View source for Candle

{{short description|Wick embedded in solid flammable substance}}
{{Other uses}}
{{pp-semi-indef}}
[[File:LA2 Skultuna kontorsljusstake.jpg|thumb|A candle in a candle stick]]
[[File:ISR-2013-Jerusalem-Church of the Holy Sepulchre-Candles.jpg|thumb|Tapers (long thin candles) in a church]]
[[File:Yahrtzeit candle.JPG|thumb|A [[memorial candle]] (yahrtzeit candle)]]

A '''candle''' is an ignitable [[candle wick|wick]] embedded in [[wax]], or another flammable solid substance such as [[tallow]], that provides [[light]], and in some cases, a [[Aroma compound|fragrance]]. A candle can also provide [[heat]] or a method of keeping [[time]]. Candles have been used for over two millennia around the world, and were a significant form of indoor lighting until the invention of other types of light sources.  Although [[electric light]] has largely made candle use nonessential for illumination, candles are still commonly used for functional, symbolic and aesthetic purposes and in specific cultural and religious settings.

Some early candles were made of [[beeswax]], but these candles were expensive and their use was limited to the elite and the churches. Tallow was a cheaper but less aesthetically pleasing alternative. In the modern era, various materials have been developed for candle making, including [[paraffin wax]]. This, combined with efficient production techniques, made candles affordable for the general public.   Various devices can be used to hold candles, including [[candlestick]]s, [[candelabra]]s, [[chandelier]]s, [[lantern]]s, and [[Sconce (light fixture)|sconces]]. A person who makes candles is traditionally known as a [[chandlery|chandler]].<ref>{{cite web| url= http://www.thefreedictionary.com/chandler|title=Chandler |publisher=The Free Dictionary By Farlex|access-date=2012-05-19}}</ref>

The combustion of the candle proceeds in a self-sustaining manner.  As the wick of a candle is lit, the heat melts and ignites a small amount of solid fuel (the wax), which [[vaporizes]] and combines with [[oxygen]] in the air to form a [[flame]]. The flame then melts the top of the mass of solid fuel, which moves upward through the wick via [[capillary action]] to be continually burnt, thereby maintaining a constant flame. The candle shortens as the solid fuel is consumed, so does the wick. Wicks of pre-19th century candles required regular trimming with scissors or "[[Candle snuffer|snuffers]]" to promote steady burning and prevent smoking. In modern candles, the wick is constructed so that it curves over as it burns, and the end of the wick gets trimmed by itself through incineration by [[fire]].<ref name=candles>[http://www.eca-candles.com/design.php?rubrik=29&topnav=6&sprach_id=en&SID=ksqhyfiz European Candle Association FAQ] {{Webarchive|url=https://web.archive.org/web/20120113154928/http://www.eca-candles.com/design.php?rubrik=29&topnav=6&sprach_id=en&SID=ksqhyfiz |date=2012-01-13 }}.</ref>

==Etymology==
The word candle comes from [[Middle English]] {{lang|enm|candel}}, from [[Old English]] and from [[Anglo-Norman language|Anglo-Norman]] {{lang|ang|candele}}, both from [[Latin]] {{lang|la|candēla}}, from {{lang|la|candēre}} 'to shine'.<ref name=Farlex>{{cite web| url= http://www.thefreedictionary.com/candle |title=Candle |publisher=The Free Dictionary By Farlex|access-date=2012-05-19}}</ref>

==History==
{{Main|History of candle making}}
[[File:Bronze candelabrum MET DP250501.jpg|thumb|upright|[[Etruscan civilization|Etruscan]] [[candelabrum]] {{circa|550 BC}}]]
Prior to the invention of candles, ancient people used open fire, torches, splinters of resinous wood, and lamps to provide artificial illumination at night.{{sfn|Forbes|1966|page=[https://books.google.com/books?id=N6Y3AAAAIAAJ&pg=PA127 127] }} Primitive [[oil lamp]]s in which a lit wick rested in a pool of oil or fat were used from the [[Paleolithic]] period, and pottery and stone lamps from the [[Neolithic]] period have been found.{{sfn|Forbes|1966|page=[https://books.google.com/books?id=-VmmHdm5STIC&pg=PA126 126] }}  Because candle making requires a reliable supply of animal or vegetable fats, it is certain that candles could not have developed before the early [[Bronze Age]];{{sfn|Forbes|1966|page=[https://books.google.com/books?id=-VmmHdm5STIC&pg=PA134 134]}} however, it is unclear when and where candles were first used. Objects that could be candlesticks have been found in [[Babylonia|Babylonian]] and middle [[Minoan civilization|Minoan]] cultures, as well in the [[tomb of Tutankhamun]].{{sfn|Baur|1996|page=7}} The "candles" used in these early periods would not have resembled the current forms; more likely they were made of plant materials dipped in animal fat.<ref name=hellenic>{{cite web |url=https://www.hellenic.org.au/post/let-there-be-light |title=Let There be Light: A History of Candles |work=Hellenic Museum |date=3 December 2021 }}</ref>

Early evidence of candle use may be found in Italy, where a depiction of a candlestick exists in an [[Etruscan civilization|Etruscan]] tomb at [[Orvieto]],{{sfn|Forbes|1966|page=[https://books.google.com/books?id=N6Y3AAAAIAAJ&pg=PA140 140] }} and the earliest excavated Etruscan candlestick dates from the 7th century BC.{{sfn|Baur|1996|page=18}} Candles may have evolved from [[wikt:taper#English:_candle|taper]] with wick of [[oakum]] and other plant fibre soaked in fat, pitch or oil and burned in lamps or pots.{{sfn|Forbes|1966|page=[https://books.google.com/books?id=-VmmHdm5STIC&pg=PA134 134] }} Candles of antiquity were made from various forms of natural fat, tallow, and wax, and [[Ancient Rome|Romans]] made true dipped candles from [[tallow]] and beeswax.<ref>{{cite web |url=http://www.smith.edu/hsc/museum/ancient_inventions/candles2.html |title=Candles, Roman, 500 BCE |website=Smith College Museum}}</ref> Beeswax candles were expensive and their use was limited to the wealthy, so oil lamps were the more commonly used lighting devices in Roman times. [[Ancient Greece]] used torches and oil lamps, and likely adopted candle use in a later period from Rome.{{sfn|Forbes|1966|page=[https://books.google.com/books?id=N6Y3AAAAIAAJ&pg=PA140 140] }} Early record in China suggests that candles were used in the [[Qin dynasty]] before 200&nbsp;BC. These early Chinese candles may have been made from whale fat.<ref>{{Cite web |date=6 December 2020 |title=The Best Candle Pouring Pots for Learning an Ancient Craft|url=https://www.artnews.com/art-news/product-recommendations/best-candle-pouring-pots-1234577128/ |access-date=2023-02-02 |website=Art News}}</ref>

[[File:Феофил III.jpg|thumb|upright|left|Candles used in the [[Church of the Holy Sepulchre]] in [[Jerusalem]]]]

In Christianity, candles gained significance in their decorative, symbolic and [[Ceremonial use of lights#Christianity|ceremonial uses]] in churches. Wax candles, or ''candela cerea'' recorded at the end of the 3rd century, were documented as [[Easter candle]]s in Spain and Italy in the fourth century,{{sfn|Baur|1996|page=7}} the Christian festival [[Candlemas]] was named after it, and [[Pope Sergius I]] instituted the procession of lighted candles. [[Papal bull]]s decreed that tallow be excluded for use in altar candles, and a high beeswax content is necessary for candles of the high altar.{{sfn|Forbes|1966|page=[https://books.google.com/books?id=N6Y3AAAAIAAJ&pg=PA141 141] }}

In medieval Europe, candles were initially used primarily in Christian churches. Their use spread later to the households of the wealthy as a luxury item.{{sfn|Baur|1996|page=8&ndash;9}}  In Northern Europe, especially England, [[rushlight|rushlights]] made of greased rushes were commonly used, but [[tallow]] candles were used during the Middle Ages, with a mention of tallow candles in English appearing in 1154.{{sfn|Baur|1996|pages=7&ndash;8}} [[Beeswax]] was widely used in church ceremonies. Compared to animal-based tallow, it burns cleanly without smoky flame, and does not release an unpleasant smell like tallow. Beeswax candles were expensive, and relatively few people could afford to burn them in their homes in medieval Europe.<ref>{{cite web|title=history of candle|url=http://candles.org/history/|work=national candle association}}</ref>

[[File:Osterkerze Ostervigil 2023.jpg|thumb|upright|A [[Paschal candle]] being carried]]
The candles were produced using a number of methods: dipping the wick in molten fat or wax, rolling the candle by hand around a wick, or pouring fat or wax onto a wick to build up the candle. In the 14th century Sieur de Brez introduced the technique of using a mould, but real improvement for the efficient production of candles with mould was only achieved in the 19th century.{{sfn|Forbes|1966|page=[https://books.google.com/books?id=N6Y3AAAAIAAJ&pg=PA139 138–139] }} Wax and tallow candles were made in monasteries in the medieval period, and in rural households, tallow candles were made at home.{{sfn|Baur|1996|page=8}}  By the 13th century, candle making had become a guild craft in England and France, with a French guild documented as early as 1061.{{sfn|Baur|1996|page=8}} The candle makers (chandlers) went from house to house making candles from the kitchen fats saved for that purpose, or made and sold their own candles from small candle shops.<ref>{{cite web|url=http://www.candles.org/about_history.html |title=History of candles |publisher=National Candle Association |access-date=2012-05-19 |url-status=dead |archive-url=https://web.archive.org/web/20120517112023/http://www.candles.org/about_history.html |archive-date=May 17, 2012 }}</ref>

By the 16th century, beeswax candles were appearing as luxury household items among the wealthy.{{sfn|Baur|1996|page=9}} Candles were widely used in the 17th and 18th centuries, and a party in [[Dresden]] was said to have been lit by 14,000 candles in 1779.{{sfn|Baur|1996|page=9}}

In the Middle East, during the [[Abbasid]] and [[Fatimid]] Caliphates, beeswax was the dominant material used for candle making.{{sfn|Beg|1997|page=288}} Beeswax was often imported from long distances; for example, candle makers from Egypt used beeswax from [[Tunis]].{{sfn|Beg|1997|page=288}} As in Europe, these candles were expensive and limited to the elite, and most commoners used oil lamps instead.{{sfn|Beg|1997|page=288}} According to legend, the practice of using lamps and candles in mosque started with [[Tamim al-Dari]] who lit a lamp he brought from Syria in the [[Prophet's Mosque]] in Medina. The [[Umayyad Caliphate|Umayyad]] caliph [[Al-Walid II]] was known to have used candles in the court in Damascus, while the Abbasid caliph [[al-Mutawakkil]] was said to have spent 1.2&nbsp;million silver [[dirham]]s annually on candles for his royal palaces.{{sfn|Beg|1997|page=288}}

In early modern Syria, candles were in high demand by all socioeconomic classes because they were customarily lit during marriage ceremonies.{{sfn|Beg|1997|page=288}} There were candle makers' guilds in the [[Safavid]] capital of [[Isfahan]] during the 1500s and 1600s.{{sfn|Beg|1997|page=288}} However, candle makers had a relatively low social position in Safavid Iran, comparable to [[barber]]s, [[hammam|bathhouse]] workers, fortune tellers, bricklayers, and [[porter (carrier)|porter]]s.{{sfn|Beg|1997|page=288}}

In the 18th and 19th centuries, [[spermaceti]], a waxy substance produced by the [[sperm whale]], was used to produce a superior candle that burned longer, brighter and gave off no offensive smell.<ref>{{cite book | last = Shillito | first = M. Larry   |author2=David J. De Marle | title = Value: Its Measurement, Design, and Management | publisher = Wiley-IEEE | year = 1992 | page = 33 | url = https://books.google.com/books?id=e01LfamiCpUC&q=Spermaceti+candle+18th+century&pg=PA33 | isbn = 978-0-471-52738-1}}</ref> Later in the 18th century, [[colza oil]] and [[rapeseed]] oil came into use as much cheaper substitutes.

===Modern era===
[[File:Price's Palmitine Candles00.jpg|thumb|upright|[[Price's Candles]] had become the largest candle manufacturer in the world by the end of the 19th century]]

A number of improvements were made to the candle in the 19th century. In older candles, the wick of a burning candle was not in direct contact with air, so it charred instead of being burnt. The charred wick inhibited further burning and produced black smoke, so the wick needed to be constantly trimmed or "snuffed".{{sfn|LeFever|2007|page=65}} In 1825, a French man M. Cambacérès introduced the plaited wick soaked with mineral salts, which when burnt, curled towards the outer edge of the flame and become incinerated by it, thereby trimming itself.{{sfn|Forbes|1966|page=[https://books.google.com/books?id=-VmmHdm5STIC&pg=PA134 134] }} These are referred to as "self-trimming" or "self-consuming" wicks.<ref>{{Cite web |url=http://www.expressivecandles.com/history.php |title=A Brief History of Candles |access-date=2015-07-06 |archive-url=https://web.archive.org/web/20130318072713/http://www.expressivecandles.com/history.php |archive-date=2013-03-18 |url-status=dead }}</ref> In 1823, [[Michel Eugène Chevreul]] and [[Joseph Louis Gay-Lussac]] separate out [[stearin]] in animal fats, and obtained a patent in 1825 to produce candles that are harder and can burn brighter.{{sfn|Forbes|1966|page=[https://books.google.com/books?id=N6Y3AAAAIAAJ&pg=PA139 138–139] }}{{sfn|LeFever|2007|page=65}}

The manufacture of candles became an industrialized mass market in the mid 19th century. In 1834, Joseph Morgan,<ref>{{cite web|url=http://www.gracesguide.co.uk/Joseph_Morgan_and_Son|title=Joseph Morgan and Son |work=Graces Guide}}</ref> a [[pewter]]er from [[Manchester]], England, patented a machine that revolutionised candle making. It allowed for continuous production of molded candles by using a cylinder with a moveable piston to eject candles as they solidified. This more efficient mechanized production produced about 1,500&nbsp;candles per hour. This allowed candles to be an affordable commodity for the masses.<ref>{{cite book | last = Phillips | first = Gordon  | title = Seven Centuries of Light: The Tallow Chandlers Company | publisher = Book Production Consultants  | year = 1999 | url = https://books.google.com/books?id=OWt03_on0qUC&q=Joseph+Morgan+candles+1834&pg=PA74 | isbn = 978-1-85757-064-9 | page = 74}}</ref>

In the mid-1850s, [[James Young (Scottish chemist)|James Young]] succeeded in distilling [[paraffin wax]] from coal and oil shales at [[Bathgate]] in [[West Lothian]] and developed a commercially viable method of production.<ref>{{cite book | last = Golan | first = Tal  | title = Laws of Men and Laws of Nature: The History of Scientific Expert Testimony in England and America | publisher = Harvard University Press | year = 2004 | pages = 89–91 | url = https://books.google.com/books?id=kQhYsAmcj-EC&q=james+young+patent+paraffin&pg=PA90  | isbn = 978-0674012868}}</ref> Paraffin could be used to make inexpensive candles of high quality. It was a bluish-white wax, which burned cleanly and left no unpleasant odor, unlike [[tallow]] candles. By the end of the 19th century, candles were made from paraffin wax and [[stearic acid]].

By the late 19th century, [[Price's Candles]], based in London, was the largest candle manufacturer in the world.<ref>{{cite book|url=https://books.google.com/books?id=fJo7AwAAQBAJ|title=London's Industrial Heritage|author=Geoff Marshall|year=2013|publisher=The History Press|isbn=9780752492391}}</ref> Founded by William Wilson in 1830,<ref>{{cite book | last = Ball  | first = Michael  |author2=David Sunderland | title = An Economic History of London, 1800-1914 | publisher = Routledge | year = 2001 | pages = 131–132 | url = https://books.google.com/books?id=MI6JfTiEcdAC&q=Prices+Candles+Coconut&pg=PA132 | isbn = 978-0415246910}}</ref> the company pioneered the implementation of the technique of [[steam distillation]], and was thus able to manufacture candles from a wide range of raw materials, including skin fat, bone fat, fish oil and industrial greases.

Despite advances in candle making, the candle industry declined rapidly upon the introduction of superior methods of lighting, including [[kerosene lamp]]s and the 1879 invention of the [[incandescent light bulb]]. From this point on, candles came to be marketed as more of a decorative item.<ref>{{Cite journal|last1=Sekimoto|first1=Hiroshi|last2=Ryu|first2=Kouichi|last3=Yoshimura|first3=Yoshikane|date=2001-11-01|title=CANDLE: The New Burnup Strategy|url=https://doi.org/10.13182/NSE01-01|journal=Nuclear Science and Engineering|volume=139|issue=3|pages=306–317|doi=10.13182/NSE01-01|bibcode=2001NSE...139..306S |s2cid=121714669|issn=0029-5639|url-access=subscription}}</ref>

==Use==
{{See also|Ceremonial use of lights}}
[[File:Kosovo-metohija-koreni-duse027.jpg|thumb|Candle lighting in the [[Visoki Dečani]] monastery]]

Before the invention of [[electric light]]ing, candles and oil lamps were commonly used for illumination. In areas without electricity, they are still used routinely. In the developed world today, candles are used mainly for their aesthetic value and scent, particularly to set a soft, warm, or romantic ambiance, or for emergency lighting during electrical [[power failure]]s.<ref name="guardian_candle">{{cite web |last1=Ferrier |first1=Morwenna |title=The cult of 'smellness': what's behind the extraordinary rise in sales of scented candles? |url=https://www.theguardian.com/fashion/2018/dec/19/the-cult-of-smellness-whats-behind-the-extraordinary-rise-in-sales-of-scented-candles |website=The Guardian |date=19 December 2018 |publisher=Guardian News & Media Limited |access-date=4 February 2021}}</ref> They are also still commonly used in religious and ceremonial contexts. Examples include [[votive candle]]s, [[Paschal candle]]s and [[yahrzeit candle]]s. In the days leading to Christmas, some people burn a candle a set amount to represent each day, as marked on the candle. The type of candle used in this way is called the ''[[Advent candle]]'',<ref>{{cite book | last = Geddes | first = Gordon  |author2=Jane Griffiths | title = Christianity | publisher = Heinemann | page = 89 | url = https://books.google.com/books?id=Wn-38NunUnAC&q=advent+candle&pg=PT98 | isbn = 978-0-435-30693-9| year = 2002  }}</ref> although this term is also used to refer to candles that are used in an [[Advent wreath]].
[[File:CandlesInBuddhistTemple.JPG|thumb|left|Candles in a Buddhist temple]]

Symbolic use of candles has extended from the religious to the secular, for example, a [[candlelight vigil]] may be held in remembrance for a person, for a cause or an event, or as a form of political action or protest.<ref>{{cite web |url=https://endly.co/what-is-a-candlelight-vigil-definition-types/|title=What Is a Candlelight Vigil: Meaning, Types & Symbolism|date=August 2, 2023|work=Endly }}</ref> In a social setting, candles are commonly used on [[birthday cake]]s.

In the 21st century, there has been an increase in sales of scented candles in recent years,<ref name="guardian_candle" /> particularly during the [[COVID-19 pandemic]] and the ensuing [[Lockdowns related to COVID-19|lockdowns]], with scented candles, diffusers and room sprays becoming popular.<ref name="wwd_candle">{{cite web |last1=Thomas |first1=Ellen |title=Candles Burn Bright Amid Coronavirus Pandemic |url=https://wwd.com/beauty-industry-news/beauty-features/candles-burn-bright-amid-coronavirus-pandemic-1203556807/ |website=WWD |date=10 April 2020 |access-date=24 May 2021 |ref=wwd_candle}}</ref><ref name="guardian_candle2">{{cite web |last1=Wood |first1=Zoe |title=UK sales of scented candles soar as Covid restrictions tighten |url=https://www.theguardian.com/business/2020/nov/10/uk-sales-scented-candles-covid-restrictions-kantar |website=The Guardian |date=10 November 2020 |publisher=The Guardian News & Media Limited |access-date=4 February 2021}}</ref>

===Other uses===
[[File:KerzenuhrEdited.jpg|thumb|upright|A type of [[candle clock]]]]
With the fairly consistent and measurable burning of a candle, a common use of candles was to tell the [[candle clock|time]]. The candle designed for this purpose might have time measurements, usually in hours, marked along the wax. The [[Song dynasty]] in China (960–1279) used [[candle clock]]s.<ref>{{cite book|last=Whitrow |first=G. J. |title=Time in History: Views of Time from Prehistory to the Present Day |publisher=Oxford University Press |year=1989 |pages=90–91 |url=https://books.google.com/books?id=o8Nb5KLBxVQC&q=Sung+dynasty+incense+clocks&pg=PA91 |isbn=978-0-19-285211-3 |url-status=dead |archive-url=https://web.archive.org/web/20150610204616/https://books.google.com/books?id=o8Nb5KLBxVQC&pg=PA91&dq=Sung+dynasty+incense+clocks |archive-date=June 10, 2015 }}</ref>

By the 18th century, candle clocks were being made with weights set into the sides of the candle. As the candle melted, the weights fell off and made a noise as they fell into a bowl.

==Components==

===Wax===
[[File:7candles.JPG|thumb|upright|left|Unlit twisted beeswax candles]]

For most of recorded history candles were made from [[tallow]] (rendered from beef or mutton-fat) or [[beeswax]]. From the mid-1800s, they were also made from [[spermaceti]], a waxy substance derived from the [[Sperm whale]], which in turn spurred demand for the substance. Candles were also made from [[stearin]] (initially manufactured from animal fats but now produced almost exclusively from palm waxes).<ref>{{cite web|title=Using stearic acid or stearin in candlemaking|url=http://www.happynews.com/living/create/using-stearic-acid.htm|website=happynews.com|access-date=25 September 2014|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304000000/http://www.happynews.com/living/create/using-stearic-acid.htm|url-status=dead}}</ref><ref>{{cite web|title=Stearic acid (stearin)|url=http://www.howtomakecandles.info/cm_article.asp?ID=ADDIT0003|website=howtomakecandles.info|access-date=25 September 2014}}</ref> Today, most candles are made from [[paraffin wax]], a byproduct of [[petroleum]] refining.<ref name= Ullmann>Franz Willhöft and Fredrick Horn "Candles" in Ullmann's Encyclopedia of Industrial Chemistry, 2000, Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a05_029}}</ref>

[[File:Hentriacontane.svg|thumb|The hydrocarbon [[Hentriacontane|C<sub>31</sub>H<sub>64</sub>]] is a typical component of paraffin wax, from which most modern candles are produced.]]
Candles can also be made from [[microcrystalline wax]], [[beeswax]] (a byproduct of [[honey collection]]), [[gel]] (a mixture of [[polymer]] and [[mineral oil]]),<ref>{{cite journal|last1=Camp|first1=William R.|last2=Vollenweider |first2=Jeffrey L. |last3=Schutz |first3= Wendy J. |title=Scented candle gel|journal=United States Patent 5,964,905|date=12 October 1999}}</ref> or some [[Wax#Plant waxes|plant waxes]] (generally palm, [[carnauba wax|carnauba]], [[bayberry]], or [[soybean wax]]). In the Far East, [[stillingia tallow]] and [[Japan wax]] from plants have been used for centuries. They also used [[Chinese wax]] produced from insects.

The size of the flame and corresponding rate of burning is controlled largely by the [[candle wick]]. The kind of wax also affects the burn rate, with beeswax and coconut wax burning longer than paraffin or soy wax.<ref>{{cite web|title=Candle Wax Guide: Comparing Soy, Paraffin, Coconut, and Beeswax|url=https://valiantcandle.com/post/1030204903881/candle-wax-guide-comparing-soy-paraffin|website=valiantcandle.com|access-date=24 February 2021}}</ref>

Production methods utilize [[extrusion moulding]].<ref name= Ullmann/> More traditional production methods entail [[melting]] the solid fuel by the controlled application of heat. The liquid is then poured into a mould, or a wick is repeatedly immersed in the liquid to create a dipped tapered candle. Often [[fragrance oil]]s, [[essential oil]]s or [[aniline]]-based [[dye]] is added.

===Wick===
{{main|Candle wick}}
[[File:Candle Wick.jpg|thumb|upright|Candle with unlit wick]]

A candle wick works by [[capillary action]], drawing ("wicking") the melted wax or [[fuel]] up to the flame. When the liquid fuel reaches the flame, it [[vaporize]]s and [[Combustion|combusts]]. The candle wick influences how the candle burns. Important characteristics of the wick include diameter, stiffness, [[Fireproofing|fire resistance]], and tethering.

A candle wick is a piece of string or cord that holds the flame of a candle. Commercial wicks are made from braided cotton. The wick's [[capillary action|capillarity]] determines the rate at which the melted hydrocarbon is conveyed to the flame. If the capillarity is too great, the molten wax streams down the side of the candle. Wicks are often infused with a variety of [[chemical]]s to modify their burning characteristics. For example, it is usually desirable that the wick not glow after the flame is extinguished. Typical agents are [[ammonium nitrate]] and [[ammonium sulfate]].<ref name= Ullmann/>

==Characteristics==
{{more citations needed section|date=January 2021}}

===Light===
[[File:candles.jpg|thumb|A room lit by the glow of many candles]]

Based on measurements of a taper-type, paraffin wax candle, a modern candle typically burns at a steady rate of about 0.1&nbsp;g/min, releasing heat at roughly 80&nbsp;W.<ref name=Hamins>{{cite journal |last1=Hamins |first1=Anthony |last2=Bundy |first2=Matthew |last3=Dillon |first3=Scott E. |date=November 2005 |title=Characterization of Candle Flames |journal=Journal of Fire Protection Engineering |volume=15 |issue= 4|page=277 |doi=10.1177/1042391505053163 |url=https://ws680.nist.gov/publication/get_pdf.cfm?pub_id=101159  |format=PDF|citeseerx=10.1.1.548.3798 }}</ref> The light produced is about 13&nbsp;[[lumen (unit)|lumens]], for a [[luminous efficacy]] of about 0.16&nbsp;lumens per watt (luminous efficacy of a source)&nbsp;– almost a hundred times lower than an [[incandescent light bulb]]. If a 1&nbsp;[[candela]] source emitted uniformly in all directions, the total [[radiant flux]] would be only about 18.40&nbsp;mW.

The [[luminous intensity]] of a typical candle is approximately one [[candela]]. The [[SI]] unit, candela, was in fact based on an older unit called the ''[[candlepower]]'', which represented the luminous intensity emitted by a candle made to particular specifications (a "standard candle"). The modern unit is defined in a more precise and repeatable way, but was chosen such that a candle's luminous intensity is still about one candela.

===Temperature===
{{see also|Combustion}}

The hottest part of a candle flame is just above the very dull blue part to one side of the flame, at the base. At this point, the flame is about {{convert|1400|C|F}}. However, this part of the flame is very small and releases little heat energy. The blue color is due to [[chemiluminescence]], while the visible yellow color is due to radiative emission from hot [[soot]] particles. The soot is formed through a series of complex chemical reactions, leading from the fuel molecule through molecular growth, until multi-carbon ring compounds are formed. The thermal structure of a flame is complex, hundreds of degrees over very short distances leading to extremely steep temperature gradients. On average, the flame temperature is about {{convert|1000|C|F|-2}}.<ref>{{cite web|url=http://www.pbslearningmedia.org/resource/phy03.sci.phys.matter.onfire/on-fire/|title=On Fire – Background Essay|website=PBS LearningMedia|publisher=[[PBS]] and [[WGBH Educational Foundation]]|access-date=April 8, 2015|archive-date=April 3, 2015|archive-url=https://web.archive.org/web/20150403065509/http://www.pbslearningmedia.org/resource/phy03.sci.phys.matter.onfire/on-fire/|url-status=dead}}</ref> The [[color temperature]] is approximately 1,000&nbsp;K.

===Combustion===

For a candle to burn, a heat source (commonly a naked flame from a [[match]] or [[lighter]]) is used to light the candle's wick, which melts and [[vaporizes]] a small amount of fuel (the wax). Once vaporized, the fuel combines with [[oxygen]] in the atmosphere to ignite and form a constant [[flame]]. This flame provides sufficient heat to keep the candle burning via a self-sustaining chain of events: the heat of the flame melts the top of the mass of solid fuel; the liquefied fuel then moves upward through the wick via [[capillary action]]; the liquefied fuel finally vaporizes to burn within the candle's flame.

As the fuel (wax) is melted and burned, the candle becomes shorter. The end of the plaited wick bends and get consumed in the flame. The incineration of the wick limits the length of the exposed portion of the wick, thus maintaining a constant burning temperature and rate of fuel consumption. Pre-19th century wicks required regular trimming with scissors (or a specialized wick trimmer), usually to about one-quarter inch (~0.7&nbsp;cm), to promote steady burning and to prevent it from releasing black smoke. Special candle scissors called "[[Candle snuffer|snuffers]]" were produced for this purpose in the 20th century and were often combined with an extinguisher. In modern candles, the wick is made in such a way that it curves over as it burns, which ensures that the end of the wick gets incinerated by [[fire]], thereby trimming itself.<ref name=candles />

===Candle flame===
[[File:Anatomy of a candle flame.svg|thumb|Five zones of a standard domestic candle flame]]

A candle flame is formed because wax vaporizes on burning. A candle flame is widely recognized as having between three and five regions or "zones":
* Zone I – this is the non-luminous, lowest, and coolest part of the candle flame. It is located around the base of the wick where there is insufficient oxygen for fuel to burn. Temperatures are around {{convert|600|C|F}}.
* Zone II – this is the ''blue zone'', which surrounds the base of the flame. Here the supply of oxygen is plentiful, and the fuel burns clean and blue. It is heat from this zone which causes the wax to melt. Temperatures are around {{convert|800|C|F}}.
* Zone III – the ''dark zone'' is a region directly above the wick containing unburnt wax. [[Pyrolysis]] takes place here. Temperature is around {{convert|1000|C|F}}.
*Zone IV – the ''middle'' or ''luminous zone'' is yellow/white and is located above the dark zone. It is the brightest zone, but not the hottest. It is an oxygen-depleted zone with insufficient oxygen to burn all of the wax vapor rising from below it, resulting in only partial combustion. The zone also contains unburnt carbon particles. Temperature is around {{convert|1200|C|F}}.
* Zone V – The non-luminous ''outer zone'' or ''veil'' surrounds Zone IV. Here, the flame is at its hottest, at around {{convert|1400|C|F}}, and complete combustion occurs. It is light blue in color, though most of it is invisible.<ref>{{cite journal|journal=Ohio State University|title=FTIR Study of Combustion Species In Several Regions of a Candle Flame|author=Allen R. White|date=2013|hdl=1811/55436}}</ref><ref>[[National Council of Educational Research and Training]]. "Science: Textbook for Class VIII". Publication Department, 2010, p. 72.</ref>

The main determinant of the height of a candle flame is the diameter of the wick. This is evidenced in [[tealight]]s where the wick is very thin and the flame is very small. Candles whose main purpose is illumination use a much thicker wick.<ref>{{cite journal |last1=Sunderland |first1=P.B. |last2=Quintiere |first2=J.G. |last3=Tabaka |first3=G.A. |last4=Lian |first4=D. |last5=Chiu |first5=C.-W. |title=Analysis and measurement of candle flame shapes |url=http://terpconnect.umd.edu/~pbs/2011-Sunderland-et-al-PCI.pdf |date=6 October 2010 |journal=Proceedings of the Combustion Institute |volume=33 |issue=2 |pages=2489–2496 |doi=10.1016/j.proci.2010.06.095 |access-date=2015-02-10 |archive-url=https://web.archive.org/web/20160304090022/http://terpconnect.umd.edu/~pbs/2011-Sunderland-et-al-PCI.pdf |archive-date=4 March 2016 |url-status=dead }}</ref>

===History of study===
One of [[Michael Faraday]]'s significant works was ''[[The Chemical History of a Candle]]'', where he gives an in-depth analysis of the evolutionary development, workings and science of candles.<ref>{{cite web |url=http://www.fordham.edu/halsall/mod/1860Faraday-candle.asp |title=Internet History Sourcebooks |publisher=Fordham.edu |access-date=2012-12-25}}</ref>

==Hazards==
According to the [[National Fire Protection Association]], candles are a leading source of residential fires in the United States with almost 10% of civilian injuries and 6% of fatalities from fire attributed to candles.<ref>John Hall, NFPA 2009,  {{cite web|url=http://www.nfpa.org/assets/files/ |title=Archived copy |access-date=2013-01-27 |url-status=dead |archive-url=https://web.archive.org/web/20110727124011/http://www.nfpa.org/assets/files//PDF/Research/Fire_overview_2009.pdf |archive-date=2011-07-27 }}.</ref>

A candle flame that is longer than its laminar smoke point will emit [[soot]].<ref>K.M. Allan, J.R. Kaminski, J.C. Bertrand, J. Head, [[Peter B. Sunderland]], Laminar Smoke Points of Wax Candles, Combustion Science and Technology 181 (2009) 800–811.</ref> Proper wick trimming will reduce soot emissions from most candles.

The liquid wax is hot and can cause skin burns, but the amount and temperature are generally rather limited and the burns are seldom serious. The best way to avoid getting burned from splashed wax is to use a [[candle snuffer]] instead of blowing directly on the flame. A candle snuffer is usually a small metal cup on the end of a long handle. Placing the snuffer over the flame cuts off the oxygen supply. Snuffers were common in the home when candles were the main source of lighting before electric lights were available. Ornate snuffers, often combined with a taper for lighting, are still found in those churches which regularly use large candles.

Glass candleholders are sometimes cracked by thermal shock from the candle flame, particularly when the candle burns down to the end. When burning candles in glass holders or jars, users should avoid lighting candles with chipped or cracked containers and discontinue use once a half inch or less of wax remains.

A former worry regarding the safety of candles was that a [[lead]] core was used in the wicks to keep them upright in container candles. Without a stiff core, the wicks of a container candle could sag and drown in the deep wax pool. Concerns rose that the lead in these wicks would vaporize during the burning process, releasing lead vapors&nbsp;– a known health and developmental hazard. Lead core wicks have not been common since the 1970s. Today, most metal-cored wicks use [[zinc]] or a zinc [[alloy]], which has become the industry standard. Wicks made from specially treated paper and cotton are also available.

Candles emit [[volatile organic compound]]s into the environment, which releases carbon into the air.<ref>{{Cite web |date=2021-04-08 |title=10 Eco-Friendly Sustainable Candles For A Clean Burn - The Eco Hub |url=https://theecohub.com/eco-friendly-sustainable-candles/ |access-date=2022-11-07 |website=theecohub.com |language=en-US}}</ref> The combustion process of lighting a candle includes the release of light, heat, carbon dioxide and water vapor, to fuel the flame.<ref>{{Cite web |title=Candles: What do they emit when lit? |url=https://www.mcgill.ca/oss/article/student-contributors-you-asked-general-science/candles-what-do-they-emit-when-lit |access-date=2022-11-13 |website=Office for Science and Society |language=en}}</ref> Candle use can be unsafe if fragrances are inhaled at high doses<ref name="womenshealthmag.com">{{Cite web |date=2022-09-27 |title=You Need To Follow These Expert Tips To Make Sure You're Using Your Scented Candles Safely |url=https://www.womenshealthmag.com/health/a41352744/are-candles-bad-for-you/ |access-date=2022-11-13 |website=Women's Health |language=en-us}}</ref><ref name="theecohub.com">{{Cite web |date=2021-04-08 |title=10 Eco-Friendly Sustainable Candles For A Clean Burn - The Eco Hub |url=https://theecohub.com/eco-friendly-sustainable-candles/ |access-date=2022-11-13 |website=theecohub.com |language=en-US}}</ref> Non-toxic candles have been created as an alternative to prevent these volatile organic compounds from being released into the environment.<ref name="vogue.co.uk">{{Cite web |date=2020-05-12 |title=The Ultimate Guide To Non-Toxic Candles |url=https://www.vogue.co.uk/beauty/article/sustainable-candles |access-date=2022-11-13 |website=British Vogue |language=en-GB}}</ref> Candle companies such as "The Plant Project" have created candles that are more environmentally sustainable and better for lung health.<ref name="theecohub.com"/> These alternatives include non-toxic wax blends, safe fragrances and eco-friendly packaging.<ref name="vogue.co.uk"/> Safer candles include candles made from coconut, soy, vegetable, and beeswax.<ref name="womenshealthmag.com"/>

Users who seek the aesthetics of a candle sometimes install an electric [[flameless candle]] to avoid the hazards.

==Regulation==
International markets have developed a range of standards and [[regulation]]s to ensure compliance, while maintaining and improving [[safety]], including:
* Europe: GPSD, EN 15493, EN 15494, EN 15426, EN 14059, [[Registration, Evaluation, Authorisation and Restriction of Chemicals|REACH]], RAL-GZ 041 Candles (Germany), French Decree 91-1175
* United States: ASTM F2058, ASTM F2179, ASTM F2417, ASTM F2601, ASTM F2326 (all are federal and applies in all 50 states), [[California Proposition 65 (1986)|California Proposition 65]] ([[California]] only), [[CONEG]] ([[New England]] and [[New York (state)|New York]] states only)
* China: QB/T 2119 Basic Candle, QB/T 2902 Art Candle, QB/T 2903 Jar Candle, GB/T 22256 Jelly Candle

==Accessories==
{{more citations needed section|date=January 2021}}

===Candle holders===
[[File:Pair of Girandoles - Getty collection 85.DF.382.jpg|thumb|upright|left|A type of decorative candelabra called [[girandole]], late 17th century]]
Decorative candleholders, especially those shaped as a pedestal, are called [[candlestick]]s; if multiple candle tapers are held, the term ''[[candelabra]]'' is also used. The root form of ''[[chandelier]]'' is from the word for candle, but now often refers to an electric fixture. The word ''chandelier'' is used to describe a hanging fixture designed to hold multiple lights. Other forms of candle holders include the wall-mounted [[Sconce (light fixture)|sconces]], [[lantern]]s, and [[girandole]]s.<ref name=banham>{{cite book |url=https://books.google.com/books?id=MlKhCAAAQBAJ&pg=PA225 |title=Encyclopedia of Interior Design|date=1997 |publisher=Taylor & Francis |isbn=9781136787584 |editor=Joanna Banham |pages=225&ndash;226 }}</ref>

[[File:Candle holder, French, circa 1830-1850, patinated and gilt bronze, inherited from Maurice Quentin Bauchart, 1911, inv. 17782 A, Museum of Decorative Arts, Paris.jpg|thumb|upright|A candle holder, 19th century]]
Many candle holders use a friction-tight socket to keep the candle upright. In this case, a candle that is slightly too wide will not fit in the holder, and a candle that is slightly too narrow will wobble. Candles that are too big can be trimmed to fit with a knife; candles that are too small can be fitted with aluminium foil. Traditionally, the candle and candle holders were made in the same place, so they were appropriately sized, but [[common market|international trade]] has combined the modern candle with existing holders, which makes the ill-fitting candle more common. This friction-tight socket is only needed for the federals{{clarify|date=October 2022}} and the tapers. 

For [[tea light]] candles, there is a variety of candle holders, including small glass holders and elaborate multi-candle stands. The same is true for [[votive candle|votives]]. Wall sconces are available for tea light and votive candles. For pillar-type candles, the assortment of candle holders is broad. A fireproof plate, such as a glass plate or small mirror, can be a candle holder for a pillar-style candle. A pedestal of any kind, with the appropriate-sized fireproof top, is another option. A large glass bowl with a large flat bottom and tall mostly vertical curved sides is called a hurricane. The pillar-style candle is placed at the bottom center of the hurricane. A hurricane on a pedestal is sometimes sold as a unit.

A [[bobèche]] is a drip-catching ring, which may also be affixed to a candle holder, or used independently of one. Bobèches can range from ornate metal or glass to simple plastic, cardboard, or wax paper. Use of paper or plastic bobèches is common at events where candles are distributed to a crowd or audience, such as Christmas carolers or people at other concerts or festivals.

[[File:Zilveren miniatuur kaarsensnuiter, objectnr 1016.JPG|thumb|Wick-trimmer]]

===Candle snuffers===
{{main|Candle snuffer}}
[[Image:Löschhütchen.jpg|thumb|A candle extinguisher]]
Candle snuffers are instruments used to extinguish burning candles by smothering the flame with a small metal cup that is suspended from a long handle, and thus depriving it of oxygen. An older meaning refers to a scissor-like tool used to trim the wick of a candle. With skill, this could be done without extinguishing the flame. The instrument now known as a candle snuffer was formerly called an "extinguisher" or "douter".

===Candle followers===
These are glass or metal tubes with an internal stricture partway along, which sit around the top of a lit candle. As the candle burns, the wax melts and the follower holds the melted wax in, whilst the stricture rests on the topmost solid portion of wax. Candle followers are often deliberately heavy or weighted to ensure they move down as the candle burns lower, maintaining a seal and preventing wax escape. The purpose of a candle follower is threefold:
* To contain the melted wax, making the candle more efficient, avoiding mess, and producing a more even burn.
* As a decoration, either due to the ornate nature of the device, or (in the case of a glass follower) through light dispersion or colouration.
* If necessary, to shield the flame from wind.

Candle followers are often found in churches on [[altar candle]]s.

==Gallery==
<gallery>
File:Tutankhamun tomb photographs 5 452.jpg|Object in the tomb of Tutankhamun
File:Washington National Cathedral (photo 2).jpg|Candlelight vigil
File:Sham' Gardani in Ardabil 2019-09-09 14.jpg|Candles used in Iran in a mourning ceremony
File:Sandakan Sabah SamSingKungTemple-22.jpg|Candles used in a Chinese temple
File:Cera (46362656605).jpg|Multi-wick candles used in a [[Festival of Saint Agatha (Catania)|Sicilian festival]]
File:Woman lighting the candles for the Festival of Lights in India (cropped).jpg|Lighting candles for the Indian festival of [[Diwali]]
File:Gamla Stan, Södermalm, Stockholm, Sweden - panoramio (231).jpg|A candelabra with candles in a Swedish cathedral
File:Kerzenpeng1.jpg|Handmade candles
File:RamirezLopezCandle02.JPG|A decorative candle in Mexico
File:Candle With Gold Stand.jpg|A small ornamental candle with a gold stand
</gallery>

==See also==
{{colbegin|colwidth=15em}}
* [[Candle-making]]
* [[Candle warmer]]
* [[Candelabra]]
* [[Eulachon]]
* [[Julleuchter]]
* [[Outdoor candle]]
* [[Rushlight]]
* [[Trick candles]]
* [[Trudon]]
* [[Unity candle]]
* [[Yahrzeit candle]]{{colend}}

==References==
{{Reflist}}

===Bibliography===
*{{cite book |url=https://books.google.com/books?id=PLGFAAAACAAJ |title=Metal Candlesticks: History, Styles and Techniques|first= Veronika |last=Baur |date= 1996|isbn=9780764301568 |publisher=Schiffer Publishing }}
*{{cite book |last1=Beg |first1=M.A.J. |url=https://ia600603.us.archive.org/14/items/EncyclopaediaDictionaryIslamMuslimWorldEtcGibbKramerScholars.13/09.EncycIslam.NewEdPrepNumLeadOrient.EdEdComCon.BosDonHeinLec.etc.UndPatIUA.v9.San-Sze.Leid.EJBrill.1997..pdf |title=The Encyclopaedia of Islam, Vol. IX (SAN-SZE) |date=1997 |publisher=Brill |isbn=90-04-10422-4 |editor1-last=Bosworth |editor1-first=C.E. |location=Leiden |page=288 |chapter=SHAMMĀ' |access-date=13 June 2022 |editor2-last=van Donzel |editor2-first=E. |editor3-last=Heinrichs |editor3-first=W.P. |editor4-last=Lecomte |editor4-first=G. |archive-url=https://web.archive.org/web/20220325222100/https://ia600603.us.archive.org/14/items/EncyclopaediaDictionaryIslamMuslimWorldEtcGibbKramerScholars.13/09.EncycIslam.NewEdPrepNumLeadOrient.EdEdComCon.BosDonHeinLec.etc.UndPatIUA.v9.San-Sze.Leid.EJBrill.1997..pdf |archive-date=2022-03-25 |url-status=live}}
*{{cite book |url= https://books.google.com/books?id=-VmmHdm5STIC |title=Studies in Ancient Technology |first=Robert James |last=Forbes |publisher=Brill |date= 1966 |isbn=978-9004006263 }}
*{{cite magazine |url=https://www.gregorylefever.com/pdfs/Candlemaking2.pdf |title=Early Candle Making|first= Gregory |last=LeFever |date= 2007|magazine=Early American Life |pages=62–71 }}

==External links==
{{Wikiquote|Candles}}
{{CE1913 poster|Candles}}
* {{Commons category-inline|Candles}}
* [http://www.candles.org/ National Candle Association] of the [[United States|U.S.]]
* [https://www.gutenberg.org/ebooks/14474 The Chemical History of a Candle] by Michael Faraday
* [http://www.europecandles.org/ Association of European Candlemakers(AECM)] {{Webarchive|url=https://web.archive.org/web/20110704051510/http://www.europecandles.org/ |date=2011-07-04 }}
* [http://www.eca-candles.eu/ European Candle Association (ECA)]
* [http://www.alafave.org/ Latin American Candle Manufacturers Association (ALAFAVE)]
* [https://www.osmology.co/blog/candle-safety/ Guide To Candle Safety At Home - Osmology]

{{Artificial light sources}}

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[[Category:Candles| ]]