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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HCID 75771Generated: October 23, 2026

1-Hydroxybenzotriazole

HOBT · BENZOTRIAZOL-1-OL · HBT · HYDROXYBENZOTRIAZOLE · 1-Benzotriazolol · 1H-benzo[d][1,2,3]triazol-1-ol · N-HYDROXYBENZOTRIAZOLE · HBOT

https://huagongshe.com/en/chemical/75771

1-Hydroxybenzotriazole molecular structure

Identifiers & Physical Properties

CAS No.2592-95-2
Molecular formulaC6.H5.N3.O
Average molar mass135.12 g/mol
Monoisotopic mass135.04326178 g/mol
SMILESOn1nnc2ccccc21
InChIKeyASOKPJOREAFHNY-UHFFFAOYSA-N
PubChem CID75771
ChEMBLCHEMBL1389920
ChEBICHEBI:176967
EC No.219-989-7
DTXSIDDTXSID3044627

Chemical & Physical Properties

XLogP1.2
Topological polar surface area50.9
Hydrogen bond donors1
Hydrogen bond acceptors3
Rotatable bonds0
Heavy atoms10
Formal charge0
Complexity130
Chemical classesNitrogen Compounds -> Triazoles
SpringerMaterials Properties15N nuclear magnetic resonance spectrum
Solubility8.4 [ug/mL] (The mean of the results at pH 7.4)DMSO (Slightly), Methanol (Slightly)4.201g/L at 29℃
Physical DescriptionWhite solid[Merck Index] Light yellow fine crystals with lumps[Sigma-Aldrich MSDS]
Collision Cross Section124.9 Ų [M+H]+ [CCS Type: DTBuffer gas: N2Ionization: APCI+Dataset: TOXCASTSource Identifier: DTXSID3044627]
Melting point156-159°C
Boiling point149-150 °C
Density1 g/cm3
Vapor pressure0.009Pa at 25℃
Refractive indexn20/D 1.488
Flash point95 °C
Storage conditionsInert atmosphere,2-8°C
Physical stateSolid
pKa (acidity coefficient)7.39±0.58(Predicted)
ColorWhite to off-white crystalline powder
StabilityStable, but possible risk of explosion if heated under confinement. Flammable.
LogP (partition coefficient)0.146 at 25℃
CAS DataBase Reference2592-95-2(CAS DataBase Reference)
FDA UNIIA2T929DMG4
NIST Chemistry Reference1H-benzotriazole, 1-hydroxy-(2592-95-2)
EPA Substance Registry System1H-Benzotriazole, 1-hydroxy- (2592-95-2)
GHS pictogramGHS02
Signal wordWarning
GHS hazard statementsH228
GHS precautionary statementsP210
Hazard symbolsF,Xi,T,E
Risk statements (R)11-5-36/38-36/37/38-36-20/21-61-2
Safety statements (S)16-33-7/9-26-45-53-15-36/37-35
UN transport numberUN 0508 (1-HYDROXYBENZOTRIAZOLE, ANHYDROUS, dry or wetted with less than 20 % water, by mass)
RTECS numberDM1288000
TSCA inventory statusTSCA listed
Hazard class1.3C
Customs code29339980
Toxicityrat,LDLo,oral,5gm/kg (5000mg/kg),Acute Toxicity Data. Journal of the American College of Toxicology, Part B. Vol. 1, Pg. 679, 1992.
REACH registrationsActive

Safety & Regulations

GHS classificationDangerH203: (Deleted) Explosivefire, blast or projection hazard [Danger Explosives]P210, P230, P240, P250, P280, P370+P380, P372, P373, P401, and P501 (click each P-code to see the statement)H203 (96.8%): (Deleted) ExplosiveP210, P230, P240, P250, P264+P265, P273, P280, P305+P351+P338, P337+P317, P370+P380, P372, P373, P401, and P501 (click each P-code to see the statement)
Regulatory informationStatus: Active Update: 30-11-2020 https://echa.europa.eu/registration-dossier/-/registered-dossier/192651H-Benzotriazole, 1-hydroxy-: Does not have an individual approval but may be used under an appropriate group standard
Hazards summaryA mild eye irritantCauses somnolence and weight loss in oral lethal-dose studies of rats[RTECS] May explode on heating[Merck Index] Explosion hazardAn eye irritant[Sigma-Aldrich MSDS] See 1-Hydroxybenzotriazole hydrate.
DOT Hazard Classification1-Hydroxybenzotriazole, anhydrous, dry or wetted with less than 20 percent water, by massUN0508Div 1.3 Explosives (with predominately a fire hazard) (49 eCFR § 173.50)1-Hydroxybenzotriazole, monohydrateUN3474Div 4.1 Flammable solid (49 eCFR § 173.124)
Hazard Classes and CategoriesExpl. 1.3 (96.8%)Explosive - division 1.3
Protective Action Criteria (PAC)20 [mg/m3]220 [mg/m3]1300 [mg/m3]
TSCA inventory statusTSCA listed
RTECS numberDM1288000
UN transport numberUN 0508 (1-HYDROXYBENZOTRIAZOLE, ANHYDROUS, dry or wetted with less than 20 % water, by mass)
Customs code29339980
Toxicityrat,LDLo,oral,5gm/kg (5000mg/kg),Acute Toxicity Data. Journal of the American College of Toxicology, Part B. Vol. 1, Pg. 679, 1992.
Risk statements (R)11-5-36/38-36/37/38-36-20/21-61-2
Signal wordWarning
GHS pictogramGHS02
Hazard symbolsF,Xi,T,E
Safety statements (S)16-33-7/9-26-45-53-15-36/37-35
Hazard class1.3C
GHS hazard statementsH228
REACH registrationsActive
GHS precautionary statementsP210

Applications & Uses

Uses

additive for oligonucleotide couplings and in racemization-free peptide couplings

Uses

1-Hydroxybenzotriazole (HOBT) is used in preparation method of carbon fiber/polyamide composite powder material for laser sintering.