Pyrogallol
Athanor · official
C6H6O3 · 126.11 g/mol
IUPAC name: benzene-1,2,3-triol
Also called benzene-1,2,3-triol, pyrogallic acid, oxygen absorber
WarningHarmful if swallowed · Harmful in contact with skin · Harmful if inhaled · Suspected of causing genetic defects · Harmful to aquatic life with long lasting effectsNames and identifiers
- IUPAC name
- benzene-1,2,3-triol
- Synonyms
- benzene-1,2,3-triol, pyrogallic acid, oxygen absorber
+ 35 more
1,2,3-trihydroxybenzene, 1,2,3-benzenetriol, fourrine PG, Fouramine Brown AP, fourrine 85, Pyro, C.I. Oxidation Base 32, fouramine base ap, 1,2,3-Trihydroxybenzen, C.I. 76515, CI Oxidation Base 32, Benzene, 1,2,3-trihydroxy-, DTXSID6025983, NSC-5035, 01Y4A2QXY0, CI 76515, DTXCID905983, CHEBI:16164, acid, Pyrogallic, RefChem:6187, 201-762-9, Piral, NSC 5035, 2,3-Dihydroxyphenol, PYROGALLOL, ACS, 1,2,3-Trihydroxybenzen [Czech], 1,2,3-TRIHYDROXY-BENZENE, MFCD00002192, Pyrogallic, CHEMBL307145, NCGC00091507-01, 1,2,3-Trihydroxybenzen (CZECH), Pyrogallol acid, CAS-87-66-1, Pyrogallol [NF]
- Molecular formula
- C6H6O3
- Empirical formula
- C2H2O
- Molecular weight
- 126.11 g/mol
- Exact mass
- 126.03169
- CAS number
- 87-66-1
- PubChem CID
- 1057
- Canonical SMILES
- C1=CC(=C(C(=C1)O)O)O
- Isomeric SMILES
- C1=CC(=C(C(=C1)O)O)O
- InChI
- InChI=1S/C6H6O3/c7-4-2-1-3-5(8)6(4)9/h1-3,7-9H
- InChIKey
- WQGWDDDVZFFDIG-UHFFFAOYSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Physical properties
TemperaturePressureDensity
- Appearance
- Leaflets or needles[4]
5 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source – Pyrogallic acid is an odorless white to gray solid. Sinks and mixes with water. (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. – Dry Powder [2] EPA Chemical Data Reporting (CDR) – WHITE SOLID IN VARIOUS FORMS. TURNS GREY ON EXPOSURE TO LIGHT AND AIR. [3] ILO-WHO International Chemical Safety Cards (ICSCs) – White, lustrous crystals or plates [4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. V3: 3120 –shown Leaflets or needles [4] Hazardous Substances Data Bank (HSDB)cites Verschueren, K. Handbook of Environmental Data on Organic Chemicals. Volumes 1-2. 4th ed. John Wiley & Sons. New York, NY. 2001, p. V2: 1868 - Melting point
- 131-134 °C[3]
2 values
Sources disagree; from ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative.
Value As written Source 133 to 134 °C 271 to 273 °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. 131 to 134 °Cshown 131-134 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs) - Boiling point
- 309 °C[3]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source 309 °C 588 °F at 760 mmHg (Decomposes at 559 °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. 309 °Cshown 309 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs) 309 °C 309 °C @760 [mm Hg] [5] PAC Chemical Database, U.S. Department of Energy - Density
- 1.453 @ 4°C[5]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source – 1.45 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. – Relative density (water = 1): 1.45 [3] ILO-WHO International Chemical Safety Cards (ICSCs) –shown 1.453 @ 4°C [5] PAC Chemical Database, U.S. Department of Energy - Solubility in water
- Solubility in water, g/100ml at 20 °C: 60 (good)[3]
6 values
From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.
Value As written Source – greater than or equal to 100 mg/mL at 77 °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. – Very soluble in ethanol, diethyl ether [4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. V3: 3120 – Soluble in oxygenated solvents [4] Hazardous Substances Data Bank (HSDB)cites Ashford, R.D. Ashford's Dictionary of Industrial Chemicals. London, England: Wavelength Publications Ltd., 1994., p. 778 – Solubility in water: 6.25X10+5 mg/L at 25 °C; 4X10+5 mg/L at 13 °C [4] Hazardous Substances Data Bank (HSDB)cites Fiege H et al; Ullmann's Encyclopedia of Industrial Chemistry. 7th ed. (2008). New York, NY: John Wiley & Sons; Phenol Derivatives. Online Posting Date: June 15, 2000. – In water, 5.07X10+5 mg/L at 25 °C [4] Hazardous Substances Data Bank (HSDB)cites Yalkowsky, S.H., He, Yan., Handbook of Aqueous Solubility Data: An Extensive Compilation of Aqueous Solubility Data for Organic Compounds Extracted from the AQUASOL dATAbASE. CRC Press LLC, Boca Raton, FL. 2003., p. 260 –shown Solubility in water, g/100ml at 20 °C: 60 (good) [3] ILO-WHO International Chemical Safety Cards (ICSCs) - log P
- 0.970 (estimated)[3]
- pKa
- pKa = 9.01[4]
- Vapor pressure
- Vapor pressure, kPa at 168 °C: 1.33[3]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source 10 mmHg 10 mmHg at 333.9 °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. 9.98 mmHgshown Vapor pressure, kPa at 168 °C: 1.33 [3] ILO-WHO International Chemical Safety Cards (ICSCs) 10 mmHg 10 [mm Hg] @167.7 °C [5] PAC Chemical Database, U.S. Department of Energy
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
- 9
- Rings
- 1
- Aromatic rings
- 1
- Fraction sp³ carbons (Fsp3)
- 0
- H-bond donors
- 3
- H-bond acceptors
- 3
- Rotatable bonds
- 0
- TPSA (Ų)
- 60.7
- Formal charge
- 0
- XLogP3
- 0.5 PubChem
- Complexity
- 84 PubChem
- Stereocenters
- None
- Double-bond geometry
- None specified
- Point group
- C1 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)
Elemental analysis
- C57.14%
- H4.80%
- O38.06%
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
- 0.8 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -1.62 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 1.9 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 126.11
- log P ≤ 5 (Crippen): 0.8
- H-bond donors ≤ 5: 3
- H-bond acceptors ≤ 10: 3
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].
- Harmful or irritant
- Health hazard
- H302Harmful if swallowed
- H312Harmful in contact with skin
- H332Harmful if inhaled
- H341Suspected of causing genetic defects
- H412Harmful to aquatic life with long lasting effects
Precautionary statements: P203, P261, P264, P270, P271, P273, P280, P301+P317, P302+P352, P304+P340, P317, P318, P321, P330, P362+P364, P405, P501
View all classifications (2)
- [6] Regulation (EC) No 1272/2008 of the European Parliament and of the Council · WarningH302, H312, H332, H341, H412
- [7] European Chemicals Agency (ECHA) · 332 reports · WarningH302+H312+H332, H302, H312, H315, H319, H332, H341, H412
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. Seek medical attention if you feel unwell.[3]
- Remove contaminated clothes. Rinse skin with plenty of water or shower.[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 strong oxidants and strong bases.[3]
- (store) separated from strong oxidants, strong bases.[4]
- IN general, materials which ARE toxic AS stored OR which CAN decomp INTO toxic components...should BE stored IN A COOL, well-ventilated place, BUT OUT OF direct RAYS OF THE SUN, AWAY FROM areas OF HIGH FIRE hazard, & should BE periodically inspected... Incompatible materials should BE isolated...[4]
Incompatibilities
Safety data sheets on the supplier’s page: MP Biomedicals, CAPOT, Yuhao Chemical.
Always read the supplier’s safety data sheet before working with it.
Spectra
- NMRHazardous Substances Data Bank (HSDB) · NMRShiftDB
- 1H NMRSpectraBase (Varian A-60)
- 13C 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) · MassBank Europe (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies · GC-EI-TOF · POSITIVE) · MassBank of North America (MoNA) (GCMS-2010 Plus, Shimadzu · EI-B · positive)
- MS-MSHuman Metabolome Database (HMDB) (Negative) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Negative) · Human Metabolome Database (HMDB) (Negative)
- LC-MSMassBank Europe (Exploris 240 Orbitrap Thermo Scientific · LC-ESI-QFT · NEGATIVE) · MassBank Europe (Exploris 240 Orbitrap Thermo Scientific · LC-ESI-QFT · NEGATIVE) · MassBank Europe (Exploris 240 Orbitrap Thermo Scientific · LC-ESI-QFT · NEGATIVE) · MassBank Europe (Exploris 240 Orbitrap Thermo Scientific · LC-ESI-QFT · NEGATIVE) · MassBank Europe (Exploris 240 Orbitrap Thermo Scientific · LC-ESI-QFT · NEGATIVE) · MassBank of North America (MoNA) (Thermo Q Exactive HF · LC-ESI-QFT · negative)
- Other MSHazardous Substances Data Bank (HSDB) · MassBank Europe (GCMS-2010 Plus, Shimadzu · EI-B · POSITIVE) · MassBank Europe (waters xevo g2 TOF · ESI-TOF · POSITIVE) · MassBank Europe (waters xevo g2 TOF · ESI-TOF · POSITIVE)
- UVHazardous Substances Data Bank (HSDB)
- IRHazardous Substances Data Bank (HSDB)
- FTIRSpectraBase (Bruker IFS 85 · KBr-Pellet)
- ATR-IRSpectraBase (Bruker Tensor 27 FT-IR · ATR-Neat (DuraSamplIR II))
- Vapor Phase IRSpectraBase (DIGILAB FTS-14 · Vapor Phase)
- 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]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]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
- [9]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
- [10]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
- [11]MassBank Europe · 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
- ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
- ·Literature on PubChem
Data last updated 2026-10-14.