Xylene 118368 222998164 2008-07-02T02:53:45Z 69.235.154.148 /* Health effects */ {{see also|o-Xylene|m-Xylene|p-Xylene}} The term '''xylene''' or '''xylol''' refers to a mixture of three [[benzene]] derivatives which is used as a [[solvent]] in the [[printing]], [[rubber]], and [[leather]] industries. Xylene is a colorless, sweet-smelling liquid that is very flammable. Like other solvents, xylene is also used as an [[inhalant]] drug for its intoxicating properties. ==Chemical properties== '''Xylene''' is a generic term for a group of three [[benzene]] derivatives which encompasses ''ortho''-, ''meta''-, and ''para''- [[isomer]]s of [[dimethyl benzene]]. The ''o''-, ''m''- and ''p''- designations specify to which [[carbon]] atoms (of the [[benzene ring]]) the two [[methyl]] groups are attached. Counting the [[carbon]] [[atom]]s from one of the ring carbons bonded to a methyl group, and counting towards the second ring carbon bonded to a methyl group, the ''o''- isomer has the [[IUPAC]] name of 1,2-dimethylbenzene, the ''m''- isomer has the IUPAC name of 1,3-dimethylbenzene, and the ''p''- isomer has the IUPAC name of 1,4-dimethylbenzene. Solvent grade xylene usually contains a small percentage of [[ethylbenzene]] as a contaminent. [[Image:IUPAC-cyclic.svg|center|The xylene isomers]] The chemical properties differ slightly from isomer to isomer. The melting point is between {{convert|-47.87|°C|°F|2}} (''m''-xylene) and {{convert|13.26|°C|°F|2}} (''p''-xylene). The boiling point for each isomer is around {{convert|140|°C|°F|2}}. The density is at around 0.87 kg/L (7.26&nbsp;[[Pound (mass)|lb]]/U.S.&nbsp;gallon or 8.72&nbsp;lb/[[Imperial gallon|imp gallon]]) and thus is less dense than water. Xylene in air can be smelled at 0.08 to 3.7 parts of xylene per million parts of air (ppm) and can begin to be tasted in [[water]] at 0.53 to 1.8 ppm. ==Applications== Xylene is used as a [[solvent]] and in the [[printing]], [[rubber]], and [[leather]] industries. ''p''-Xylene is used as a feedstock in the production of [[terephthalic acid]], which is a [[monomer]] used in the production of [[polymer]]s. It is also used as a [[cleaning agent]] for [[steel]] and for [[silicon wafer]]s and [[integrated circuit|chip]]s, a [[pesticide]] [http://www.cdpr.ca.gov/cgi-bin/epa/chemdet.pl?pccode=086803], a [[paint thinner|thinner for paint]], and in [[paint]]s and [[varnish]]es. It may be substituted for [[toluene]] to thin lacquers where slower drying is desired. It is found in small amounts in [[jet fuel|airplane fuel]] and [[gasoline]]. In animal studies it is often swabbed on the ears of rabbits to facilitate blood flow and collection, although the area must subsequently be cleansed with alcohol to prevent inflammation. Xylene is also used as a fixation agent for animal tissues. <!-- Here is a table of data; skip past it to edit the text. --> {| align="center" border="1" cellspacing="0" cellpadding="3" style="margin: 0 0 0 0.5em; background: #FFFFFF; border-collapse: collapse; border-color: #C0C090;" ! {{chembox header}} align="center" colspan="5" | Xylene Isomers |- <!--| align="center" colspan="5" | [[Image:Xylene Isomers.PNG|400px|{{PAGENAME}}]] replace if not identical with the pagename --> |- ! {{chembox header}} align="center" colspan="5" | General |- | Common name | '''Xylenes''' | '''''o''-Xylene''' | '''''m''-Xylene''' | '''''p''-Xylene''' |- | [[IUPAC nomenclature|Systematic name]] | Dimethylbenzenes | 1,2-Dimethylbenzene | 1,3-Dimethylbenzene | 1,4-Dimethylbenzene |- | Other names | Xylols | ''o''-Xylol;<br>Orthoxylene | ''m''-Xylol;<br>Metaxylene | ''p''-Xylol;<br>Paraxylene |- | [[Chemical formula|Molecular formula]] | align="center" colspan="4" | C<sub>8</sub>H<sub>10</sub> (C<sub>6</sub>H<sub>4</sub>C<sub>2</sub>H<sub>6</sub>) |- | [[Simplified molecular input line entry specification|SMILES]] | | Cc1c(C)cccc1 | Cc1cc(C)ccc1 | Cc1ccc(C)cc1 |- | [[Molar mass]] | align="center" colspan="4" | 106.16 g/mol |- | Appearance | align="center" colspan="4" | clear, colorless liquid |- | [[CAS registry number|CAS number]] | [1330-20-7] | [95-47-6] | [108-38-3] | [106-42-3] |- ! {{chembox header}} align="center" colspan="5" | Properties |- | [[Density]] and [[Phase (matter)|phase]] | 0.864 g/mL, liquid | 0.88 g/mL, liquid | 0.86 g/mL, liquid | 0.86 g/mL, liquid |- | [[Soluble|Solubility]] in [[Water (molecule)|water]] | align="center" colspan="4" | practically insoluble |- | align="center" colspan="5" | Soluble in non-polar [[solvent]]s such as [[aromatic]] [[hydrocarbon]]s |- | [[Melting point]] | -47.4°C (-53.3°F; 226 K) | −25°C (-13°F; 248 K) | −48°C (-54.4°F; 225 K) | 13°C (55.4°F; 286 K) |- | [[Boiling point]] | 138.5°C (281.3°F; 412 K) | 144°C (291.2°F; 417 K) | 139°C (282.2°F; 412 K) | 138°C (280.4°F; 411 K) |- | [[Viscosity]] | | .812 c[[Poise|P]] at {{convert|20|°C|°F|0}} | .62 c[[Poise|P]] at {{convert|20|°C|°F|0}} | .34 c[[Poise|P]] at {{convert|30|°C|°F|0}} |- ! {{chembox header}} align="center" colspan="5" | Hazards <!-- Summary only- MSDS entry provides more complete information --> |- | [[Material safety data sheet|MSDS]] | [http://sciencelab.com/msds.php?msdsId=9927646 Xylenes] | [http://sciencelab.com/msds.php?msdsId=9927647 ''o''-Xylene] | [http://sciencelab.com/msds.php?msdsId=9927323 ''m''-Xylene] | [http://sciencelab.com/msds.php?msdsId=9927324 ''p''-Xylene] |- | [[Directive 67/548/EEC|EU Classification]] | align="center" colspan="4" | Harmful ('''Xn''') |- | [[NFPA 704]] | align="center" colspan="4" | {{ NFPA 704 | Health=2 | Flammability=3 | Reactivity=0 }} |- | [[Flash point]] | {{convert|24|°C|°F|0}} | {{convert|17|°C|°F|0}} | {{convert|25|°C|°F|0}} | {{convert|25|°C|°F|0}} |- | [[Risk and Safety Statements|R/S statement]] | align="center" colspan="4" | {{R10}}, {{R20/21}}, {{R38}}: {{S2}}, {{S25}} |- | [[RTECS]] number | | ZE2450000 | ZE2275000 | ZE2625000 |- ! {{chembox header}} align="center" colspan="5" | [[Xylene chemdata supplement|Supplementary data page]] |- | [[Xylene chemdata supplement#Structure and properties|Structure & properties]] | align="center" colspan="4" | [[Refractive index|''n'']], [[Dielectric constant|''ε<sub>r</sub>'']], etc. |- | [[Xylene chemdata supplement#Thermodynamic properties|Thermodynamic data]] | align="center" colspan="4" | Phase behaviour<br>Solid, liquid, gas |- | [[Xylene chemdata supplement#Spectral data|Spectral data]] | align="center" colspan="4" | [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[NMR spectroscopy|NMR]], [[Mass spectrometry|MS]] |- ! {{chembox header}} align="center" colspan="5" | Related compounds |- | Related [[aromatic]]<br>[[hydrocarbon]]s | align="center" colspan="4" | [[toluene]], [[mesitylene]], [[benzene]], [[ethylbenzene]] |- | Related compounds | align="center" colspan="4" | xylenols - types of [[phenols]] |- | {{chembox header}} align="center" colspan="5" | <small>Except where noted otherwise, data are given for<br> materials in their [[standard state|standard state (at 25°C, 100 kPa)]]<br/>[[wikipedia:Chemical infobox|Infobox disclaimer and references]]</small> |- |} ==Related compounds== Xylenes are a starting material for the production of other chemicals. For instance [[chlorination]] of both methyl groups gives three isomeric xylene dichlorides or 1,2-bis(chloromethyl)benzenes. With oxidizing agents, such as [[potassium permanganate]] (KMnO<sub>4</sub>), the methyl group can be oxidized to a [[carboxylic acid]]. By oxidizing both methyl groups, ''o''-xylene forms [[phthalic acid]] and ''p''-xylene forms [[terephthalic acid]]. In articles of commerce, the term '''xylol''' refers to the solvent mixture of three xylene isomers, sometimes containing ethylbenzene. In the chemical trade, this mixture is referred to as '''xylenes''' (plural). This substance must not be confused with the toxic and corrosive '''xyleneol''' compounds, which are dimethyl phenol isomers. ==Health effects== Xylene has an effect on the [[brain]]. High levels from exposure for short periods (14 days or less) or long periods (more than 1 year) can cause headaches, lack of muscle coordination, dizziness, confusion, and changes in one's sense of balance. Exposure of people to high levels of xylene for short periods can also cause irritation of the skin, eyes, nose, and throat; difficulty in breathing; problems with the lungs; delayed reaction time; memory difficulties; stomach discomfort; and possibly changes in the liver and kidneys. It can cause unconsciousness and even death at very high levels (see [[inhalants]]). Studies of unborn animals indicate that high concentrations of xylene may cause increased numbers of deaths, and delayed growth and development.{{Fact|date=December 2007}} In many instances, these same concentrations also cause damage to the mothers. It is not yet known whether xylene harms the unborn fetus if the mother is exposed to low levels of xylene during pregnancy. Besides [[occupational hygiene|occupational exposure]], the principal pathway of human contact is via [[soil contamination]] from leaking [[underground storage tank]]s containing petroleum products. Humans who come into contact with the soil or groundwater may become affected. Use of contaminated groundwater as a water supply could lead to adverse health effects. ==See also== *[[Water pollution]] *[[Toxicity]] *[[Gasoline]] == External links == *[http://www.ilo.org/public/english/protection/safework/cis/products/icsc/dtasht/_icsc00/icsc0084.htm International Chemical Safety Card 0084] (''o''-Xylene) *[http://www.ilo.org/public/english/protection/safework/cis/products/icsc/dtasht/_icsc00/icsc0085.htm International Chemical Safety Card 0085] (''m''-Xylene) *[http://www.ilo.org/public/english/protection/safework/cis/products/icsc/dtasht/_icsc00/icsc0086.htm International Chemical Safety Card 0086] (''p''-Xylene) *[http://www.cdc.gov/niosh/npg/npgd0668.html NIOSH Pocket Guide to Chemical Hazards] (''o''-Xylene) *[http://www.cdc.gov/niosh/npg/npgd0669.html NIOSH Pocket Guide to Chemical Hazards] (''m''-Xylene) *[http://www.cdc.gov/niosh/npg/npgd0670.html NIOSH Pocket Guide to Chemical Hazards] (''p''-Xylene) *{{ecb}} [[Category:Aromatic hydrocarbons]] [[Category:Hazardous air pollutants]] [[Category:Soil contamination]] [[Category:Hydrocarbon solvents]] [[ar:الزيلين]] [[bs:Ksilol]] [[cs:Xylen]] [[da:Xylen]] [[de:Xylole]] [[es:Xileno]] [[eo:Ksilolo]] [[fr:Xylène]] [[it:Xilene]] [[lv:Ksilols]] [[lt:Ksilenas]] [[nl:Xyleen]] [[ja:キシレン]] [[no:Xylen]] [[pl:Ksyleny]] [[pt:Xileno]] [[ro:Xylol]] [[ru:Диметилбензол]] [[fi:Ksyleeni]] [[sv:Xylen]] [[vi:Xylen]] [[zh:二甲苯]]