View source for Tricresyl phosphate

{{chembox
| ImageFile = Tricresyl_phosphate.png
| ImageSize = 250px
| IUPACName = 
| OtherNames = tricresylphosphate, tri-o-cresyl phosphate, TOCP, tritolyl phosphate, tolyl phosphate, tri-o-tolyl ester of phosphoric acid
| Section1 = {{Chembox Identifiers
| CASNo = 1330-78-5
| PubChem = 
| SMILES = O=P(Oc2ccccc2C)(Oc3ccccc3C)Oc1ccccc1C}}
| Section2 = {{Chembox Properties
| Formula = C<sub>21</sub>H<sub>21</sub>O<sub>4</sub>P
| MolarMass = 368.37 g/mole
| Appearance = 
| Density = 
| MeltingPt = -40 °C
| BoilingPt = 240-255 °C
| Solubility = }}
| Section3 = {{Chembox Hazards
| MainHazards = 
| FlashPt = > 225 °C
| Autoignition = }}
}}
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==Overview==
'''Tricresyl phosphate''', abbreviated TCP, is an [[organophosphate]] compound.  It is a derived from [[cresol]] and [[phosphoric acid]]. This viscous liquid is colourless when pure, but commercial samples are typically yellow. It is nonflammable and virtually insoluble in water.  Commercial tricresyl phosphate is a mixture of ortho, meta, and para-cresyl phosphates , the m- isomer is {{CASREF|CAS=563-04-2}}, the p- isomer is {{CASREF|CAS=78-32-0}}, and the o- isomer is {{CASREF|CAS=78-30-8}}.

==Production==
Tricresyl phosphate is manufactured by reaction of [[cresol]]s with [[phosphorus oxychloride]]:
:OPCl<sub>3</sub>  +  3 HOC<sub>6</sub>H<sub>4</sub>CH<sub>3</sub>   →  OP(OC<sub>6</sub>H<sub>4</sub>CH<sub>3</sub>)<sub>3</sub>  +  3 HCl
In alkaline medium it undergoes [[hydrolysis]] to cresol and dicresyl phosphate.
:OP(OC<sub>6</sub>H<sub>4</sub>CH<sub>3</sub>)<sub>3</sub>  +  NaOH  →    +  HOC<sub>6</sub>H<sub>4</sub>CH<sub>3</sub>  +  NaO<sub>2</sub>P(OC<sub>6</sub>H<sub>4</sub>CH<sub>3</sub>)<sub>2</sub>

== Uses ==
Tricresyl phosphate is used as a [[plasticizer]] in [[nitrocellulose]], [[acrylate]] [[lacquer]]s, [[varnish]]es, and in [[polyvinyl chloride]].  It is a [[flame retardant]] in [[plastic]]s and [[rubber]]s.  It is used as a [[gasoline additive]] as a lead scavenger for [[tetra-ethyl lead]].<ref>[http://www.pipercubforum.com/marvel.htm Marvel &amp; other solutions to the lead problem], checked 2009-06-18.</ref>  It is a [[hydraulic fluid]] and a [[coolant|heat exchange medium]].  Exploiting its hydrophobic properties, it is used in [[waterproofing]] of materials.  It is a [[solvent]] for [[solvent extraction|extraction]]s, a solvent for nitrocellulose and other polymers.  It is also used as an [[AW additive]] and [[EP additive]] in [[lubricant]]s, and in [[hydraulic fluid]]s.<ref>{{cite doi|10.1016/j.chroma.2007.05.087}}</ref> As a gasoline additive, it also helps preventing engine misfires.<ref name=Ullmann>Jürgen Svara1, Norbert Weferling2, Thomas Hofmann "Phosphorus Compounds, Organic" in Ullmann's Encyclopedia of Industrial Chemistry 2006, Wiley-VCH: Wienheim. DOI: 10.1002/14356007.a19_545.pub2. Article Online Posting Date: December 15, 2006</ref>

==Safety==
TCP is a known [[neurotoxin]]<ref>[http://toxsci.oxfordjournals.org/cgi/content/abstract/10/2/199 Lack of Delayed Neurotoxic Effect after Tri-o-cresyl Phosphate Treatment in Male Fischer 344 Rats: Biochemical, Neurobehavioral and Neuropathological Studies]</ref> and is of “toxicological importance” and has been responsible for many deaths. The most serious incident arose in the 1920s when TCP was used as an [[adulterant]] for [[Jamaican ginger]].<ref name=Ullmann/>
===Aircraft===
TCP is found in the engine oil of commercial jet [[airliners]]. It has been suggested that it can contaminate the cabin air through the engine [[bleed air]] system, and could therefore cause negative health effects in crew and passengers. Tests have found raised levels of TCP in some airline cabins, although the link between cabin TCP contamination and ill health, or conditions such as [[Jet lag]], has yet to be proved, although has been suggested.
<ref>[http://www.king5.com/health/stories/NW_022508HEB_cabin_air_SW.2a169305.html Do you know what you're breathing at 30,000 feet?], Date = 25-2-2008, Author = Chris Ingalls, Access date = 3-12-2008</ref>
<ref>[http://www.toxicfreeairlines.com The Toxic Free Airlines website], Date = unknown,  Author = unknown, Access date = 3-12-2008</ref>

==References==
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[[Category:Organophosphates]]
[[Category:Solvents]]
[[Category:Plasticizers]]
[[Category:Fuel additives]]
[[Category:Prohibition]]
[[Category:Neurotoxins]]

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