Piperidine (C5H11N): structure, properties and hazards

Names and identifiers

IUPAC name: piperidine
Synonyms: hexahydropyridine, azinane, Hexahydropyridine
+ 35 more
Cyclopentimine, Azacyclohexane, Hexazane, Cypentil, Pentamethyleneimine, Piperidin, Pentamethylenimine, Perhydropyridine, Pyridine, hexahydro-, FEMA No. 2908, DTXSID6021165, 67I85E138Y, DTXCID101165, CHEBI:18049, RefChem:6144, 203-813-0, Pentamethyleneamine, piperdine, Piperidine, homopolymer, MFCD00005979, CHEMBL15487, Piperidin [German], CCRIS 967, HSDB 114, Piperidine, puriss. p.a., >=99.0% (GC/T), EINECS 203-813-0, UN2401, piperadine, pyperidine, N-piperidine, AI3-24114, UNII-67I85E138Y, Piperidine [UN2401] [Corrosive], Piperidine, 99%, PIPERIDINE [MI]
Molecular formula: C₅H₁₁N
Empirical formula: C₅H₁₁N
Molecular weight: 85.15 g/mol
Exact mass: 85.08915
CAS number: 110-89-4
PubChem CID: 8082
Canonical SMILES: C1CCNCC1
Isomeric SMILES: C1CCNCC1
InChI: InChI=1S/C5H11N/c1-2-4-6-5-3-1/h6H,1-5H2
InChIKey: NQRYJNQNLNOLGT-UHFFFAOYSA-N
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Physical properties

TemperaturePressureDensity

Appearance: Piperidine appears as a clear colorless liquid with a pepper-like odor. Less dense than water, but miscible in water. Will float on water. Flash point 37 °F. Melting point -15.8 °F (-9 °C). Boiling point 222.8 °F (106 °C). May severely irritate skin and eyes. May be toxic by ingestion and inhalation. Vapors heavier than air. Used to make rubber and as a solvent.[1]
4 values
From CAMEO Chemicals, the most authoritative source here.
Value As written Source
–shown Piperidine appears as a clear colorless liquid with a pepper-like odor. Less dense than water, but miscible in water. Will float on water. Flash point 37 °F. Melting point -15.8 °F (-9 °C). Boiling point 222.8 °F (106 °C). May severely irritate skin and eyes. May be toxic by ingestion and inhalation. Vapors heavier than air. Used to make rubber and as a solvent. [1] CAMEO Chemicals
– Liquid [2] EPA Chemical Data Reporting (CDR)
– COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR. [3] ILO-WHO International Chemical Safety Cards (ICSCs)
– CLEAR, COLORLESS LIQUID [4] Hazardous Substances Data Bank (HSDB)cites Sax, N.I. Dangerous Properties of Industrial Materials. 6th ed. New York, NY: Van Nostrand Reinhold, 1984., p. 2236
Odor: Odor of pepper[4]
3 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– AMINE-LIKE ODOR [4] Hazardous Substances Data Bank (HSDB)cites Sax, N.I. Dangerous Properties of Industrial Materials. 6th ed. New York, NY: Van Nostrand Reinhold, 1984., p. 2236
– HEAVY, SWEET, FLORAL, ANIMAL ODOR [4] Hazardous Substances Data Bank (HSDB)cites Fenaroli's Handbook of Flavor Ingredients. Volume 2. Edited, translated, and revised by T.E. Furia and N. Bellanca. 2nd ed. Cleveland: The Chemical Rubber Co., 1975., p. 487
–shown Odor of pepper [4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 14th Edition. John Wiley & Sons, Inc. New York, NY 2001., p. 882
Melting point: -9 °C[5]
3 values
2 of 3 sources agree on it (most common value).
Value As written Source
−9 to −7 °C 16 to 19 °F (EPA, 1998) [1] CAMEO Chemicalscites U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
−7 °C -7 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
−9 °Cshown -9 °C [5] PAC Chemical Database, U.S. Department of Energy
Boiling point: 106 °C[3]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source
106 °C 223 °F at 760 mmHg (EPA, 1998) [1] CAMEO Chemicalscites U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
106 °Cshown 106 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
106 °C 106 °C @760 [mm Hg] [5] PAC Chemical Database, U.S. Department of Energy
Density: 0.8622 @25 °C[5]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source
– 0.8622 at 68 °F (EPA, 1998) - Less dense than water [1] CAMEO Chemicalscites U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
– Relative density (water = 1): 0.86 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
–shown 0.8622 @25 °C [5] PAC Chemical Database, U.S. Department of Energy
Solubility in water: Solubility in water: miscible[3]
3 values
From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.
Value As written Source
– Miscible (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.
– Miscible in water [4] Hazardous Substances Data Bank (HSDB)cites Yalkowsky SH, Dannenfelser RM; The AQUASOL dATAbASE of Aqueous Solubility. Ver 5. Tucson, AZ: Univ AZ, College of Pharmacy (1992)
–shown Solubility in water: miscible [3] ILO-WHO International Chemical Safety Cards (ICSCs)
log P: 0.84[3]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
– log Kow = 0.84 [4] 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 0.84 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
Vapor pressure: Vapor pressure, kPa at 29.2 °C: 5.3[3]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source
40 mmHg 40 mmHg at 84.56 °F (EPA, 1998) [1] CAMEO Chemicalscites U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
39.8 mmHgshown Vapor pressure, kPa at 29.2 °C: 5.3 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
40 mmHg 40 [mm Hg] @29.2 °C [5] PAC Chemical Database, U.S. Department of Energy
Flash point: 16 °C c.c.[3]
3 values
2 of 3 sources agree on it (most common value).
Value As written Source
3.0 to 16.1 °C 37.4 to 61 °F (EPA, 1998) [1] CAMEO Chemicalscites U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
16 °C 61 °F (16 °C) (closed cup) [4] Hazardous Substances Data Bank (HSDB)cites Fire Protection Guide to Hazardous Materials. 13 ed. Quincy, MA: National Fire Protection Association, 2002., p. 325-99
16 °Cshown 16 °C c.c. [3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–shown	Piperidine appears as a clear colorless liquid with a pepper-like odor. Less dense than water, but miscible in water. Will float on water. Flash point 37 °F. Melting point -15.8 °F (-9 °C). Boiling point 222.8 °F (106 °C). May severely irritate skin and eyes. May be toxic by ingestion and inhalation. Vapors heavier than air. Used to make rubber and as a solvent.	[1] CAMEO Chemicals
–	Liquid	[2] EPA Chemical Data Reporting (CDR)
–	COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR.	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–	CLEAR, COLORLESS LIQUID	[4] Hazardous Substances Data Bank (HSDB)cites Sax, N.I. Dangerous Properties of Industrial Materials. 6th ed. New York, NY: Van Nostrand Reinhold, 1984., p. 2236

Value	As written	Source
–	AMINE-LIKE ODOR	[4] Hazardous Substances Data Bank (HSDB)cites Sax, N.I. Dangerous Properties of Industrial Materials. 6th ed. New York, NY: Van Nostrand Reinhold, 1984., p. 2236
–	HEAVY, SWEET, FLORAL, ANIMAL ODOR	[4] Hazardous Substances Data Bank (HSDB)cites Fenaroli's Handbook of Flavor Ingredients. Volume 2. Edited, translated, and revised by T.E. Furia and N. Bellanca. 2nd ed. Cleveland: The Chemical Rubber Co., 1975., p. 487
–shown	Odor of pepper	[4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 14th Edition. John Wiley & Sons, Inc. New York, NY 2001., p. 882

Value	As written	Source
−9 to −7 °C	16 to 19 °F (EPA, 1998)	[1] CAMEO Chemicalscites U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
−7 °C	-7 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
−9 °Cshown	-9 °C	[5] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
106 °C	223 °F at 760 mmHg (EPA, 1998)	[1] CAMEO Chemicalscites U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
106 °Cshown	106 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
106 °C	106 °C @760 [mm Hg]	[5] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
–	0.8622 at 68 °F (EPA, 1998) - Less dense than water	[1] CAMEO Chemicalscites U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
–	Relative density (water = 1): 0.86	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–shown	0.8622 @25 °C	[5] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
–	Miscible (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.
–	Miscible in water	[4] Hazardous Substances Data Bank (HSDB)cites Yalkowsky SH, Dannenfelser RM; The AQUASOL dATAbASE of Aqueous Solubility. Ver 5. Tucson, AZ: Univ AZ, College of Pharmacy (1992)
–shown	Solubility in water: miscible	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–	log Kow = 0.84	[4] 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	0.84	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
40 mmHg	40 mmHg at 84.56 °F (EPA, 1998)	[1] CAMEO Chemicalscites U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
39.8 mmHgshown	Vapor pressure, kPa at 29.2 °C: 5.3	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
40 mmHg	40 [mm Hg] @29.2 °C	[5] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
3.0 to 16.1 °C	37.4 to 61 °F (EPA, 1998)	[1] CAMEO Chemicalscites U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
16 °C	61 °F (16 °C) (closed cup)	[4] Hazardous Substances Data Bank (HSDB)cites Fire Protection Guide to Hazardous Materials. 13 ed. Quincy, MA: National Fire Protection Association, 2002., p. 325-99
16 °Cshown	16 °C c.c.	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

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: 6
Rings: 1
Aromatic rings: 0
Fraction sp³ carbons (Fsp3): 1
H-bond donors: 1
H-bond acceptors: 1
Rotatable bonds: 0
TPSA (Å²): 12
Formal charge: 0
XLogP3: 0.8 PubChem
Complexity: 30 PubChem
Stereocenters: None
Double-bond geometry: None specified
Point group: Cs of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

C70.53%
H13.02%
N16.45%

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: 0.76 Crippen (Wildman and Crippen 1999)
log S (water solubility): -0.85 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 2.06 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 85.15
log P ≤ 5 (Crippen): 0.76
H-bond donors ≤ 5: 1
H-bond acceptors ≤ 10: 1

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 [6].

Flammable
Corrosive
Acute toxicity

NFPA 704[4]

H225Highly Flammable liquid and vapor
H311Toxic in contact with skin
H314Causes severe skin burns and eye damage
H331Toxic if inhaled

Precautionary statements: P210, P233, P240, P241, P242, P243, P260, P261, P262, P264, P270, P271, P280, P301+P330+P331, P302+P352, P302+P361+P354, P303+P361+P353, P304+P340, P305+P354+P338, P316, P321, P361+P364, P363, P370+P378, P403+P233, P403+P235, P405, P501

View all classifications (2)

[6] Regulation (EC) No 1272/2008 of the European Parliament and of the Council · DangerH225, H311, H314, H331
[7] European Chemicals Agency (ECHA) · 2,105 reports · DangerH225, H302, H311, H314, H331

First aid

Warning: Piperidine is a basic irritant of skin and mucous membranes. May cause permanent injury after short exposure to small amounts. Signs and Symptoms of Piperidine Exposure: Signs and symptoms of acute exposure to piperidine may include irritation and burning of skin and mucous membranes. It may cause respiratory tract, liver, gastrointestinal tract, kidney, and CNS damage.[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…[8]
Fresh air, rest. Half-upright position. Artificial respiration may be needed. Refer for medical attention.[3]
Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention .[3]

Storage

Fireproof. Separated from strong oxidants, acids and incompatible materials. See Chemical Dangers.[3]
Fireproof. Separated from strong oxidants, acids, incompatible materials See Chemical Dangers.[4]
Store in tightly closed containers in a cool, well vented area away form oxidizers. Where possible, automatically pump liquid from drums or other storage containers to process containers. Sources of ignition such as smoking and open flames are prohibited where this chemical is handled, used, or stored. Metal containers involving the transfer of 5 gallons or more of this chemical should be grounded and bonded. Drums must be equipped with self-closing valves, pressure vacuum bungs, and flame arresters.[4]

Incompatibilities

Piperidine is a medium strong base. Reacts violently with oxidizers.[4]
Dangerous ... Can react vigorously with oxidizing materials.[4]
Incompatibilities: 1-perchloryl-piperidine[4]
Contact of dicyanofurazan, or its N-oxide (dicyanofuroxan), with ... (piperidine) ... Is instantaneously explosive.[4]

Always read the supplier’s safety data sheet before working with it.

Spectra

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]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[5]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · 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]Emergency Response Guidebook (ERG) · Public domain (US DOT) · via PubChem · retrieved 2026-10-14
[9]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
[10]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
[11]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[12]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[13]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
[14]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.

Similar structures

Tanimoto similarity on Morgan fingerprints (radius 2) with RDKit 2026.09, at least 45%.