Tricresyl phosphate

Chembox new
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 = C₂₁H₂₁O₄P
MolarMass = 368.37 g/mole
Appearance =
Density =
MeltingPt = -40 °C
BoilingPt = 240-255 °C
Solubility =
Section3 = Chembox Hazards
MainHazards =
FlashPt = > 225 °C
Autoignition =

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 cresols with phosphorus oxychloride::OPCl₃ + 3 HOC₆H₄CH₃ → OP(OC₆H₄CH₃)₃ + 3 HClIn alkaline medium it undergoes hydrolysis to cresol and dicresyl phosphate.:OP(OC₆H₄CH₃)₃ + NaOH → + HOC₆H₄CH₃ + NaO₂P(OC₆H₄CH₃)₂

Uses

Tricresyl phosphate is used as a plasticizer in nitrocellulose, acrylate lacquers, varnishes, and in polyvinyl chloride. It is a flame retardant in plastics and rubbers. It is used as a gasoline additive as a lead scavenger for tetra-ethyl lead. It is a hydraulic fluid and a heat exchange medium. Exploiting its hydrophobic properties, it is used in waterproofing of materials. It is a solvent for extractions, a solvent for nitrocellulose and other polymers. It is also used as an AW additive and EP additive in lubricants, and in hydraulic fluids [ [http://dx.doi.org/10.1016/j.chroma.2007.05.087 Determination of airborne trialkyl and triaryl organophosphates originating from hydraulic fluids by gas chromatography–mass spectrometry Development of methodology for combined aerosol and vapor sampling] ] . As a gasoline additive, it also helps preventing engine misfires.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]

afety

TCP is a known neurotoxin [ [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] ] 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.

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. [ [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] [ [http://www.toxicfreeairlines.com The Toxic Free Airlines website] , Date = unknown, Author = unknown, Access date = 3-12-2008]

References