Editing Cedar oil (section)

== 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 ||
|}