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Skeletal formula
Space-filling model
Preferred IUPAC name
Systematic IUPAC name
Other names
3D model (JSmol)
ECHA InfoCard 100.003.252
RTECS number ZE2275000
Molar mass 106.16 g/mol
Appearance Colorless liquid
Density 0.86 g/mL
Melting point −48 °C (−54 °F; 225 K)
Boiling point 139 °C (282 °F; 412 K)
Solubility in ethanol very soluble
Solubility in diethyl ether very soluble
Vapor pressure 9 mmHg (20°C)[1]
-76.56·10−6 cm3/mol
Viscosity 0.8059 cP at 0 °C
0.6200 cP at 20 °C
0.33-0.37 D[2]
Main hazards Harmful or fatal if swallowed. Vapor harmful. Flammable liquid and vapor.
Safety data sheet See: data page
External MSDS
R-phrases (outdated) R10 R20 R21 R38
S-phrases (outdated) S25
NFPA 704
Flammability code 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g., gasoline Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point 27 °C (81 °F; 300 K) [3]
527 °C (981 °F; 800 K)[3]
Explosive limits 1.1%-7.0%[1]
100 ppm[3] (TWA), 150 ppm[3] (STEL)
Lethal dose or concentration (LD, LC):
2010 ppm (mouse, 24 hr)
8000 ppm (rat, 4 hr)[4]
US health exposure limits (NIOSH):
PEL (Permissible)
TWA 100 ppm (435 mg/m3)[1]
REL (Recommended)
TWA 100 ppm (435 mg/m3) ST 150 ppm (655 mg/m3)[1]
IDLH (Immediate danger)
900 ppm[1]
Related compounds
Supplementary data page
Refractive index (n),
Dielectric constantr), etc.
Phase behaviour
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YesYN ?)
Infobox references

m-Xylene (meta-xylene) is an aromatic hydrocarbon. It is one of the three isomers of dimethylbenzene known collectively as xylenes, the m- stands for meta-, indicating that the two methyl groups in m-xylene occupy positions 1 and 3 on a benzene ring. It is in the positions of the two methyl groups, their arene substitution pattern, that it differs from the other isomers, o-xylene and p-xylene. All have the same chemical formula C6H4(CH3)2. All xylene isomers are colorless and highly flammable.[5]

Production and use[edit]

Petroleum contains about 1 weight percent xylenes.[6]

The major use of meta-xylene is in the production of isophthalic acid, which is used as a copolymerizing monomer to alter the properties of polyethylene terephthalate. The conversion m-xylene to isophthalic acid entails catalytic oxidation. meta-Xylene is also used as a raw material in the manufacture of 2,4- and 2,6-xylidine as well as a range of smaller-volume chemicals.[7][5]

Toxicity and exposure[edit]

Xylenes are not acutely toxic, for example the LD50 (rat, oral) is 4300 mg/kg. Effects vary with animal and xylene isomer. Concerns with xylenes focus on narcotic effects.[5]


  1. ^ a b c d e "NIOSH Pocket Guide to Chemical Hazards #0669". National Institute for Occupational Safety and Health (NIOSH). 
  2. ^ DeanHandb, Lange´s Handbook of chemistry, 15th edition,1999.
  3. ^ a b c d "m-Xylene". International Chemical Safety Cards. IPCS/NIOSH. July 1, 2014. 
  4. ^ "Xylene (o-, m-, p-isomers)". Immediately Dangerous to Life and Health. National Institute for Occupational Safety and Health (NIOSH). 
  5. ^ a b c Fabri, Jörg;; Graeser, Ulrich; Simo, Thomas A. (2000). "Xylenes]". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a28_433. 
  6. ^ EPA-454/R-93-048 Locating and estimating air emissions from sources of xylene Emission Inventory Branch Technical Support Division Office of Air Quality Planning and Standards U.S. Environmental Protection Agency March 1994
  7. ^ Ashford's Dictionary of Industrial Chemicals, third edition, page 9692.