History]]'' ({{langx|la|Naturalis Historia}}) describes how aromatic oils are produced through the destructive distillation of pine wood, he also mentions that a similar substance, “cedrium” (cedar oil), is produced in Syria, and how it is used.<ref>{{Cite book |last=Pliny the Elder |url=https://www.gutenberg.org/ebooks/author/50041 |title=The Natural History of Pliny: Translated, with Copious Notes and Illustrations |publisher=Henry G. Bohn |year=1855 |volume=III |translator-last=Bostock |translator-first=John |chapter=XVI.21(11) |orig-date=Pliny published the first 10 books in 77 CE. The rest was published posthumously by Pliny the Younger |translator-last2=Riley |translator-first2=Henry Thomas |chapter-url=https://www.gutenberg.org/cache/epub/59131/pg59131-images.html#BOOK_XVI_CHAP_21}}</ref>{{Blockquote|text=In Europe, tar is extracted from [''[[Pinus mugo]]''] by the agency of fire. ... The first steam that exudes flows ... into a reservoir made for its reception: in Syria this substance is known as “cedrium”; and it possesses such remarkable strength, that in Egypt the bodies of the dead, after being steeped in it, are [[Mummy|preserved from all corruption]].}}

=== Light microscopy ===
Until the development of synthetic [[immersion oil]] in the 1940s, cedarwood oil was widely used for the oil immersion objective in [[optical microscope|light microscopy]]. 

== Notes ==
{{Reflist}}

[[Category:Painting materials]]
[[Category:Essential oils]]