p-Xylene
Athanor · official
C8H10 · 106.16 g/mol
IUPAC name: 1,4-xylene
Also called xylene, 1,4-dimethylbenzene, para-xylene
WarningFlammable liquid and vapor · Harmful in contact with skin · Causes skin irritation · Harmful if inhaledNames and identifiers
- IUPAC name
- 1,4-xylene
- Synonyms
- xylene, 1,4-dimethylbenzene, para-xylene
+ 37 more
1,4-Dimethylbenzene, Para-Xylene, 1,4-Xylene, p-Methyltoluene, p-Dimethylbenzene, p-Xylol, Benzene, 1,4-dimethyl-, 4-Xylene, 4-Methyltoluene, Chromar, Scintillar, 1,4-Dimethylbenzol, paraxylene, DTXSID2021868, 6WAC1O477V, NSC-72419, DTXCID701868, CHEBI:27417, RefChem:103, 203-396-5, NSC 72419, CHEMBL31561, p-Xylene-alpha,alpha'-13C2, Xylene, p-, Benzene, p-dimethyl-, p-Xylenes, Xylene, p-isomer, PXY, CCRIS 910, HSDB 136, EINECS 203-396-5, UNII-6WAC1O477V, AI3-52255, p-Xylene solution, p-Xylene Standard, MFCD00008556, 1,4-dimethyl benzene
- Molecular formula
- C8H10
- Empirical formula
- C4H5
- Molecular weight
- 106.16 g/mol
- Exact mass
- 106.07825
- CAS number
- 106-42-3
- PubChem CID
- 7809
- Canonical SMILES
- CC1=CC=C(C=C1)C
- Isomeric SMILES
- CC1=CC=C(C=C1)C
- InChI
- InChI=1S/C8H10/c1-7-3-5-8(2)6-4-7/h3-6H,1-2H3
- InChIKey
- URLKBWYHVLBVBO-UHFFFAOYSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Physical properties
TemperaturePressureDensity
- Appearance
- Colorless liquid [Note: A solid below 56 degrees F][5]
6 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source – P-xylene appears as a colorless watery liquid with a sweet odor. Less dense than water. Insoluble in water. Irritating vapor. Freezing point is 56 °F. (USCG, 1999) [1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office. – Liquid [2] EPA Chemical Data Reporting (CDR) – COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR. [3] ILO-WHO International Chemical Safety Cards (ICSCs) – Colorless liquid with an aromatic odor. [Note: A solid below 56 °F.] [4] The National Institute for Occupational Safety and Health (NIOSH) –shown Colorless liquid [Note: A solid below 56 degrees F] [5] Hazardous Substances Data Bank (HSDB)cites NIOSH. NIOSH Pocket Guide to Chemical Hazards. Department of Health & Human Services, Centers for Disease Control & Prevention. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2010-168 (2010). Available from: https://www.cdc.gov/niosh/npg – Color: Saybolt units +30 (research, pure & technical grades) [5] Hazardous Substances Data Bank (HSDB)cites Flick, E.W. Industrial Solvents Handbook. 3rd ed. Park Ridge, NJ: Noyes Publications, 1985., p. 49 - Odor
- Sweet[5]
3 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source –shown Sweet [5] Hazardous Substances Data Bank (HSDB)cites NOAA; CAMEO Chemicals. Database of Hazardous Materials. p-Xylene (106-42-3). Natl Ocean Atmos Admin, Off Resp Rest; NOAA Ocean Serv. Available from, as of June 27, 2016: https://cameochemicals.noaa.gov/ – Aromatic odor [5] Hazardous Substances Data Bank (HSDB)cites NIOSH. NIOSH Pocket Guide to Chemical Hazards. Department of Health & Human Services, Centers for Disease Control & Prevention. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2010-168 (2010). Available from: https://www.cdc.gov/niosh/npg – Characteristic odor [5] Hazardous Substances Data Bank (HSDB)cites CDC; International Chemical Safety Cards (ICSC) 2012. Atlanta, GA: Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health (NIOSH). Ed Info Div. Available from, as of June 27, 2016: https://www.cdc.gov/niosh/ipcs/ - Melting point
- 13.3 °C (55.9 °F, NTP 1992)[1]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source 13.3 °Cshown 55.9 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina. 13 °C 13 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs) 13 °C 56 °F [4] The National Institute for Occupational Safety and Health (NIOSH) - Boiling point
- 138.3 °C (280.9 °F) at 760 mmHg (NTP, 1992)[1]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source 138.3 °Cshown 280.9 °F at 760 mmHg (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina. 138 °C 138 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs) 138 °C 281 °F [4] The National Institute for Occupational Safety and Health (NIOSH) - Density
- 0.861 at 20 °C (68 °F) (USCG, 1999) - Less dense than water[1]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source –shown 0.861 at 68 °F (USCG, 1999) - Less dense than water [1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office. – Relative density (water = 1): 0.86 (20 °C) [3] ILO-WHO International Chemical Safety Cards (ICSCs) – 0.86 [4] The National Institute for Occupational Safety and Health (NIOSH) 2 more values were reported but failed the checks (unreadable or out of range), so they are not shown.
- Solubility in water
- Solubility in water, g/l at 25 °C: 0.2 (very slightly soluble)[3]
5 values
From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.
Value As written Source – Insoluble. (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina. – In water, 1.62X10+2 mg/L at 25 °C [5] Hazardous Substances Data Bank (HSDB)cites Sanemasa I et al; Bull Chem Soc Jpn 18: 1111-230 (1982) – In water, 165 mg/L at 25 °C (average of 15 literature values ranging from 130-215 mg/L at 25 °C) [5] Hazardous Substances Data Bank (HSDB)cites Yalkowsky, S.H., He, Yan, Jain, P. Handbook of Aqueous Solubility Data Second Edition. CRC Press, Boca Raton, FL 2010, p. 500 –shown Solubility in water, g/l at 25 °C: 0.2 (very slightly soluble) [3] ILO-WHO International Chemical Safety Cards (ICSCs) – 0.02% [4] The National Institute for Occupational Safety and Health (NIOSH) - log P
- 3.15[3]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source – log Kow = 3.15 [5] Hazardous Substances Data Bank (HSDB)cites Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 43 –shown 3.15 [3] ILO-WHO International Chemical Safety Cards (ICSCs) - Vapor pressure
- 8.84 mmHg at 25 °C[5]
3 values
Sources disagree; from Hazardous Substances Data Bank (HSDB), the most authoritative.
Value As written Source 10 mmHg 10 mmHg at 81.1 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina. 8.84 mmHgshown 8.84 mm Hg at 25 °C [5] Hazardous Substances Data Bank (HSDB)cites Chao J et al; J Phys Chem Ref Data 12: 1033-66 (1983) 6.8 mmHg Vapor pressure, kPa at 20 °C: 0.9 [3] ILO-WHO International Chemical Safety Cards (ICSCs) 1 more value was reported but failed the checks (unreadable or out of range), so it is not shown.
- Flash point
- 25.0 °C (77.0 °F) - closed cup[5]
5 values
2 of 4 sources agree on it (most common value).
Value As written Source 27 °C 81 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina. 25.0 °Cshown 25.0 °C (77.0 °F) - closed cup [5] Hazardous Substances Data Bank (HSDB)cites Sigma-Aldrich; Safety Data Sheet for p-Xylene. Product Number: 95680, Version 3.9 (Revision Date 05/23/2016). Available from, as of July 1, 2016: https://www.sigmaaldrich.com/safety-center.html 25 °C 77 °F (25 °C) (Closed cup) [5] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-117 25 °C 25 °C c.c. [3] ILO-WHO International Chemical Safety Cards (ICSCs) 27 °C 81 °F [4] The National Institute for Occupational Safety and Health (NIOSH) - Autoignition temperature
- 528 °C (984 °F)[5]
3 values
2 of 3 sources agree on it (most common value).
Value As written Source 529 °C 984 °F (USCG, 1999) [1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office. 529 °Cshown 984 °F (528 °C) [5] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-117 540 °C 540 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs) - Viscosity
- 0.65 mPa*s at 20 °C[3]
Each value as its source reports it, with the source's number after it (listed under References). Where several sources report a property, the row shows the value most of them agree on, the rule the app uses; open the values to see every one.
Calculated
- Heavy atoms
- 8
- Rings
- 1
- Aromatic rings
- 1
- Fraction sp³ carbons (Fsp3)
- 0.25
- H-bond donors
- 0
- H-bond acceptors
- 0
- Rotatable bonds
- 0
- TPSA (Ų)
- 0
- Formal charge
- 0
- XLogP3
- 3.2 PubChem
- Complexity
- 48 PubChem
- Stereocenters
- None
- Double-bond geometry
- None specified
- Point group
- C2v of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)
Elemental analysis
- C90.51%
- H9.49%
Isotope pattern
Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.
Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.
Predicted
- log P
- 2.3 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -2.5 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 1 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 106.17
- log P ≤ 5 (Crippen): 2.3
- H-bond donors ≤ 5: 0
- H-bond acceptors ≤ 10: 0
Passes all four rules.
¹³C NMR shifts, predicted
Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.
Safety
Warning
Harmonized EU classification (CLP Annex VI). Source [6].
- Flammable
- Harmful or irritant
- H226Flammable liquid and vapor
- H312Harmful in contact with skin
- H315Causes skin irritation
- H332Harmful if inhaled
Precautionary statements: P210, P233, P240, P241, P242, P243, P261, P264, P271, P280, P302+P352, P303+P361+P353, P304+P340, P317, P321, P332+P317, P362+P364, P370+P378, P403+P235, P501
View all classifications (5)
- [6] Regulation (EC) No 1272/2008 of the European Parliament and of the Council · WarningH226, H312, H315, H332
- [7] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 0.8% (11 of 1380) of reports.
- [7] European Chemicals Agency (ECHA) · 1,380 reports · DangerH226, H304, H312+H332, H312, H315, H319, H332, H335, H412
- [7] European Chemicals Agency (ECHA) · 39 reports · WarningH226, H312+H332, H312, H315, H332
- [5] Hazardous Substances Data Bank (HSDB) · WarningH226, H312, H315, H332, H401
Exposure limits
First aid
- Eyes: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. Immediately transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop. Skin: Immediately flood affected skin with water while removing and isolating all contaminated clothing.[1]
- (General first aid procedures) Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately. Skin: Soap wash promptly - If this chemical contacts the skin, promptly wash the contaminated skin with soap and water. If this chemical penetrates the clothing, promptly remove the clothing and wash the skin with soap and water.[4]
- Fresh air, rest. Refer for medical attention.[3]
- First rinse with plenty of water for at least 15 minutes, then remove contaminated clothes and rinse again. Rinse and then wash skin with water and soap.[3]
Storage
- Fireproof. Store only in original container. Separated from strong oxidants and strong acids. Store in an area without drain or sewer access.[3]
- Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage.[5]
- Ambient storage temp and open (flame arrester), or pressure-vacuum.[5]
Incompatibilities
- Incompatible materials: Strong oxidizing agents.[5]
- In liquid phase aerobic oxidation of p-xylene in acetic acid to terephthalic acid, it is important to eliminate the inherent hazards of this fuel-air mixture. Effects of temp, pressure and presence of steam on explosive limits of the mixture have been investigated.[5]
- Oxidation of p-xylene with nitric acid under pressure in manufacture of terephthalic acid is an explosion hazard in autoclaves and condensing systems.[5]
- Can react with oxidizing materials.[5]
Safety data sheets on the supplier’s page: Thermo Fisher Scientific, Achemtek, Sigma-Aldrich.
Always read the supplier’s safety data sheet before working with it.
Spectra
- NMRHazardous Substances Data Bank (HSDB) · NMRShiftDB
- 1H NMRHuman Metabolome Database (HMDB) (JEOL · 300 MHz · CDCl3) · SpectraBase (Varian A-60)
- 13C NMRHuman Metabolome Database (HMDB) (Varian · 25.16 MHz · CDCl3) · SpectraBase
- GC-MSHuman Metabolome Database (HMDB) (CI-B · positive) · Human Metabolome Database (HMDB) (EI-B · positive) · Human Metabolome Database (HMDB) (EI-B · positive) · Human Metabolome Database (HMDB) (CI-B · positive) · Human Metabolome Database (HMDB) (EI-B · positive) · Human Metabolome Database (HMDB) (EI-B · positive)
- Other MSHazardous Substances Data Bank (HSDB) · MassBank Europe (HITACHI RMU-7M · EI-B · POSITIVE) · MassBank Europe (HITACHI RMU-6M · EI-B · POSITIVE) · MassBank Europe (FINNIGAN-MAT 4500 · CI-B · POSITIVE)
- UVHazardous Substances Data Bank (HSDB)
- IRHazardous Substances Data Bank (HSDB)
- FTIRSpectraBase (DIGILAB FTS-40 · NEAT)
- ATR-IRSpectraBase (Bio-Rad FTS · ATR-Neat (DuraSamplIR II))
- Near IRSpectraBase (BRUKER IFS 88 · NIR)
- Vapor Phase IRSpectraBase (Bruker IFS 85 · Gas-GC)
- RamanHazardous Substances Data Bank (HSDB) · SpectraBase (FT-Raman)
Experimental spectra held by these sources; each link opens the source's own record.
Literature
Reading PubChem, OpenAlex and GSRS…
Bioactivity
Reading ChEMBL…
References
- [1]CAMEO Chemicals · Public domain (NOAA) · via PubChem · retrieved 2026-10-14
- [2]EPA Chemical Data Reporting (CDR) · Public domain (US EPA) · via PubChem · retrieved 2026-10-14
- [3]ILO-WHO International Chemical Safety Cards (ICSCs) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
- [4]The National Institute for Occupational Safety and Health (NIOSH) · Public domain (US CDC) · via PubChem · retrieved 2026-10-14
- [5]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
- [6]Regulation (EC) No 1272/2008 of the European Parliament and of the Council · EU reuse policy, CC BY 4.0 · via PubChem · retrieved 2026-10-14
- [7]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
- [8]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
- [9]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
- [10]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
- [11]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
- [12]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
- [13]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
- ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
- ·Literature on PubChem
Data last updated 2026-10-14.