Cresol
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robot Removing: [[tr:Kresol]] Modifying: [[nl:Cresol]]
'''Cresols''' are [[organic compound]]s which are [[methyl group|methyl]][[phenol]]s. They are a widely occurring natural and manufactured group of [[aromatic]] [[organic compound]]s which are categorized as [[phenols]] (sometimes called ''phenolics''). Depending on the [[temperature]], cresols can be [[solid]] or [[liquid]] because they have [[melting point]]s not far from room temperature. Like other types of phenols, they are slowly [[oxidation|oxidized]] by long exposure to [[air]] and the impurities often give cresols a yellowish to brownish red tint. Cresols have an [[odor]] characteristic to that of other simple phenols, reminiscent to some of a "medicine" smell.
== Chemical structure ==
In its [[chemical structure]], a cresol [[molecule]] has a [[methyl group]] substituted onto the [[benzene ring]] of a [[phenol]] molecule. There are three forms of cresols that are only slightly different in their chemical structure: '''''ortho''-cresol''' ([[o-Cresol|''o''-cresol]]), '''''meta''-cresol''' ([[m-Cresol|''m''-cresol]]), and '''''para''-cresol''' ([[p-Cresol|''p''-cresol]]). These forms occur separately or as a mixture.
<center>
{| 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="4" | Isomers of Cresol
|-
| [[Skeletal formula]]
| <center>[[Image:Ortho-cresol-2D-skeletal.png|80px]]</center>
| <center>[[Image:Meta-cresol-2D-skeletal.png|80px]]</center>
| <center>[[Image:Para-cresol-vertical-2D-skeletal.png|60px]]</center>
|-
| [[Ball-and-stick model]]
| [[Image:Ortho-cresol-3D-balls.png|100px]]
| [[Image:Meta-cresol-3D-balls.png|100px]]
| [[Image:Para-cresol-3D-balls.png|100px]]
|-
! {{chembox header}} align="center" colspan="4" | General
|-
| Common name
| '''''o''-cresol'''
| '''''m''-cresol'''
| '''''p''-cresol'''
|-
| [[IUPAC nomenclature|Systematic name]]
| 2-methylphenol
| 3-methylphenol
| 4-methylphenol
|-
| Other names
| ''ortho''-cresol
| ''meta''-cresol
| ''para''-cresol
|-
| [[Chemical formula|Molecular formula]]
| align="center" colspan="4" | C<sub>7</sub>H<sub>8</sub>O
|-
| [[Simplified molecular input line entry specification|SMILES]]
| Oc1c(C)cccc1
| Oc1cc(C)ccc1
| Oc1ccc(C)cc1
|-
| [[Molar mass]]
| align="center" colspan="4" | 108.14 g/mol
|-
| Appearance at room<br> temperature and pressure
| greasy-looking solid <br>ready to melt <br>on hot day
| thicker liquid
| greasy-looking solid
|-
|rowspan="2" | [[CAS registry number|CAS number]]
| <nowiki>[95-48-7]</nowiki>
| <nowiki>[108-39-4]</nowiki>
| <nowiki>[106-44-5]</nowiki>
|-
| align="center" colspan="3" | mixture of cresols: <nowiki>[1319-77-3]</nowiki>
|-
! {{chembox header}} align="center" colspan="4" | Properties
|-
| [[Density]] and [[Phase (matter)|phase]]
| 1.05 g/cm<sup>3</sup>, solid
| 1.03 g/cm<sup>3</sup>, liquid
| 1.02 g/cm<sup>3</sup>, liquid
|-
| [[Soluble|Solubility]] in [[Water (molecule)|pure water]]<br> at 20-25°C
| 2.5 g/100 ml
| 2.4 g/100 ml
| 1.9 g/100 ml
|-
| align="center" colspan="4" | soluble in strongly [[alkaline]] water
|-
<!-- | Other solvents e.g. [[ethanol]], [[acetone]] -->
<!-- | solubility info on other solvents -->
<!-- |- -->
| [[Melting point]]
| 29.8 °C (303.0 K)
| 11.8 °C (285.0 K)
| 35.5 °C (309.7 K)
|-
| [[Boiling point]]
| 191.0 °C (464.2 K)
| 202.0 °C (475.2 K)
| 201.9 °C (475.1 K)
|-
| [[Acid dissociation constant|Acidity]] (p''K''<sub>a</sub>) <!-- omit if not an acid or a base. If several values, be clear -->
| 10.26
| 10.99
| 10.26
|-
| [[Viscosity]]
| solid at 25 °C
| ? c[[Poise|P]] at 25 °C
| solid at 25 °C
|-
! {{chembox header}} align="center" colspan="4" | Structure
|-
| [[Dipole#Molecular dipoles|Dipole moment]]
| ? [[Debye|D]]
| ? [[Debye|D]]
| ? [[Debye|D]]
|-
! {{chembox header}} align="center" colspan="4" | Hazards <!-- Summary only- MSDS entry provides more complete information -->
|-
| [[Material safety data sheet|MSDS]]
| [[Cresol chemdata supplement#Material Safety Data Sheet|External MSDS]] <!-- please replace with proper link-->
| ?
| ?
|-
| Main [[Worker safety and health|hazard]]s
| align="center" colspan="4" | [[flammable]], ingestion and inhalation toxicity hazard
|-
| [[Flash point]]
| 81°C c.c.
| 86 °C
| 86 °C c.c.
|-
| [[Risk and Safety Statements|R/S statement]]
| align="center" colspan="4" | R: 24/25-34 S: (1/2-)36/37/39-45
|-
| [[RTECS]] number
| ?
| ?
| ?
|-
! {{chembox header}} align="center" colspan="4" | [[Cresol chemdata supplement|Supplementary data page]]
|-
| [[Cresol chemdata supplement#Structure and properties|Structure & properties]]
| [[Refractive index|''n'']], [[Dielectric constant|''ε<sub>r</sub>'']], etc.
|-
| [[Cresol chemdata supplement#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour<br>Solid, liquid, gas
|-
| [[Cresol chemdata supplement#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[NMR spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} align="center" colspan="4" | Related compounds
|-
| Related [[phenols]]
| [[phenol]], xylenols
|-
| Related compounds
| ?
|-
| {{chembox header}} align="center" colspan="4" | <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>
|-
|}
</center>
== Applications ==
Cresols are used to [[solvation|dissolve]] other chemicals, as [[disinfectant]]s and [[deodorizer]]s, and to make specific chemicals that kill [[insect]] [[Pest (animal)|pest]]s.
Cresol solutions are used as household cleaners and disinfectants, perhaps most famously under the trade name [[Lysol]]. In the past, cresol solutions have been used as [[antiseptic]]s in [[surgery]], but they have been largely displaced in this role by less toxic compounds. Lysol was also advertised as a disinfecting vaginal [[douche]] in mid-twentieth century America<ref>[http://www.flickr.com/photos/mrbill/sets/834100/ "Lysol Douche Advertisements"]</ref>.
Cresols are found in many foods and in wood and [[tobacco smoke]], [[crude oil]], [[coal tar]], and in brown mixtures such as [[creosote]], [[cresolene]] and [[cresylic acid]]s, which are wood [[preservative]]s. Small organisms in soil and water produce cresols when they break down materials in the environment.
[[Xylenol]]s are dimethylphenols, or they can be thought of as methylcresols.
p-cresol is one of the very few compounds to attract the [[Euglossini|orchid bee]] ''[[Euglossa]] [[Euglossa cyanura|cyanura]]'', and has been used to capture and study the species<ref>Williams & Whitten, 1983: 387</ref>.
==Health effects==
Most exposures to cresols are at very low levels that are not harmful. When cresols are breathed, ingested, or applied to the [[skin]] at very high levels, they can be very harmful. Effects observed in people include [[irritation]] and burning of skin, [[eye]]s, [[mouth]], and [[throat]]; abdominal pain and vomiting; [[heart]] damage; [[anemia]]; [[liver]] and [[kidney]] damage; facial paralysis; [[coma]]; and [[death]].
Breathing high levels of cresols for a short time results in irritation of the [[nose]] and throat. Aside from these effects, very little is known about the effects of breathing cresols, for example, at lower levels over longer times.
Ingesting high levels results in kidney problems, mouth and throat burns, abdominal pain, vomiting, and effects on the [[blood]] and [[nervous system]].
Skin contact with high levels of cresols can burn the skin and damage the kidneys, liver, blood, [[brain]], and [[lung]]s.
Short-term and long-term studies with animals have shown similar effects from exposure to cresols. No human or animal studies have shown harmful effects from cresols on the ability to have children.
It is not known what the effects are from long-term ingestion or skin contact with low levels of cresols.
==References for Table of Properties==
*[http://www.inchem.org/documents/icsc/icsc/eics0030.htm o-CRESOL (ICSC)]
*[http://www.inchem.org/documents/icsc/icsc/eics0646.htm m-CRESOL (ICSC)]
*[http://www.inchem.org/documents/icsc/icsc/eics0031.htm p-CRESOL (ICSC)]
*[http://www.syrres.com/esc/smiles_ex_notations.htm Environmental Science - SMILES Examples Notations]
==Footnotes==
{{reflist}}
==References==
* {{aut|Williams, Norris H. & Whitten, W. Mark}} (1983): Orchid floral fragrances and male euglossine bees: methods and advances in the last sesquidecade. ''Biol. Bull.'' '''164''': 355-395.
[[Category:Phenols]]
[[Category:Antiseptics]]
[[Category:Hazardous air pollutants]]
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