Urea
Athanor · official
CH4N2O · 60.056 g/mol
Also called carbamide, BUN, urea nitrogen
Names and identifiers
- IUPAC name
- urea
- Synonyms
- carbamide, BUN, urea nitrogen
+ 37 more
Carbonyldiamide, Ureophil, Carbonyldiamine, Ureaphil, Keratinamin, Urevert, Alphadrate, Aquadrate, Carbaderm, Pastaron, Urepearl, Carbonyl diamide, Carbamide resin, Ultra Mide, Varioform ii, Aqua Care, Harnstoff, Mocovina, Nutraplus, Prespersion, 75 urea, Supercel 3000, Aqua Care HP, Ureacin-10 lotion, Ureacin-40 Creme, Caswell No. 902, NCI-C02119, Antisepsis bolus, Elaqua xx, Sterile Urea, EPA Pesticide Chemical Code 085702, AI3-01202, Azodicarboxylic acid-diamide, NSC-34375, INS NO.927A, E927b, INS-927A, E-927A
- Molecular formula
- CH4N2O
- Empirical formula
- CH4N2O
- Molecular weight
- 60.056 g/mol
- Exact mass
- 60.03236
- CAS number
- 57-13-6
- PubChem CID
- 1176
- Canonical SMILES
- C(=O)(N)N
- Isomeric SMILES
- C(=O)(N)N
- InChI
- InChI=1S/CH4N2O/c2-1(3)4/h(H4,2,3,4)
- InChIKey
- XSQUKJJJFZCRTK-UHFFFAOYSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Physical properties
- Appearance
- White crystals or powder[4]
4 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source – Urea appears as solid odorless white crystals or pellets. Density 1.335 g /cc. Noncombustible. [1] CAMEO Chemicals – Dry Powder; Other Solid; Wet Solid; Large Crystals; CBI; Liquid; Large Crystals; Liquid; Large Crystals; Liquid; Other Solid; Liquid; Other Solid [2] EPA Chemical Data Reporting (CDR) – WHITE CRYSTALS WITH CHARACTERISTIC ODOUR. [3] ILO-WHO International Chemical Safety Cards (ICSCs) –shown White crystals or powder [4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997., p. 1157 - Odor
- Almost odorless[4]
2 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source – MAY GRADUALLY DEVELOP SLIGHT ODOR OF AMMONIA, ESP IN PRESENCE OF MOISTURE [4] Hazardous Substances Data Bank (HSDB)cites Osol, A. and J.E. Hoover, et al. (eds.). Remington's Pharmaceutical Sciences. 15th ed. Easton, Pennsylvania: Mack Publishing Co., 1975., p. 864 –shown Almost odorless [4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997., p. 1157 - Melting point
- 132.70 °C[4]
5 values
3 of 4 sources agree on it (most common value).
Value As written Source 135 °C 275 °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. 132.7 °Cshown 132.70 °C [4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997., p. 1157 135 °C Decomposition temp = 135 °C [4] Hazardous Substances Data Bank (HSDB)cites Environment Canada; Tech Info from Problem Spills: Urea p. 4 (1985) 132.7 to 135.0 °C 132.7-135 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs) 132.7 °C 132.7 °C [5] PAC Chemical Database, U.S. Department of Energy 4 more values were reported but failed the checks (unreadable or out of range), so they are not shown.
- Boiling point
- Reported, but no value passed the checks.
The value and why
- Decomposes (NTP, 1992) (could not be read; source [1])
- Density
- 1.335 @25 °C[5]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source – 1.34 at 68 °F (USCG, 1999) - Denser 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. –shown 1.335 @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 – Soluble (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, 5.45X10+5 mg/l @ 25 °C [4] Hazardous Substances Data Bank (HSDB)cites Yalkowsky SH; Arizona Database of Aqueous Solubilities. Univ of AZ, College of Pharmacy (1989) –shown Solubility in water: miscible [3] ILO-WHO International Chemical Safety Cards (ICSCs) - log P
- -3.00/-1.54[3]
2 values
Sources disagree; from ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative.
Value As written Source – log Kow = -2.11 [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. 3 –shown -3.00/-1.54 [3] ILO-WHO International Chemical Safety Cards (ICSCs) - pKa
- pKa = 0.10 at 21 °C (conjugate acid)[4]
- Vapor pressure
- 1.2 × 10⁻⁵ mmHg @ 25 °C[4]
- Autoignition temperature
- Reported, but no value passed the checks.
The value and why
- Not flammable (USCG, 1999) (could not be read; source [1])
- Viscosity
- 1.78 mPa-s (46% solution @ 20 °C)[4]
2 values
Only one source reports it.
Value As written Source –shown 1.78 mPa-s (46% solution @ 20 °C) [4] Hazardous Substances Data Bank (HSDB)cites Environment Canada; Tech Info from Problem Spills: Urea p. 4 (1985) – 1.90 mPa-s (saturated solution @ 20 °C) [4] Hazardous Substances Data Bank (HSDB)cites Environment Canada; Tech Info from Problem Spills: Urea p. 4 (1985) 1 more value was reported but failed the checks (unreadable or out of range), so it is not shown.
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
- 4
- Rings
- 0
- Aromatic rings
- 0
- Fraction sp³ carbons (Fsp3)
- 0
- H-bond donors
- 2
- H-bond acceptors
- 1
- Rotatable bonds
- 0
- TPSA (Ų)
- 69.1
- Formal charge
- 0
- XLogP3
- -1.4 PubChem
- Complexity
- 29 PubChem
- Stereocenters
- None
- Double-bond geometry
- None specified
- Point group
- C2 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)
Elemental analysis
- C20.00%
- H6.71%
- N46.65%
- O26.64%
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
- -0.98 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- 0.4 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 1.93 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 60.06
- log P ≤ 5 (Crippen): -0.98
- H-bond donors ≤ 5: 2
- 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
This chemical does not meet GHS hazard criteria for 96.1% (4430 of 4611) of all reports.[6]
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]
- Fresh air, rest.[3]
- Rinse and then wash skin with water and soap.[3]
- First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.[3]
Storage
- Separated from incompatible materials. See Chemical Dangers.[3]
Incompatibilities
Safety data sheets on the supplier’s page: LGC Standards, Sigma-Aldrich, MedChemexpress MCE.
Always read the supplier’s safety data sheet before working with it.
Spectra
- NMRHazardous Substances Data Bank (HSDB) · NMRShiftDB
- 1H NMRHuman Metabolome Database (HMDB) (Varian · 500 MHz · Water) · Human Metabolome Database (HMDB) (500 MHz · H2O) · Human Metabolome Database (HMDB) (JEOL · 300 MHz · acetone+DMSO+tetramethylurea) · SpectraBase (Varian A-60D)
- 13C NMRHuman Metabolome Database (HMDB) (Bruker · 125 MHz · Water) · Human Metabolome Database (HMDB) (400 MHz · H2O) · SpectraBase
- 15N NMRSpectraBase
- 17O NMRSpectraBase
- GC-MSHuman Metabolome Database (HMDB) (EI-B · positive) · Human Metabolome Database (HMDB) (GC-EI-TOF · positive) · Human Metabolome Database (HMDB) (GC-MS) · Human Metabolome Database (HMDB) (GC-EI-TOF · positive) · Human Metabolome Database (HMDB) (GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies) · Positive) · Human Metabolome Database (HMDB) (GC-MS)
- MS-MSHuman Metabolome Database (HMDB) (LC-ESI-IT · positive) · Human Metabolome Database (HMDB) (Quattro_QQQ · Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Quattro_QQQ · Positive) · Human Metabolome Database (HMDB) (Quattro_QQQ · Positive)
- LC-MSMassBank Europe (LTQ XL, Thermo Finnigan · LC-ESI-IT · POSITIVE) · MassBank of North America (MoNA) (LTQ XL, Thermo Finnigan · LC-ESI-IT · ESI) · MassBank of North America (MoNA) (Agilent 6550 iFunnel · LC-ESI-QTOF · positive) · MassBank of North America (MoNA) (Agilent 6550 iFunnel · LC-ESI-QTOF · positive)
- Other MSHazardous Substances Data Bank (HSDB) · MassBank Europe (HITACHI M-2500 · EI-B · POSITIVE) · MassBank of North America (MoNA) (ESI · positive)
- UVHazardous Substances Data Bank (HSDB)
- IRHazardous Substances Data Bank (HSDB)
- FTIRSpectraBase (KBr WAFER)
- ATR-IRSpectraBase (Bio-Rad FTS · ATR-Neat (DuraSamplIR II) ground)
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]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
- [7]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
- [8]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
- [9]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
- [10]MassBank Europe · 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
- ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
- ·Literature on PubChem
Data last updated 2026-10-14.