Names and identifiers
- IUPAC name
- pentane
- Synonyms
- n-Pentane, Pentan, Skellysolve A
+ 35 more
Pentanen, Pentani, Amyl hydride, Tetrafume, Tetrakil, Tetraspot, DTXSID2025846, 4FEX897A91, NSC-72415, DTXCID705846, CHEBI:37830, RefChem:6667, 203-692-4, Pentanes, npentane, Normal Pentane, MFCD00009498, NSC 72415, NCGC00091116-01, Pentan [Polish], Pentanen [Dutch], Pentani [Italian], Caswell No. 642AA, n-Pentan, CAS-109-66-0, High purity Pentane, 95% N-pentane, 99% N-pentane, HSDB 109, High purity N-pentane, blowing agent N-pentane, foaming agent N-pentane, ACTH, formylmethionyl-, EINECS 203-692-4, UN1265
- Molecular formula
- C5H12
- Empirical formula
- C5H12
- Molecular weight
- 72.15 g/mol
- Exact mass
- 72.09390
- CAS number
- 109-66-0
- PubChem CID
- 8003
- Canonical SMILES
- CCCCC
- Isomeric SMILES
- CCCCC
- InChI
- InChI=1S/C5H12/c1-3-5-4-2/h3-5H2,1-2H3
- InChIKey
- OFBQJSOFQDEBGM-UHFFFAOYSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Physical properties
- Appearance
- Colorless liquid [Note: A gas above 97 degrees F. May be utilized as a fuel].[6]
6 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source – N-pentane appears as a clear colorless liquid with a petroleum-like odor. Flash point -57 °F. Boiling point 97 °F. Less dense than water and insoluble in water. Hence floats on water. Vapors are heavier than air. [1] CAMEO Chemicals – Gas Vapor; Large Crystals; Liquid; Gas Vapor; Liquid [2] EPA Chemical Data Reporting (CDR) – COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR. [3] ILO-WHO International Chemical Safety Cards (ICSCs) – Colorless liquid with a gasoline-like odor. [4] Occupational Safety and Health Administration (OSHA) – Colorless liquid with a gasoline-like odor. [Note: A gas above 97 °F. May be utilized as a fuel.] [5] The National Institute for Occupational Safety and Health (NIOSH) –shown Colorless liquid [Note: A gas above 97 degrees F. May be utilized as a fuel]. [6] 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 - Odor
- Pleasant[6]
2 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source –shown Pleasant [6] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 955 – Gasoline-like odor [6] 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 - Melting point
- -129.8 °C[7]
5 values
5 of 5 sources agree on it (most common value).
Value As written Source −130 °C -202 °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. −129 °C -129 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs) −130 °C -202 °F [4] Occupational Safety and Health Administration (OSHA) −129.8 °Cshown -129.8 °C [7] PAC Chemical Database, U.S. Department of Energy −130 °C -202 °F [5] The National Institute for Occupational Safety and Health (NIOSH) - Boiling point
- 36.1 °C @760 [mmHg][7]
5 values
5 of 5 sources agree on it (most common value).
Value As written Source 36 °C 97 °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. 36 °C 36 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs) 36 °C 97 °F [4] Occupational Safety and Health Administration (OSHA) 36.1 °Cshown 36.1 °C @760 [mm Hg] [7] PAC Chemical Database, U.S. Department of Energy 36 °C 97 °F [5] The National Institute for Occupational Safety and Health (NIOSH) - Density
- 0.626 at 20 °C (68 °F) (USCG, 1999) - Less dense than water[1]
5 values
5 of 5 sources agree on it (most common value).
Value As written Source –shown 0.626 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): 0.63 [3] ILO-WHO International Chemical Safety Cards (ICSCs) – 0.63 [4] Occupational Safety and Health Administration (OSHA) – 0.62 @ 20°C [7] PAC Chemical Database, U.S. Department of Energy – 0.63 [5] The National Institute for Occupational Safety and Health (NIOSH) - Solubility in water
- Solubility in water, g/100ml at 20 °C: 0.004 (very poor)[3]
4 values
From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.
Value As written Source – less than 1 mg/mL at 70 °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. – In water, 38 mg/L at 25 °C [6] Hazardous Substances Data Bank (HSDB)cites Riddick, J.A., W.B. Bunger, Sakano T.K. Techniques of Chemistry 4th ed., Volume II. Organic Solvents. New York, NY: John Wiley and Sons., 1985. –shown Solubility in water, g/100ml at 20 °C: 0.004 (very poor) [3] ILO-WHO International Chemical Safety Cards (ICSCs) – 0.04% [5] The National Institute for Occupational Safety and Health (NIOSH) - log P
- 3.39[3]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source – log Kow = 3.39 [6] 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. 15 –shown 3.39 [3] ILO-WHO International Chemical Safety Cards (ICSCs) - Vapor pressure
- Vapor pressure, kPa at 18.5 °C: 53.3[3]
5 values
2 of 4 sources agree on it (most common value).
Value As written Source 400 mmHg 400 mmHg at 65.3 °F [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. 426 mmHg 426 mmHg at 68 °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. 514 mmHg 514 mm Hg at 25 °C [6] Hazardous Substances Data Bank (HSDB)cites Daubert, T.E., R.P. Danner. Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, D.C.: Taylor and Francis, 1989. 400 mmHgshown Vapor pressure, kPa at 18.5 °C: 53.3 [3] ILO-WHO International Chemical Safety Cards (ICSCs) 514 mmHg 514 [mm Hg] @25 °C [7] PAC Chemical Database, U.S. Department of Energy 2 more values were reported but failed the checks (unreadable or out of range), so they are not shown.
- Flash point
- -49 °C c.c.[3]
5 values
4 of 4 sources agree on it (most common value).
Value As written Source −49 °C -57 °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. < −40 °C <-40 °F (-40 °C) (Closed cup) [6] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-95 −49 °Cshown -49 °C c.c. [3] ILO-WHO International Chemical Safety Cards (ICSCs) −49 °C -57 °F [4] Occupational Safety and Health Administration (OSHA) −49 °C -57 °F [5] The National Institute for Occupational Safety and Health (NIOSH) - Autoignition temperature
- 260 °C[3]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source 260 °C 500 °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. 260 °C 500 °F (260 °C) [6] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-95 260 °Cshown 260 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs) - Viscosity
- Reported, but no value passed the checks.
The value and why
- 0,36 mm²/s (could not be read; source [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
- 5
- Rings
- 0
- Aromatic rings
- 0
- Fraction sp³ carbons (Fsp3)
- 1
- H-bond donors
- 0
- H-bond acceptors
- 0
- Rotatable bonds
- 2
- TPSA (Ų)
- 0
- Formal charge
- 0
- XLogP3
- 3.4 PubChem
- Complexity
- 7 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
- C83.24%
- H16.76%
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
- 2.2 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -1.54 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 1.7 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 72.15
- log P ≤ 5 (Crippen): 2.2
- 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
Danger
Harmonized EU classification (CLP Annex VI). Source [8].
Flammable
Harmful or irritant
Health hazard
Environmental hazard
- H225Highly Flammable liquid and vapor
- H304May be fatal if swallowed and enters airways
- H336May cause drowsiness or dizziness
- H411Toxic to aquatic life with long lasting effects
Precautionary statements: P210, P233, P240, P241, P242, P243, P261, P271, P273, P280, P301+P316, P303+P361+P353, P304+P340, P319, P331, P370+P378, P391, P403+P233, P403+P235, P405, P501
View all classifications (3)
- [8] Regulation (EC) No 1272/2008 of the European Parliament and of the Council · DangerH225, H304, H336, H411
- [9] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 0.8% (11 of 1378) of reports.
- [9] European Chemicals Agency (ECHA) · 1,378 reports · DangerH224, H225, H304, H336, H411
Exposure limits
- PEL-TWA (8-Hour Time Weighted Average): 1000 ppm (2950 mg/m³)[4]
- PEL: TWA 1000 ppm (2950 mg/m3) See Appendix G[5]
- REL-TWA (Time Weighted Average): 120 ppm (350 mg/m³)[4]
- REL-C (Ceiling): 610 ppm (1800 mg/m³) [15 min][4]
- REL: TWA 120 ppm (350 mg/m3) C 610 ppm (1800 mg/m3) [15-minute][5]
- TLV: 1000 ppm as TWA.[3]
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: · Call 911 or emergency medical service. · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination. · Move victim to fresh air if it can be done safely. · Administer oxygen if breathing is difficult. · If victim is not breathing: -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance. -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped…[10]
- (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: Water wash promptly - If this chemical contacts the skin, promptly wash the contaminated skin with water. If this chemical penetrates the clothing, promptly remove the clothing and wash the skin with water. If irritation persists after washing, get medical attention. Breathing: Respiratory support Swallow: Medical attention immediately - If this[5]
- Fresh air, rest. Refer for medical attention.[3]
Storage
Incompatibilities
Safety data sheets on the supplier’s page: Thermo Fisher Scientific, LGC Standards, Fluorochem.
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 · 90 MHz · CDCl3) · SpectraBase (Varian A-60)
- 13C NMRHuman Metabolome Database (HMDB) (NEVA · 15.09 MHz · CDCl3) · SpectraBase
- GC-MSHuman Metabolome Database (HMDB) (EI-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) (CI-B · positive)
- Other MSHazardous Substances Data Bank (HSDB) · MassBank Europe (HITACHI RMU-6M · EI-B · POSITIVE) · MassBank Europe (HITACHI M-80A · EI-B · POSITIVE) · MassBank Europe (FINNIGAN-MAT 4500 · CI-B · POSITIVE)
- IRHazardous Substances Data Bank (HSDB)
- FTIRSpectraBase (Layer between KBr)
- ATR-IRSpectraBase (ATR-Neat)
- Near IRSpectraBase (BRUKER IFS 88 · NIR Spectrometer= INSTRUMENT PARAMETERS=INST=BRUKER,RSN=7774,REO=2,CNM=HEI,ZFF=2)
- Vapor Phase IRSpectraBase (Bruker IFS 85 · Gas-GC)
- RamanSpectraBase
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]Occupational Safety and Health Administration (OSHA) · Public domain (US DOL) · via PubChem · retrieved 2026-10-14
- [5]The National Institute for Occupational Safety and Health (NIOSH) · Public domain (US CDC) · via PubChem · retrieved 2026-10-14
- [6]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
- [7]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · via PubChem · retrieved 2026-10-14
- [8]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
- [9]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
- [10]Emergency Response Guidebook (ERG) · Public domain (US DOT) · via PubChem · retrieved 2026-10-14
- [11]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
- [12]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
- [13]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
- [14]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
- [15]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
- [16]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.
