An official website of the United States government

1,2,4-Triazole

PubChem CID
9257
Structure
1,2,4-Triazole_small.png
1,2,4-Triazole_3D_Structure.png
Molecular Formula
Synonyms
  • 1,2,4-TRIAZOLE
  • 1H-1,2,4-Triazole
  • 288-88-0
  • 4H-1,2,4-triazole
  • Pyrrodiazole
Molecular Weight
69.07 g/mol
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Dates
  • Create:
    2005-03-26
  • Modify:
    2025-01-18
Description
1H-1,2,4-triazole is a 1,2,4-triazole. It is a tautomer of a 3H-1,2,4-triazole and a 4H-1,2,4-triazole.

1 Structures

1.1 2D Structure

Chemical Structure Depiction
1,2,4-Triazole.png

1.2 3D Conformer

1.3 Crystal Structures

2 Names and Identifiers

2.1 Computed Descriptors

2.1.1 IUPAC Name

1H-1,2,4-triazole
Computed by Lexichem TK 2.7.0 (PubChem release 2021.10.14)

2.1.2 InChI

InChI=1S/C2H3N3/c1-3-2-5-4-1/h1-2H,(H,3,4,5)
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.3 InChIKey

NSPMIYGKQJPBQR-UHFFFAOYSA-N
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.4 SMILES

C1=NC=NN1
Computed by OEChem 2.3.0 (PubChem release 2024.12.12)

2.2 Molecular Formula

C2H3N3
Computed by PubChem 2.2 (PubChem release 2021.10.14)
C2H3N3

2.3 Other Identifiers

2.3.1 CAS

288-88-0

2.3.2 Deprecated CAS

1001118-18-8, 116421-29-5, 25167-73-1, 27236-77-7, 288-89-1

2.3.3 European Community (EC) Number

2.3.4 UNII

2.3.5 ChEBI ID

2.3.6 ChEMBL ID

2.3.7 DrugBank ID

2.3.8 DSSTox Substance ID

2.3.9 HMDB ID

2.3.10 ICSC Number

2.3.11 Metabolomics Workbench ID

2.3.12 Nikkaji Number

2.3.13 NSC Number

2.3.14 Wikidata

2.3.15 Wikipedia

2.4 Synonyms

2.4.1 MeSH Entry Terms

  • 1,2,4-triazole
  • 1,2,4-triazole, potassium salt

2.4.2 Depositor-Supplied Synonyms

3 Chemical and Physical Properties

3.1 Computed Properties

Property Name
Molecular Weight
Property Value
69.07 g/mol
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
XLogP3
Property Value
-0.6
Reference
Computed by XLogP3 3.0 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Donor Count
Property Value
1
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Acceptor Count
Property Value
2
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Rotatable Bond Count
Property Value
0
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Exact Mass
Property Value
69.032697108 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Monoisotopic Mass
Property Value
69.032697108 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Topological Polar Surface Area
Property Value
41.6 Ų
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Heavy Atom Count
Property Value
5
Reference
Computed by PubChem
Property Name
Formal Charge
Property Value
0
Reference
Computed by PubChem
Property Name
Complexity
Property Value
28.1
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Isotope Atom Count
Property Value
0
Reference
Computed by PubChem
Property Name
Defined Atom Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Undefined Atom Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Defined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Undefined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Covalently-Bonded Unit Count
Property Value
1
Reference
Computed by PubChem
Property Name
Compound Is Canonicalized
Property Value
Yes
Reference
Computed by PubChem (release 2021.10.14)

3.2 Experimental Properties

3.2.1 Physical Description

Other Solid; Dry Powder; Pellets or Large Crystals
Brown solid; [ICSC] White crystalline powder; [MSDSonline]
BROWN SOLID IN VARIOUS FORMS WITH CHARACTERISTIC ODOUR.

3.2.2 Color / Form

Needles from benzene/ethanol
Lide, D.R. CRC Handbook of Chemistry and Physics 88TH Edition 2007-2008. CRC Press, Taylor & Francis, Boca Raton, FL 2007, p. 3-488

3.2.3 Boiling Point

260 °C (decomposes)
Lide, D.R. CRC Handbook of Chemistry and Physics 88TH Edition 2007-2008. CRC Press, Taylor & Francis, Boca Raton, FL 2007, p. 3-488
260 °C

3.2.4 Melting Point

120-121 °C

3.2.5 Flash Point

170 °C closed cup
European Commission, ESIS; IUCLID Dataset, 1,2,4-Triazole (288-88-0) p.6 (2000 CD-ROM edition). Available from, as of September 23, 2010: https://esis.jrc.ec.europa.eu/
170 °C c.c.

3.2.6 Solubility

Soluble in water, ethanol
Lide, D.R. CRC Handbook of Chemistry and Physics 88TH Edition 2007-2008. CRC Press, Taylor & Francis, Boca Raton, FL 2007, p. 3-488
Solubility in water, g/100ml at 20 °C: 125

3.2.7 Density

640 kg/m³

3.2.8 Vapor Pressure

0.6 [mmHg]
Vapor pressure, Pa at 20 °C: 0.2

3.2.9 LogP

log Kow = -0.58
Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 4
-0.6

3.2.10 Autoignition Temperature

490 °C
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on 1,2,4-Triazole (April 2007). Available from, as of September 23, 2010: https://www.inchem.org/pages/icsc.html

3.2.11 Decomposition

When heated to decomposition it emits toxic vapors of /nitroxides/.
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 3509
The substance decomposes on heating producing toxic fumes including nitrogen oxides, ammonia fumes and hydrogen cyanide.
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on 1,2,4-Triazole (April 2007). Available from, as of September 23, 2010: https://www.inchem.org/pages/icsc.html
290 °C

3.2.12 Dissociation Constants

3.2.13 Kovats Retention Index

Standard non-polar
1116 , 1116

3.2.14 Other Experimental Properties

When heated to decomposition it emits toxic vapors of NOx
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. V3: 2508

3.3 SpringerMaterials Properties

3.4 Chemical Classes

Nitrogen Compounds -> Triazoles

3.4.1 Drugs

Pharmaceuticals -> Listed in ZINC15
S55 | ZINC15PHARMA | Pharmaceuticals from ZINC15 | DOI:10.5281/zenodo.3247749

3.4.2 Pesticides

Environmental transformation -> Pesticide transformation products (metabolite, successor)
S60 | SWISSPEST19 | Swiss Pesticides and Metabolites from Kiefer et al 2019 | DOI:10.5281/zenodo.3544759
Pesticide (1,2,4-Triazole) -> USDA PDB
Pesticide degradation product

4 Spectral Information

4.1 1D NMR Spectra

1 of 2
1D NMR Spectra
2 of 2
1D NMR Spectra

4.1.1 1H NMR Spectra

1 of 2
Instrument Name
Varian A-60
Copyright
Copyright © 2009-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail
2 of 2
Instrument Name
Varian A-60
Copyright
Copyright © 2009-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail

4.1.2 13C NMR Spectra

1 of 2
Source of Sample
Fluka AG, Buchs, Switzerland
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail
2 of 2
Source of Sample
Tokyo Kasei Kogyo Company, Ltd., Tokyo, Japan
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail

4.1.3 15N NMR Spectra

1 of 2
Copyright
Copyright © 2016-2024 W. Robien, Inst. of Org. Chem., Univ. of Vienna. All Rights Reserved.
Thumbnail
Thumbnail
2 of 2
Copyright
Copyright © 2016-2024 W. Robien, Inst. of Org. Chem., Univ. of Vienna. All Rights Reserved.
Thumbnail
Thumbnail

4.2 Mass Spectrometry

4.2.1 GC-MS

1 of 4
View All
NIST Number
230199
Library
Main library
Total Peaks
24
m/z Top Peak
69
m/z 2nd Highest
42
m/z 3rd Highest
28
Thumbnail
Thumbnail
2 of 4
View All
NIST Number
238
Library
Replicate library
Total Peaks
12
m/z Top Peak
69
m/z 2nd Highest
42
m/z 3rd Highest
28
Thumbnail
Thumbnail

4.2.2 LC-MS

1 of 2
Authors
Nikiforos Alygizakis, Katerina Galani, Nikolaos Thomaidis, University of Athens
Instrument
Bruker maXis Impact
Instrument Type
LC-ESI-QTOF
MS Level
MS2
Ionization Mode
POSITIVE
Ionization
ESI
Collision Energy
Ramp 14.4-21.6 eV
Fragmentation Mode
CID
Column Name
Acclaim RSLC C18 2.2um, 2.1x100mm, Thermo
Retention Time
1.564 min
Precursor m/z
70.04
Precursor Adduct
[M+H]+
Top 5 Peaks
70.0391 999
Thumbnail
Thumbnail
License
CC BY
2 of 2
MoNA ID
MS Category
Experimental
MS Type
LC-MS
MS Level
MS2
Precursor Type
[M+H]+
Precursor m/z
70.04
Instrument
Bruker maXis Impact
Instrument Type
LC-ESI-QTOF
Ionization
ESI
Ionization Mode
positive
Collision Energy
Ramp 14.4-21.6 eV
Retention Time
1.564 min
Top 5 Peaks
70.0391 100
Thumbnail
Thumbnail
License
CC BY

4.2.3 Other MS

1 of 5
View All
Authors
EPA CCTE and Agilent Technologies
Instrument Type
ESI-QTOF
MS Level
MS2
Ionization Mode
NEGATIVE
Ionization
ESI
Collision Energy
20
Precursor m/z
68.02542067
Precursor Adduct
[M-H]-
Top 5 Peaks

68.025421 999

41.014522 352

66.009771 85

40.019273 50

40.006697 31

Thumbnail
Thumbnail
License
CC BY
2 of 5
View All
Authors
EPA CCTE and Agilent Technologies
Instrument Type
ESI-QTOF
MS Level
MS2
Ionization Mode
NEGATIVE
Ionization
ESI
Collision Energy
40
Precursor m/z
68.02542067
Precursor Adduct
[M-H]-
Top 5 Peaks

41.014522 999

40.006697 548

68.025421 293

66.009771 278

40.019273 132

Thumbnail
Thumbnail
License
CC BY

4.3 IR Spectra

4.3.1 FTIR Spectra

1 of 2
Instrument Name
Bruker IFS 85
Technique
KBr-Pellet
Copyright
Copyright © 1989, 1990-2024 Wiley-VCH Verlag GmbH & Co. KGaA. All Rights Reserved.
Thumbnail
Thumbnail
2 of 2
Technique
KBr pellet
Source of Sample
Ega
Copyright
Copyright © 1989, 1990-2024 Wiley-VCH Verlag GmbH & Co. KGaA. All Rights Reserved.
Thumbnail
Thumbnail

4.3.2 ATR-IR Spectra

1 of 2
Instrument Name
Bruker Tensor 27 FT-IR
Technique
ATR-Neat (DuraSamplIR II)
Source of Spectrum
Bio-Rad Laboratories, Inc.
Source of Sample
Spectrochem Pvt. Ltd.
Catalog Number
120249
Copyright
Copyright © 2014-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail
2 of 2
Source of Sample
Aldrich
Catalog Number
T46108
Copyright
Copyright © 2018-2024 Sigma-Aldrich Co. LLC. - Database Compilation Copyright © 2018-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail

4.3.3 Vapor Phase IR Spectra

1 of 2
Instrument Name
DIGILAB FTS-14
Technique
Vapor Phase
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail
2 of 2
Source of Spectrum
Sigma-Aldrich Co. LLC.
Source of Sample
Sigma-Aldrich Co. LLC.
Catalog Number
T46108
Copyright
Copyright © 2021-2024 Sigma-Aldrich Co. LLC. - Database Compilation Copyright © 2021 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail

4.4 Raman Spectra

1 of 2
Instrument Name
Bruker MultiRAM Stand Alone FT-Raman Spectrometer
Technique
FT-Raman
Source of Spectrum
Bio-Rad Laboratories
Source of Sample
Spectrochem Pvt. Ltd., India
Catalog Number
120249
Copyright
Copyright © 2014-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail
2 of 2
Technique
FT-Raman
Source of Spectrum
Forensic Spectral Research
Source of Sample
Acros Organics, Janssen Chimica
Catalog Number
123470250
Lot Number
A009644901
Copyright
Copyright © 2015-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail

6 Chemical Vendors

7 Agrochemical Information

7.1 Agrochemical Category

Metabolite

7.2 Agrochemical Transformations

1,2,4 triazole is a known environmental transformation product of Paclobutrazol, Triadimenol, Bitertanol, Difenoconazole, Cyproconazole, Epoxiconazole, Fluquinconazole, Fenbuconazole, Penconazole, Tebuconazole, and Prothioconazole.

1,2,4-triazole is a known environmental transformation product of Propiconazole and Hexaconazole.

S60 | SWISSPEST19 | Swiss Pesticides and Metabolites from Kiefer et al 2019 | DOI:10.5281/zenodo.3544759

7.3 USDA Pesticide Data Program

8 Pharmacology and Biochemistry

8.1 Absorption, Distribution and Excretion

After a single oral administration of 1 mg/kg bw (test substance (14)C-labeled) to male rats (strain not given), approx 100% of the (14)C activity was absorbed from the digestive tract.
European Commission, ESIS; IUCLID Dataset, 1,2,4-Triazole (288-88-0) p.17 (2000 CD-ROM edition). Available from, as of September 23, 2010: https://esis.jrc.ec.europa.eu/
8 hr after a single iv administration of 1 mg/kg bw (test substance (14)C-labeled) to male rats (strain not given), approx 50% of the applied radioactivity was detectable in the body of the animals (gastrointestinal tract not considered). 3 days after the application approx 1.5% of the applied activity could be found, and after 6 days the (14)C-activity was no longer measurable (detection limit 0.3%).
European Commission, ESIS; IUCLID Dataset, 1,2,4-Triazole (288-88-0) p.17 (2000 CD-ROM edition). Available from, as of September 23, 2010: https://esis.jrc.ec.europa.eu/
Following a single oral or iv administration of 1 mg/kg bw (test substance (14)C-labeled) to male rats (strain not given), approx. 0.1% of the (14)C-activity was exhaled within 30 hr.
European Commission, ESIS; IUCLID Dataset, 1,2,4-Triazole (288-88-0) p.17 (2000 CD-ROM edition). Available from, as of September 23, 2010: https://esis.jrc.ec.europa.eu/
1H-1,2,4-Triazole (14)C-labeled was administered to male rats orally (dose: 1 mg/kg bw) or iv (doses: 0.1, 1, 10, 100 mg/kg bw). Within 48 hr after the single application 92-94% of the (14)C-activity was excreted with the urine and 3-5% with the feces, regardless whether the substance was applied orally or iv.
European Commission, ESIS; IUCLID Dataset, 1,2,4-Triazole (288-88-0) p.17 (2000 CD-ROM edition). Available from, as of September 23, 2010: https://esis.jrc.ec.europa.eu/
For more Absorption, Distribution and Excretion (Complete) data for 1H-1,2,4-Triazole (6 total), please visit the HSDB record page.

8.2 Transformations

9 Use and Manufacturing

9.1 Uses

EPA CPDat Chemical and Product Categories
The Chemical and Products Database, a resource for exposure-relevant data on chemicals in consumer products, Scientific Data, volume 5, Article number: 180125 (2018), DOI:10.1038/sdata.2018.125
Sources/Uses
Used in organic synthesis; [IUCLID]
Intermediate
Meister, R.T., Sine, C; Crop Protection Handbook Volume 94. Meister Media Worldwide, Willoughby, OH 2008, p. D 438

9.1.1 Use Classification

Environmental transformation -> Pesticide transformation products (metabolite, successor)
S60 | SWISSPEST19 | Swiss Pesticides and Metabolites from Kiefer et al 2019 | DOI:10.5281/zenodo.3544759

9.1.2 Industry Uses

  • Intermediate
  • Adhesives and sealant chemicals
  • Intermediates

9.1.3 Consumer Uses

Adhesives and sealant chemicals

9.2 Methods of Manufacturing

1,2,4-Triazole is made by reaction between hydrazine and formamide. Distillation.
European Commission, ESIS; IUCLID Dataset, 1,2,4-Triazole (288-88-0) p.3 (2000 CD-ROM edition). Available from, as of September 23, 2010: https://esis.jrc.ec.europa.eu/

9.3 U.S. Production

Aggregated Product Volume

2019: 1,000,000 - <10,000,000 lb

2018: 1,000,000 lb - <20,000,000 lb

2017: 1,000,000 lb - <20,000,000 lb

2016: 1,000,000 lb - <20,000,000 lb

1H-1,2,4-Triazole is listed as a High Production Volume (HPV) chemical (65FR81686). Chemicals listed as HPV were produced in or imported into the U.S. in >1 million pounds in 1990 and/or 1994. The HPV list is based on the 1990 Inventory Update Rule. (IUR) (40 CFR part 710 subpart B; 51FR21438).
EPA/Office of Pollution Prevention and Toxics; High Production Volume (HPV) Challenge Program. 1H-1,2,4-Triazole (288-88-0). Available from, as of October 12, 2010: https://www.epa.gov/hpv/pubs/general/opptsrch.htm
Production volumes for non-confidential chemicals reported under the Inventory Update Rule.
Year
1986
Production Range (pounds)
>500 thousand - 1 million
Year
1990
Production Range (pounds)
>1 million - 10 million
Year
1994
Production Range (pounds)
>10 thousand - 500 thousand
Year
1998
Production Range (pounds)
>1 million - 10 million
Year
2002
Production Range (pounds)
>1 million - 10 million
US EPA; Non-confidential Production Volume Information Submitted by Companies for Chemicals Under the 1986-2002 Inventory Update Rule (IUR). 1H-1,2,4-Triazole (288-88-0). Available from, as of October 12, 2010: https://www.epa.gov/oppt/iur/tools/data/2002-vol.html
Production volume for non-confidential chemicals reported under the 2006 Inventory Update Rule. Chemical: 1H-1,2,4-Triazole. Aggregated National Production Volume: 1 to < 10 million lbs.
US EPA; Non-Confidential 2006 Inventory Update Reporting. National Chemical Information. 1H-1,2,4-Triazole (288-88-0). Available from, as of October 14, 2010: https://cfpub.epa.gov/iursearch/index.cfm?s=chem&err=t

9.4 General Manufacturing Information

Industry Processing Sectors
  • Adhesive Manufacturing
  • Pesticide, Fertilizer, and Other Agricultural Chemical Manufacturing
EPA TSCA Commercial Activity Status
1H-1,2,4-Triazole: ACTIVE

10 Safety and Hazards

10.1 Hazards Identification

10.1.1 GHS Classification

1 of 5
View All
Pictogram(s)
Irritant
Health Hazard
Signal
Danger
GHS Hazard Statements

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

H319 (99.8%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H360FD (37.6%): May damage fertility; May damage the unborn child [Danger Reproductive toxicity]

H361 (51.3%): Suspected of damaging fertility or the unborn child [Warning Reproductive toxicity]

H361d (10.8%): Suspected of damaging the unborn child [Warning Reproductive toxicity]

H412 (11%): Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

Precautionary Statement Codes

P203, P264, P264+P265, P270, P273, P280, P301+P317, P305+P351+P338, P318, P330, P337+P317, P405, and P501

(The corresponding statement to each P-code can be found at the GHS Classification page.)

ECHA C&L Notifications Summary

Aggregated GHS information provided per 511 reports by companies from 22 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown.

10.1.2 Hazard Classes and Categories

Acute Tox. 4 (100%)

Eye Irrit. 2 (99.8%)

Repr. 1B (37.6%)

Repr. 2 (51.3%)

Repr. 2 (10.8%)

Aquatic Chronic 3 (11%)

Acute toxicity - category 4

Eye irritation - category 2

Reproductive toxicity - category 1B

10.1.3 Fire Hazards

Combustible. Gives off irritating or toxic fumes (or gases) in a fire. Finely dispersed particles form explosive mixtures in air.

10.1.4 Hazards Summary

An eye irritant; Can be absorbed through skin; Animal tests show that this substance possibly causes toxicity to human reproduction or development. [ICSC] An eye irritant; [eChemPortal: ERMA; ESIS] An irritant; [MSDSonline]

10.1.5 Fire Potential

Combustible
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on 1,2,4-Triazole (April 2007). Available from, as of September 23, 2010: https://www.inchem.org/pages/icsc.html

10.1.6 Skin, Eye, and Respiratory Irritations

Causes respiratory tract irritation, skin irritation. and eye irritation.
Sigma-Aldrich; Material Safety Data Sheet for 1,2,4-Triazole. Product Number T46108. Version 3 (December 30, 2008). Available from, as of October 15, 2010: https://www.sigmaaldrich.com/safety-center/msds-search.html
A skin and eye irritant.
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 3509

10.2 Safety and Hazard Properties

10.2.1 Physical Dangers

Dust explosion possible if in powder or granular form, mixed with air.

10.2.2 Explosive Limits and Potential

Finely dispersed particles form explosive mixtures in air.
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on 1,2,4-Triazole (April 2007). Available from, as of September 23, 2010: https://www.inchem.org/pages/icsc.html
May explode on heating.
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on 1,2,4-Triazole (April 2007). Available from, as of September 23, 2010: https://www.inchem.org/pages/icsc.html

10.3 First Aid Measures

Inhalation First Aid
Fresh air, rest.
Skin First Aid
Remove contaminated clothes. Remove contaminated clothes. Rinse skin with plenty of water or shower.
Eye First Aid
First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.
Ingestion First Aid
Rinse mouth. Give one or two glasses of water to drink. Refer for medical attention .

10.4 Fire Fighting

Use water spray, powder, foam, carbon dioxide.

10.4.1 Fire Fighting Procedures

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide. Special protective equipment for fire-fighters: Wear self contained breathing apparatus for fire fighting if necessary.
Sigma-Aldrich; Material Safety Data Sheet for 1,2,4-Triazole. Product Number T46108. Version 3 (December 30, 2008). Available from, as of October 15, 2010: https://www.sigmaaldrich.com/safety-center/msds-search.html
Powder, water spray, foam, carbon dioxide.
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on 1,2,4-Triazole (April 2007). Available from, as of September 23, 2010: https://www.inchem.org/pages/icsc.html

10.5 Accidental Release Measures

10.5.1 Spillage Disposal

Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Sweep spilled substance into covered sealable containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.

10.5.2 Cleanup Methods

Accidental Release Measures. Personal precautions: Use personal protective equipment. Avoid dust formation. Avoid breathing dust. Ensure adequate ventilation. Environmental precautions: Do not let product enter drains. Methods for cleaning up: Pick up and arrange disposal without creating dust. Keep in suitable, closed containers for disposal.
Sigma-Aldrich; Material Safety Data Sheet for 1,2,4-Triazole. Product Number T46108. Version 3 (December 30, 2008). Available from, as of October 15, 2010: https://www.sigmaaldrich.com/safety-center/msds-search.html
Do NOT let this chemical enter the environment. Sweep spilled substance into sealable containers; if appropriate, moisten first to prevent dusting. Carefully collect remainder, then remove to safe place.
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on 1,2,4-Triazole (April 2007). Available from, as of September 23, 2010: https://www.inchem.org/pages/icsc.html

10.5.3 Disposal Methods

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.
Observe all federal, state, and local environmental regulations. Contact a licensed professional waste disposal service to dispose of this material.
Sigma-Aldrich; Material Safety Data Sheet for 1,2,4-Triazole. Product Number T46108. Version 3 (December 30, 2008). Available from, as of October 15, 2010: https://www.sigmaaldrich.com/safety-center/msds-search.html

10.5.4 Preventive Measures

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.
Handle with gloves. Choose body protection according to the amount and concentration of the dangerous substance at the work place.
Sigma-Aldrich; Material Safety Data Sheet for 1,2,4-Triazole. Product Number T46108. Version 3 (December 30, 2008). Available from, as of October 15, 2010: https://www.sigmaaldrich.com/safety-center/msds-search.html
Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.
Sigma-Aldrich; Material Safety Data Sheet for 1,2,4-Triazole. Product Number T46108. Version 3 (December 30, 2008). Available from, as of October 15, 2010: https://www.sigmaaldrich.com/safety-center/msds-search.html
If inhaled, move person into fresh air. If not breathing give artificial respiration Consult a physician. In case of skin contact, wash off with soap and plenty of water. Consult a physician. In case of eye contact, rinse thoroughly with plenty of water for at least 15 minutes and consult a physician. If swallowed, never give anything by mouth to an unconscious person. Rinse mouth with water. Consult a physician.
Sigma-Aldrich; Material Safety Data Sheet for 1,2,4-Triazole. Product Number T46108. Version 3 (December 30, 2008). Available from, as of October 15, 2010: https://www.sigmaaldrich.com/safety-center/msds-search.html
Prevent deposition of dust; closed system, dust explosion-proof electrical equipment and lighting.
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on 1,2,4-Triazole (April 2007). Available from, as of September 23, 2010: https://www.inchem.org/pages/icsc.html

10.6 Handling and Storage

10.6.1 Safe Storage

Separated from strong oxidants and strong acids. Store in an area without drain or sewer access.

10.6.2 Storage Conditions

Keep container tightly closed in a dry and well-ventilated place.
Sigma-Aldrich; Material Safety Data Sheet for 1,2,4-Triazole. Product Number T46108. Version 3 (December 30, 2008). Available from, as of October 15, 2010: https://www.sigmaaldrich.com/safety-center/msds-search.html
Separated from strong oxidants, and strong acids. Store in an area without drain or sewer access.
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on 1,2,4-Triazole (April 2007). Available from, as of September 23, 2010: https://www.inchem.org/pages/icsc.html

10.7 Exposure Control and Personal Protection

10.7.1 Inhalation Risk

A harmful concentration of airborne particles can be reached quickly when dispersed.

10.7.2 Effects of Short Term Exposure

The substance is irritating to the eyes.

10.7.3 Effects of Long Term Exposure

Animal tests show that this substance possibly causes toxicity to human reproduction or development.

10.7.4 Personal Protective Equipment (PPE)

Respiratory protection: Where risk assessment shows air-purifying respirators are appropriate use a dust mask type N95 (US) or type P1 (EN 143) respirator. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Sigma-Aldrich; Material Safety Data Sheet for 1,2,4-Triazole. Product Number T46108. Version 3 (December 30, 2008). Available from, as of October 15, 2010: https://www.sigmaaldrich.com/safety-center/msds-search.html
Eye protection: Safety glasses
Sigma-Aldrich; Material Safety Data Sheet for 1,2,4-Triazole. Product Number T46108. Version 3 (December 30, 2008). Available from, as of October 15, 2010: https://www.sigmaaldrich.com/safety-center/msds-search.html
Personal protection: particulate filter adapted to the airborne concentration of the substance.
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on 1,2,4-Triazole (April 2007). Available from, as of September 23, 2010: https://www.inchem.org/pages/icsc.html
Protective gloves. Safety goggles.
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on 1,2,4-Triazole (April 2007). Available from, as of September 23, 2010: https://www.inchem.org/pages/icsc.html

10.7.5 Preventions

Fire Prevention
NO open flames. Closed system, dust explosion-proof electrical equipment and lighting. Prevent deposition of dust.
Exposure Prevention
See EFFECTS OF LONG-TERM OR REPEATED EXPOSURE. PREVENT DISPERSION OF DUST! AVOID ALL CONTACT! IN ALL CASES CONSULT A DOCTOR!
Inhalation Prevention
Use local exhaust or breathing protection.
Skin Prevention
Protective gloves.
Eye Prevention
Wear safety goggles.
Ingestion Prevention
Do not eat, drink, or smoke during work.

10.8 Stability and Reactivity

10.8.1 Hazardous Reactivities and Incompatibilities

Reacts with strong acids and strong oxidants.
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on 1,2,4-Triazole (April 2007). Available from, as of September 23, 2010: https://www.inchem.org/pages/icsc.html

10.9 Transport Information

10.9.1 EC Classification

Symbol: Xn; R: 22-36-63; S: (2)-36/37

10.10 Regulatory Information

The Australian Inventory of Industrial Chemicals
California Safe Cosmetics Program (CSCP) Reportable Ingredient

Hazard Traits - Reproductive Toxicity

Authoritative List - EC Annex VI CMRs - Cat. 1B

Report - if used as a fragrance or flavor ingredient

REACH Registered Substance
New Zealand EPA Inventory of Chemical Status
1,2,4-Triazole: Does not have an individual approval but may be used under an appropriate group standard

10.11 Other Safety Information

Chemical Assessment
IMAP assessments - 1H-1,2,4-Triazole: Human health tier II assessment

10.11.1 Toxic Combustion Products

Gives off irritating or toxic fumes (or gases) in a fire.
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on 1,2,4-Triazole (April 2007). Available from, as of September 23, 2010: https://www.inchem.org/pages/icsc.html

10.11.2 Special Reports

European Commission, ESIS; IUCLID Dataset, 1,2,4-Triazole (288-88-0) (2000 CD-ROM edition) contains information on use, toxicology, and environmental effects of this chemical as supplied to the European Union by industry.[Available from, as of September 23, 2010: http://esis.jrc.ec.europa.eu/]

11 Toxicity

11.1 Toxicological Information

11.1.1 RAIS Toxicity Values

Oral Acute Reference Dose (RfDoa)(mg/kg-day)
0.03
Oral Acute Reference Dose Reference
OPP
Oral Chronic Reference Dose (RfDoc) (mg/kg-day)
0.005
Oral Chronic Reference Dose Reference
OPP

11.1.2 EPA Human Health Benchmarks for Pesticides

Chemical Substance
Acute or One Day PAD (RfD) [mg/kg/day]
0.03
Acute or One Day HHBPs [ppb]
200
Acute HHBP Sensitive Lifestage/Population
Children
Chronic or One Day PAD (RfD) [mg/kg/day]
0.005
Chronic or One Day HHBPs [ppb]
30
Chronic HHBP Sensitive Lifestage/Population
General Population

11.1.3 USGS Health-Based Screening Levels for Evaluating Water-Quality

Chemical
1H-1,2,4-Triazole
USGS Parameter Code
68498
Chemical Classes
Pesticide degradation product
Chronic Noncancer HHBP (Human Health Benchmarks for Pesticides)[μg/L]
30
Benchmark Remarks
Listed as 1,2,4-Triazole
Reference
Smith, C.D. and Nowell, L.H., 2024. Health-Based Screening Levels for evaluating water-quality data (3rd ed.). DOI:10.5066/F71C1TWP

11.1.4 Exposure Routes

The substance can be absorbed into the body in hazardous amounts by ingestion. The substance can be absorbed into the body by inhalation and through the skin.

11.1.5 Symptoms

Eye Exposure
Redness. Pain.

11.1.6 Adverse Effects

Reproductive Toxin - A chemical that is toxic to the reproductive system, including defects in the progeny and injury to male or female reproductive function. Reproductive toxicity includes developmental effects. See Guidelines for Reproductive Toxicity Risk Assessment.

11.1.7 Acute Effects

11.1.8 Antidote and Emergency Treatment

/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3Rd edition, Elsevier Mosby, St. Louis, MO 2005, p. 160
/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3Rd edition, Elsevier Mosby, St. Louis, MO 2005, p. 160
/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3Rd edition, Elsevier Mosby, St. Louis, MO 2005, p. 160-1

11.1.9 Human Toxicity Excerpts

/SIGNS AND SYMPTOMS/ May be harmful if inhaled. Causes respiratory tract irritation. May be harmful if absorbed through skin. Causes skin irritation. Causes eye irritation. Harmful if swallowed.
Sigma-Aldrich; Material Safety Data Sheet for 1,2,4-Triazole. Product Number T46108. Version 3 (December 30, 2008). Available from, as of October 15, 2010: https://www.sigmaaldrich.com/safety-center/msds-search.html
/SIGNS AND SYMPTOMS/ Effects of short-term exposure: The substance is irritating to the eyes.
International Program on Chemical Safety/Commission of the European Communities; International Chemical Safety Card on 1,2,4-Triazole (April 2007). Available from, as of September 23, 2010: https://www.inchem.org/pages/icsc.html

11.1.10 Non-Human Toxicity Excerpts

/LABORATORY ANIMALS: Acute Exposure/ Skin irritation test: rabbits, exposure time 24 hr, ear, dose: approx 500 mg/animal, semi-occlusive, observation period: 7 days. Result: non-irritating.
European Commission, ESIS; IUCLID Dataset, 1,2,4-Triazole (288-88-0) p.13 (2000 CD-ROM edition). Available from, as of September 23, 2010: https://esis.jrc.ec.europa.eu/
/LABORATORY ANIMALS: Acute Exposure/ Eye irritation test: rabbits, dose approx 50 mg/animal, observation period: 7 days. Result: highly irritating.
European Commission, ESIS; IUCLID Dataset, 1,2,4-Triazole (288-88-0) p.14 (2000 CD-ROM edition). Available from, as of September 23, 2010: https://esis.jrc.ec.europa.eu/
/LABORATORY ANIMALS: Acute Exposure/ In an inhalation experiment rats and mice (strains not given) were exposed to 1H-1,2,4-triazole for 4 or 6 hr (test atmosphere saturated with the substance, whole-body exposure). Following the exposure period the animals were observed for 14 days. No signs of toxicity occurred.
European Commission, ESIS; IUCLID Dataset, 1,2,4-Triazole (288-88-0) p.16 (2000 CD-ROM edition). Available from, as of September 23, 2010: https://esis.jrc.ec.europa.eu/
/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ Male and female Wistar rats were fed 1H-1,2,4-triazole in their feed for 13 weeks, dosage: 100, 500, or 2500 ppm (approx 7, 33, or 167 mg/kg bw/day). A control group received untreated diet. Results: no indications of treatment-induced organ alterations (with the exception of liver findings in the 2500 ppm group). 2500 ppm (approx 167 mg/kg bw/day): temporarily reduced food consumption and lower body weights, temporary slight convulstions in individuals, lower hemoglobin, hematocrit, MCV /mean corpuscular volume/ and MCH /mean corpuscular hemoglobin/ values in the male rats, slight to moderate fat accumulation in liver parenchyma cells in 3/15 males.
European Commission, ESIS; IUCLID Dataset, 1,2,4-Triazole (288-88-0) p.14 (2000 CD-ROM edition). Available from, as of September 23, 2010: https://esis.jrc.ec.europa.eu/
For more Non-Human Toxicity Excerpts (Complete) data for 1H-1,2,4-Triazole (8 total), please visit the HSDB record page.

11.1.11 Non-Human Toxicity Values

LD50 Rat oral 1750 mg/kg
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 3509
LD50 Rat oral 1650 mg/kg bw
European Commission, ESIS; IUCLID Dataset, 1,2,4-Triazole (288-88-0) p.12 (2000 CD-ROM edition). Available from, as of September 23, 2010: https://esis.jrc.ec.europa.eu/
LD50 Rat male dermal 4200 mg/kg bw
European Commission, ESIS; IUCLID Dataset, 1,2,4-Triazole (288-88-0) p.13 (2000 CD-ROM edition). Available from, as of September 23, 2010: https://esis.jrc.ec.europa.eu/
LD50 Rat female dermal 3129 mg/kg bw
European Commission, ESIS; IUCLID Dataset, 1,2,4-Triazole (288-88-0) p.13 (2000 CD-ROM edition). Available from, as of September 23, 2010: https://esis.jrc.ec.europa.eu/
LD50 Mouse oral 1350 mg/kg
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 3508

11.2 Ecological Information

11.2.1 EPA Ecotoxicity

Pesticide Ecotoxicity Data from EPA

11.2.2 ICSC Environmental Data

The substance is harmful to aquatic organisms. This substance does enter the environment under normal use. Great care, however, should be taken to avoid any additional release, for example through inappropriate disposal.

11.2.3 Environmental Fate / Exposure Summary

1H-1,2,4-Triazole's production and use as a chemical intermediate may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 0.6 mm Hg at 25 °C indicates 1H-1,2,4-triazole will exist solely as a vapor in the atmosphere. Vapor-phase 1H-1,2,4-triazole will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 160 days. 1H-1,2,4-Triazole contains chromophores that absorb at wavelengths >290 nm and therefore may be susceptible to direct photolysis by sunlight. If released to soil, 1H-1,2,4-triazole is expected to have very high mobility based upon an estimated Koc of 5. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 1.5X10-6 atm-cu m/mole. Biodegradation data were not available. If released into water, 1H-1,2,4-triazole is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 20 and 150 days, respectively. An estimated BCF of 3 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions. Occupational exposure to 1H-1,2,4-triazole may occur through inhalation and dermal contact with this compound at workplaces where 1H-1,2,4-triazole is produced or used. (SRC)

11.2.4 Artificial Pollution Sources

1H-1,2,4-Triazole's production and use as a chemical intermediate(1) may result in its release to the environment through various waste streams(SRC).
(1) Meister RT, Sine C; Crop Protection Handbook Volume 94. Meister Media Worldwide, Willoughby, OH p. D 438 (2008)

11.2.5 Environmental Fate

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 5(SRC), determined from a structure estimation method(2), indicates that 1H-1,2,4-triazole is expected to have very high mobility in soil(SRC). Volatilization of 1H-1,2,4-triazole from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.5X10-6 atm-cu m/mole(SRC), using a fragment constant estimation method(3). 1H-1,2,4-Triazole is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 0.6 mm Hg at 25 °C(SRC), determined from a fragment constant method(4). Biodegradation data in soil were not available(SRC, 2010).
(1) Swann RL et al; Res Rev 85: 17-28 (1983)
(2) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.0. Jan, 2009. Available from, as of Oct 21, 2010: https://www.epa.gov/oppt/exposure/pubs/episuitedl.htm
(3) Meylan WM, Howard PH; Environ Toxicol Chem 10: 1283-93 (1991)
(4) Lyman WJ; p. 31 in Environmental Exposure From Chemicals Vol I, Neely WB, Blau GE, eds, Boca Raton, FL: CRC Press (1985)
AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 5(SRC), determined from a structure estimation method(2), indicates that 1H-1,2,4-triazole is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 1.5X10-6 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 20 and 150 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 3(SRC), from its log Kow of -0.58(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). 1H-1,2,4-Triazole is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). Biodegradation data in water were not available(SRC, 2010).
(1) Swann RL et al; Res Rev 85: 17-28 (1983)
(2) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.0. Jan, 2009. Available from, as of Oct 21, 2010: https://www.epa.gov/oppt/exposure/pubs/episuitedl.htm
(3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 7-4, 7-5, 15-1 to 15-29 (1990)
(4) Meylan WM, Howard PH; Environ Toxicol Chem 10: 1283-93 (1991)
(5) Franke C et al; Chemosphere 29: 1501-14 (1994)
(6) Hansch C et al; Exploring QSAR. Hydrophobic, Electronic, and Steric Constants. ACS Prof Ref Book. Heller SR, consult. ed., Washington, DC: Amer Chem Soc p. 4(1995)
(7) Meylan WM et al; Environ Toxicol Chem 18: 664-72 (1999)
ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 1H-1,2,4-triazole, which has an estimated vapor pressure of 0.6 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 1H-1,2,4-triazole is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 160 days(SRC), calculated from its rate constant of 1.0X10-13 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). 1H-1,2,4-Triazole contains chromophores that absorb at wavelengths >290 nm(4) and therefore may be susceptible to direct photolysis by sunlight(SRC).
(1) Bidleman TF; Environ Sci Technol 22: 361-367 (1988)
(2) Lyman WJ; p. 31 in Environmental Exposure From Chemicals Vol I, Neely WB, Blau GE, eds, Boca Raton, FL: CRC Press (1985)
(3) Meylan WM, Howard PH; Chemosphere 26: 2293-99 (1993)
(4) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 8-12 (1990)

11.2.6 Environmental Abiotic Degradation

The rate constant for the vapor-phase reaction of 1H-1,2,4-triazole with photochemically-produced hydroxyl radicals has been estimated as 1.0X10-13 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 160 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 1H-1,2,4-Triazole is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2). 1H-1,2,4-Triazole contains chromophores that absorb at wavelengths >290 nm(2) and therefore may be susceptible to direct photolysis by sunlight(SRC).
(1) Meylan WM, Howard PH; Chemosphere 26: 2293-99 (1993)
(2) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 7-4, 7-5, 8-12 (1990)

11.2.7 Environmental Bioconcentration

An estimated BCF of 3 was calculated in fish for 1H-1,2,4-triazole(SRC), using a log Kow of -0.58(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).
(1) Hansch C et al; Exploring QSAR. Hydrophobic, Electronic, and Steric Constants. ACS Prof Ref Book. Heller SR, consult. ed., Washington, DC: Amer Chem Soc p. 4 (1995)
(2) Meylan WM et al; Environ Toxicol Chem 18: 664-72 (1999)
(3) Franke C et al; Chemosphere 29: 1501-14 (1994)

11.2.8 Soil Adsorption / Mobility

Using a structure estimation method based on molecular connectivity indices(1), the Koc of 1H-1,2,4-triazole can be estimated to be 5(SRC). According to a classification scheme(2), this estimated Koc value suggests that 1H-1,2,4-triazole is expected to have very high mobility in soil.
(1) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.0. Jan, 2009. Available from, as of Oct 21, 2010: https://www.epa.gov/oppt/exposure/pubs/episuitedl.htm
(2) Swann RL et al; Res Rev 85: 17-28 (1983)

11.2.9 Volatilization from Water / Soil

The Henry's Law constant for 1H-1,2,4-triazole is estimated as 1.5X10-6 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 1H-1,2,4-triazole is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 20 days(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 150 days(SRC). 1H-1,2,4-triazole's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). 1H-1,2,4-Triazole is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 0.6 mm Hg(SRC), determined from a fragment constant method(3).
(1) Meylan WM, Howard PH; Environ Toxicol Chem 10: 1283-93 (1991)
(2) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 15-1 to 15-29 (1990)
(3) Lyman WJ; p. 31 in Environmental Exposure From Chemicals Vol I, Neely WB, Blau GE, eds, Boca Raton, FL: CRC Press (1985)

11.2.10 Probable Routes of Human Exposure

According to the 2006 TSCA Inventory Update Report, the number of workers reasonably likely to be exposed in the industrial manufacturing, processing, and use for 1H-1,2,4-triazole is 1000 or greater persons; the data may be greatly underestimated(1).
(1) US EPA; Inventory Update Reporting (IUR). Non-confidential 2006 IUR Records by Chemical, including Manufacturing, Processing and Use Information. Washington, DC: U.S. Environmental Protection Agency. Available from, as of Oct 21, 2010: https://cfpub.epa.gov/iursearch/index.cfm
Occupational exposure to 1H-1,2,4-triazole may occur through inhalation and dermal contact with this compound at workplaces where 1H-1,2,4-triazole is produced or used. (SRC)

12 Associated Disorders and Diseases

13 Literature

13.1 Consolidated References

13.2 NLM Curated PubMed Citations

13.3 Springer Nature References

13.4 Thieme References

13.5 Wiley References

13.6 Chemical Co-Occurrences in Literature

13.7 Chemical-Gene Co-Occurrences in Literature

13.8 Chemical-Disease Co-Occurrences in Literature

14 Patents

14.1 Depositor-Supplied Patent Identifiers

14.2 WIPO PATENTSCOPE

14.3 Chemical Co-Occurrences in Patents

14.4 Chemical-Disease Co-Occurrences in Patents

14.5 Chemical-Gene Co-Occurrences in Patents

15 Interactions and Pathways

15.1 Protein Bound 3D Structures

15.1.1 Ligands from Protein Bound 3D Structures

PDBe Ligand Code
PDBe Structure Code
PDBe Conformer

15.2 Chemical-Target Interactions

16 Biological Test Results

16.1 BioAssay Results

17 Classification

17.1 MeSH Tree

17.2 ChEBI Ontology

17.3 ChemIDplus

17.4 ChEMBL Target Tree

17.5 UN GHS Classification

17.6 EPA CPDat Classification

17.7 NORMAN Suspect List Exchange Classification

17.8 EPA DSSTox Classification

17.9 EPA TSCA and CDR Classification

17.10 EPA Substance Registry Services Tree

17.11 MolGenie Organic Chemistry Ontology

18 Information Sources

  1. Australian Industrial Chemicals Introduction Scheme (AICIS)
  2. CAS Common Chemistry
    LICENSE
    The data from CAS Common Chemistry is provided under a CC-BY-NC 4.0 license, unless otherwise stated.
    https://creativecommons.org/licenses/by-nc/4.0/
  3. ChemIDplus
    ChemIDplus Chemical Information Classification
    https://pubchem.ncbi.nlm.nih.gov/source/ChemIDplus
  4. DrugBank
    LICENSE
    Creative Common's Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/legalcode)
    https://www.drugbank.ca/legal/terms_of_use
  5. DTP/NCI
    LICENSE
    Unless otherwise indicated, all text within NCI products is free of copyright and may be reused without our permission. Credit the National Cancer Institute as the source.
    https://www.cancer.gov/policies/copyright-reuse
  6. EPA Chemical Data Reporting (CDR)
    LICENSE
    The U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce these documents, or allow others to do so, for U.S. Government purposes. These documents may be freely distributed and used for non-commercial, scientific and educational purposes.
    https://www.epa.gov/web-policies-and-procedures/epa-disclaimers#copyright
  7. EPA Chemicals under the TSCA
    EPA TSCA Classification
    https://www.epa.gov/tsca-inventory
  8. EPA DSSTox
    CompTox Chemicals Dashboard Chemical Lists
    https://comptox.epa.gov/dashboard/chemical-lists/
  9. EPA Safe Drinking Water Act (SDWA)
  10. European Chemicals Agency (ECHA)
    LICENSE
    Use of the information, documents and data from the ECHA website is subject to the terms and conditions of this Legal Notice, and subject to other binding limitations provided for under applicable law, the information, documents and data made available on the ECHA website may be reproduced, distributed and/or used, totally or in part, for non-commercial purposes provided that ECHA is acknowledged as the source: "Source: European Chemicals Agency, http://echa.europa.eu/". Such acknowledgement must be included in each copy of the material. ECHA permits and encourages organisations and individuals to create links to the ECHA website under the following cumulative conditions: Links can only be made to webpages that provide a link to the Legal Notice page.
    https://echa.europa.eu/web/guest/legal-notice
  11. FDA Global Substance Registration System (GSRS)
    LICENSE
    Unless otherwise noted, the contents of the FDA website (www.fda.gov), both text and graphics, are not copyrighted. They are in the public domain and may be republished, reprinted and otherwise used freely by anyone without the need to obtain permission from FDA. Credit to the U.S. Food and Drug Administration as the source is appreciated but not required.
    https://www.fda.gov/about-fda/about-website/website-policies#linking
  12. Hazardous Substances Data Bank (HSDB)
  13. ILO-WHO International Chemical Safety Cards (ICSCs)
  14. New Zealand Environmental Protection Authority (EPA)
    LICENSE
    This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International licence.
    https://www.epa.govt.nz/about-this-site/general-copyright-statement/
  15. Risk Assessment Information System (RAIS)
    LICENSE
    This work has been sponsored by the U.S. Department of Energy (DOE), Office of Environmental Management, Oak Ridge Operations (ORO) Office through a joint collaboration between United Cleanup Oak Ridge LLC (UCOR), Oak Ridge National Laboratory (ORNL), and The University of Tennessee, Ecology and Evolutionary Biology, The Institute for Environmental Modeling (TIEM). All rights reserved.
    https://rais.ornl.gov/
  16. California Safe Cosmetics Program (CSCP) Product Database
  17. ChEBI
  18. ChEMBL
    LICENSE
    Access to the web interface of ChEMBL is made under the EBI's Terms of Use (http://www.ebi.ac.uk/Information/termsofuse.html). The ChEMBL data is made available on a Creative Commons Attribution-Share Alike 3.0 Unported License (http://creativecommons.org/licenses/by-sa/3.0/).
    http://www.ebi.ac.uk/Information/termsofuse.html
  19. NORMAN Suspect List Exchange
    LICENSE
    Data: CC-BY 4.0; Code (hosted by ECI, LCSB): Artistic-2.0
    https://creativecommons.org/licenses/by/4.0/
    1,2,4-Triazole
    NORMAN Suspect List Exchange Classification
    https://www.norman-network.com/nds/SLE/
  20. Comparative Toxicogenomics Database (CTD)
    LICENSE
    It is to be used only for research and educational purposes. Any reproduction or use for commercial purpose is prohibited without the prior express written permission of NC State University.
    http://ctdbase.org/about/legal.jsp
  21. Therapeutic Target Database (TTD)
  22. Crystallography Open Database (COD)
    LICENSE
    All data in the COD and the database itself are dedicated to the public domain and licensed under the CC0 License. Users of the data should acknowledge the original authors of the structural data.
    https://creativecommons.org/publicdomain/zero/1.0/
  23. EPA Chemical and Products Database (CPDat)
  24. Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
    LICENSE
    Copyright (c) 2022 Haz-Map(R). All rights reserved. Unless otherwise indicated, all materials from Haz-Map are copyrighted by Haz-Map(R). No part of these materials, either text or image may be used for any purpose other than for personal use. Therefore, reproduction, modification, storage in a retrieval system or retransmission, in any form or by any means, electronic, mechanical or otherwise, for reasons other than personal use, is strictly prohibited without prior written permission.
    https://haz-map.com/About
  25. EPA Pesticide Ecotoxicity Database
  26. Hazardous Chemical Information System (HCIS), Safe Work Australia
  27. NITE-CMC
    1,2,4-Triazole - FY2022 (Revised classification)
    https://www.chem-info.nite.go.jp/chem/english/ghs/22-jniosh-2040e.html
    1,2,4-triazole - FY2007 (New/original classication)
    https://www.chem-info.nite.go.jp/chem/english/ghs/07-meti-0014e.html
  28. Regulation (EC) No 1272/2008 of the European Parliament and of the Council
    LICENSE
    The copyright for the editorial content of this source, the summaries of EU legislation and the consolidated texts, which is owned by the EU, is licensed under the Creative Commons Attribution 4.0 International licence.
    https://eur-lex.europa.eu/content/legal-notice/legal-notice.html
  29. Human Metabolome Database (HMDB)
    LICENSE
    HMDB is offered to the public as a freely available resource. Use and re-distribution of the data, in whole or in part, for commercial purposes requires explicit permission of the authors and explicit acknowledgment of the source material (HMDB) and the original publication (see the HMDB citing page). We ask that users who download significant portions of the database cite the HMDB paper in any resulting publications.
    http://www.hmdb.ca/citing
  30. IUPAC Digitized pKa Dataset
  31. Japan Chemical Substance Dictionary (Nikkaji)
  32. MassBank Europe
  33. MassBank of North America (MoNA)
    LICENSE
    The content of the MoNA database is licensed under CC BY 4.0.
    https://mona.fiehnlab.ucdavis.edu/documentation/license
  34. Metabolomics Workbench
  35. NIST Mass Spectrometry Data Center
    LICENSE
    Data covered by the Standard Reference Data Act of 1968 as amended.
    https://www.nist.gov/srd/public-law
  36. SpectraBase
  37. NMRShiftDB
  38. USDA Pesticide Data Program
  39. USGS Health-Based Screening Levels for Evaluating Water-Quality Data
  40. Protein Data Bank in Europe (PDBe)
  41. RCSB Protein Data Bank (RCSB PDB)
    LICENSE
    Data files contained in the PDB archive (ftp://ftp.wwpdb.org) are free of all copyright restrictions and made fully and freely available for both non-commercial and commercial use. Users of the data should attribute the original authors of that structural data.
    https://www.rcsb.org/pages/policies
  42. Springer Nature
  43. SpringerMaterials
  44. Thieme Chemistry
    LICENSE
    The Thieme Chemistry contribution within PubChem is provided under a CC-BY-NC-ND 4.0 license, unless otherwise stated.
    https://creativecommons.org/licenses/by-nc-nd/4.0/
  45. Wikidata
  46. Wikipedia
  47. Wiley
  48. PubChem
  49. Medical Subject Headings (MeSH)
    LICENSE
    Works produced by the U.S. government are not subject to copyright protection in the United States. Any such works found on National Library of Medicine (NLM) Web sites may be freely used or reproduced without permission in the U.S.
    https://www.nlm.nih.gov/copyright.html
  50. GHS Classification (UNECE)
  51. EPA Substance Registry Services
  52. MolGenie
    MolGenie Organic Chemistry Ontology
    https://github.com/MolGenie/ontology/
  53. PATENTSCOPE (WIPO)
  54. NCBI
CONTENTS