1,2,3-BENZOTRIAZOLE

1,2,3-Benzotriazole is a fused aromatic heterocyclic compound containing a benzene ring and a five-membered triazole ring.
1,2,3-Benzotriazole functions primarily as a corrosion inhibitor, metal-surface passivator, photographic restrainer, and chemical intermediate.
1,2,3-Benzotriazole is used in metalworking fluids, cooling systems, antifreeze formulations, protective treatments, photographic processing, and specialty chemical synthesis.

CAS Number: 95-14-7
EC Number: 202-394-1
Molecular Formula: C₆H₅N₃
Molecular Weight: 119.12 g/mol

SYNONYMS

1,2,3-Benzotriazole, Benzotriazole, 1H-Benzotriazole, 1H-1,2,3-Benzotriazole, 2H-Benzotriazole, Benzo-1,2,3-triazole, Benzo[d][1,2,3]triazole, Benzotriazol, Benztriazole, Benzisotriazole, Benzene Azimide, Benzene Azimid, Azimidobenzene, Aziminobenzene, 1,2,3-Benztriazole, 1,2,3-Triazaindene, 1,2,3-Triaza-1H-indene, 2,3-Diazaindole, 1,2-Aminoazophenylene, BTA, BTAH, Benzotriazole BTA, Copper Corrosion Inhibitor BTA, Copper Passivator BTA, Copper Tarnish Inhibitor, Copper Alloy Corrosion Inhibitor, Brass Corrosion Inhibitor, Bronze Corrosion Inhibitor, Yellow Metal Corrosion Inhibitor, Azole Corrosion Inhibitor, Aromatic Triazole Inhibitor, Cooling-Water Corrosion Inhibitor, Antifreeze Corrosion Inhibitor, Metalworking-Fluid Corrosion Inhibitor, Lubricant Corrosion Inhibitor, Aircraft Deicing Corrosion Inhibitor, Dishwasher Metal-Protecting Additive, Photographic Antifoggant, Photographic Restrainer, Photographic Development Restraining Agent, Metal-Surface Passivator, Copper-Surface Treatment Agent, Triazole Chemical Intermediate, Benzotriazole Synthesis Intermediate, Benzotriazole Research Reagent, Benzotriazole Analytical Standard, High-Purity Benzotriazole, Technical-Grade Benzotriazole, Industrial Benzotriazole, CAS 95-14-7, EC 202-394-1, EINECS 202-394-1, PubChem CID 7220, C₆H₅N₃

APPLICATIONS

1,2,3-Benzotriazole serves as a highly effective corrosion inhibitor for copper surfaces exposed to aqueous electrolytes.
1,2,3-Benzotriazole adsorbs onto copper and contributes to formation of a protective copper-benzotriazole surface film.

1,2,3-Benzotriazole supports corrosion protection of brass components containing copper and zinc.
1,2,3-Benzotriazole helps reduce tarnishing, discoloration, dezincification-related surface damage, and copper dissolution under suitable conditions.

1,2,3-Benzotriazole functions in bronze-protection formulations used for industrial components and cultural-metal conservation.
1,2,3-Benzotriazole can reduce continued copper corrosion when the surface has been properly cleaned and the treatment conditions are controlled.

1,2,3-Benzotriazole contributes to closed-loop cooling-water systems containing copper heat exchangers, tubing, and fittings.
1,2,3-Benzotriazole helps limit copper-ion release while the complete water-treatment program controls scale, microbiological growth, and other metals.

1,2,3-Benzotriazole supports industrial recirculating-water systems requiring protection of copper and copper-alloy equipment.
1,2,3-Benzotriazole performance depends on pH, concentration, temperature, chloride content, dissolved oxygen, water hardness, and surface condition.

1,2,3-Benzotriazole functions in engine-coolant and antifreeze formulations containing copper, brass, or soldered components.
1,2,3-Benzotriazole can supplement carboxylate, silicate, phosphate, molybdate, or other inhibitor packages after compatibility testing.

1,2,3-Benzotriazole contributes to aircraft and runway deicing-fluid systems requiring corrosion control for exposed metal components.
1,2,3-Benzotriazole must be evaluated for glycol compatibility, low-temperature stability, environmental release, material compatibility, and aviation specifications.

1,2,3-Benzotriazole supports water-based metalworking fluids used for cutting, grinding, forming, and machining copper-containing alloys.
1,2,3-Benzotriazole helps control staining and corrosion during processing, storage, washing, and temporary shutdown periods.

1,2,3-Benzotriazole functions in soluble-oil and synthetic metalworking-fluid concentrates.
1,2,3-Benzotriazole requires compatibility testing with emulsifiers, alkalinity agents, biocides, lubricants, antifoams, and hard-water ions.

1,2,3-Benzotriazole contributes to rolling, drawing, stamping, and forming lubricants used with copper and copper-alloy parts.
1,2,3-Benzotriazole helps limit metal discoloration without independently providing the lubricity required for deformation processes.

1,2,3-Benzotriazole supports industrial lubricants and hydraulic fluids requiring temporary protection of yellow-metal components.
1,2,3-Benzotriazole must be evaluated for oil solubility, filterability, seal compatibility, oxidation stability, and additive interactions.

1,2,3-Benzotriazole functions in aqueous cleaning systems intended to clean copper, brass, bronze, or mixed-metal assemblies.
1,2,3-Benzotriazole can reduce flash corrosion after soil removal when cleaner alkalinity, surfactants, chelators, and rinsing are compatible.

1,2,3-Benzotriazole contributes to tarnish-removal and metal-polishing formulations followed by a protective passivation stage.
1,2,3-Benzotriazole should be applied to sufficiently clean surfaces because residual oxides, oils, salts, and polishing compounds can impair film formation.

1,2,3-Benzotriazole supports automatic-dishwashing formulations designed to reduce corrosion or tarnishing of susceptible metal items.
1,2,3-Benzotriazole use in household formulations requires jurisdiction-specific safety, environmental, concentration, and consumer-exposure assessment.

1,2,3-Benzotriazole functions in electrolytic metal-processing baths where copper dissolution or discoloration must be controlled.
1,2,3-Benzotriazole can influence deposition, etching, cleaning, rinsing, and subsequent coating adhesion and therefore requires process validation.

1,2,3-Benzotriazole contributes to electroplating and electroless-plating processes involving copper-containing substrates.
1,2,3-Benzotriazole can be used during selected process stages to control copper activity, although excessive adsorption can interfere with deposition.

1,2,3-Benzotriazole supports copper chemical-mechanical planarization research as a surface-passivating and dissolution-controlling additive.
1,2,3-Benzotriazole helps balance copper removal and surface protection when oxidizer, abrasive, complexant, pH, and polishing conditions are optimized.

1,2,3-Benzotriazole functions in printed-circuit-board processing where temporary copper protection is required between manufacturing stages.
1,2,3-Benzotriazole can reduce oxidation during handling and storage when subsequent soldering, plating, bonding, and cleaning remain compatible.

1,2,3-Benzotriazole contributes to temporary protection of copper wire, foil, connectors, terminals, and electrical contacts.
1,2,3-Benzotriazole treatment must be evaluated for contact resistance, solderability, adhesion, electrical reliability, and residue removal.

1,2,3-Benzotriazole supports preservation of bronze and copper-alloy sculptures, coins, archaeological objects, and decorative metalwork.
1,2,3-Benzotriazole conservation use requires professional assessment because porous corrosion products can retain chlorides and treatment residues.

1,2,3-Benzotriazole functions as a photographic restrainer and antifogging agent in selected silver-halide developer systems.
1,2,3-Benzotriazole suppresses unwanted development in unexposed regions while dosage affects image speed, contrast, density, and development time.

1,2,3-Benzotriazole contributes to photographic-processing solutions used for specialized films, papers, plates, and laboratory emulsions.
1,2,3-Benzotriazole must be dissolved and dosed uniformly because localized excess can cause uneven development or excessive image restraint.

1,2,3-Benzotriazole serves as a chemical intermediate for producing substituted benzotriazoles and functional triazole derivatives.
1,2,3-Benzotriazole can undergo alkylation, acylation, halogenation, nitration, coupling, and other controlled organic reactions.

1,2,3-Benzotriazole supports synthesis of activated acyl-transfer and peptide-coupling intermediates containing benzotriazole-derived leaving groups.
1,2,3-Benzotriazole derivatives can improve reaction selectivity or activation efficiency when the synthetic process is appropriately designed.

1,2,3-Benzotriazole functions as a starting structure for producing ultraviolet absorbers, stabilizers, dyes, pharmaceuticals, and specialty organic compounds.
1,2,3-Benzotriazole itself should not be treated as equivalent to substituted benzotriazole ultraviolet stabilizers with different structures and properties.

1,2,3-Benzotriazole serves as an analytical reference and research reagent in corrosion, electrochemistry, environmental science, and organic synthesis.
1,2,3-Benzotriazole can be evaluated through chromatography, spectroscopy, electrochemical methods, adsorption studies, and surface-analysis techniques.

DESCRIPTION

1,2,3-Benzotriazole is the simplest fused benzotriazole composed of a benzene ring joined to a 1,2,3-triazole ring.
1,2,3-Benzotriazole has the molecular formula C₆H₅N₃ and a molecular weight of approximately 119.12 g/mol.

1,2,3-Benzotriazole is identified by CAS Number 95-14-7 and EC Number 202-394-1.
1,2,3-Benzotriazole is commonly identified systematically as 1H-benzo[d][1,2,3]triazole or 1H-1,2,3-benzotriazole.

1,2,3-Benzotriazole contains three adjacent nitrogen atoms within an aromatic five-membered ring.
1,2,3-Benzotriazole displays tautomerism because the ring proton can be associated with different nitrogen positions.

1,2,3-Benzotriazole normally appears as white to light-tan crystals, flakes, needles, granules, or powder.
1,2,3-Benzotriazole is generally described as odorless or having only a weak characteristic odor.

1,2,3-Benzotriazole has a melting range commonly reported near 96–100°C.
1,2,3-Benzotriazole should not be heated excessively because decomposition and potentially hazardous nitrogen-containing fumes can occur.

1,2,3-Benzotriazole is slightly to moderately soluble in water, with reported values varying according to temperature, purity, pH, and test method.
1,2,3-Benzotriazole becomes more water compatible under alkaline conditions as deprotonated benzotriazolate species are formed.

1,2,3-Benzotriazole dissolves more readily in selected alcohols, glycols, polar organic solvents, and alkaline aqueous solutions.
1,2,3-Benzotriazole formulation behavior depends on solvent polarity, temperature, salt content, neutralization, and the presence of surfactants.

1,2,3-Benzotriazole adsorbs strongly onto copper through interactions involving the nitrogen-rich triazole ring.
1,2,3-Benzotriazole can form adsorbed molecules, copper complexes, polymeric chains, or multilayer structures depending on the copper surface and solution conditions.

1,2,3-Benzotriazole inhibits copper corrosion by reducing anodic dissolution and creating a barrier to aggressive species.
1,2,3-Benzotriazole protection is influenced by protonation state, surface coverage, copper oxidation state, chloride concentration, and pH.

1,2,3-Benzotriazole generally provides its strongest and most established corrosion-inhibition performance on copper and copper alloys.
1,2,3-Benzotriazole performance on steel, aluminum, zinc, and other metals is more formulation dependent and may require complementary inhibitors.

1,2,3-Benzotriazole can be produced through diazotization and cyclization reactions involving ortho-phenylenediamine and a nitrite source.
1,2,3-Benzotriazole manufacturing requires control of reaction temperature, acidity, residual starting materials, inorganic salts, color, and purification.

1,2,3-Benzotriazole quality is commonly controlled through assay, melting range, moisture, ash, color, solution clarity, and related-substance testing.
1,2,3-Benzotriazole technical, analytical, electronic, photographic, and corrosion-inhibitor grades are not automatically interchangeable.

1,2,3-Benzotriazole is environmentally relevant because widespread industrial and consumer use can introduce it into wastewater and surface water.
1,2,3-Benzotriazole has limited volatility, low measured bioconcentration, and comparatively slow biodegradation in many environmental screening studies.

PROPERTIES

Chemical Name: 1H-1,2,3-Benzotriazole

Chemical Class: Fused Aromatic Triazole

CAS Number: 95-14-7

EC Number: 202-394-1

Molecular Formula: C₆H₅N₃

Molecular Weight: 119.12 g/mol

Physical Form: Crystalline Solid, Flakes, Granules, or Powder

Appearance: White to Light Tan

Melting Point: Approximately 96–100°C

Water Solubility: Slight to Moderate and pH Dependent

Primary Function: Copper and Copper-Alloy Corrosion Inhibitor

Main Uses: Cooling Fluids, Antifreeze, Metalworking, Metal Protection, Photography, and Chemical Synthesis

Common Hazard Concerns: Harmful if Swallowed, Eye Irritation, Combustible Dust, and Aquatic Toxicity

Storage: Cool, Dry, Tightly Closed, and Protected from Heat, Moisture, and Oxidizing Agents

FIRST AID

Inhalation

1,2,3-Benzotriazole dust exposure should be followed by movement to fresh air and rest in a position comfortable for breathing.
1,2,3-Benzotriazole inhalation requires medical attention if coughing, throat irritation, dizziness, wheezing, or breathing difficulty persists.

Skin Contact

1,2,3-Benzotriazole contamination should be removed from the skin using soap and plenty of water.
1,2,3-Benzotriazole skin exposure requires medical advice if persistent redness, irritation, pain, rash, or another adverse response develops.

Eye Contact

1,2,3-Benzotriazole eye exposure should be rinsed immediately with clean running water for at least 15 minutes while the eyelids are held open.
1,2,3-Benzotriazole eye exposure requires contact-lens removal when easy and prompt medical attention if pain, redness, or visual disturbance continues.

Ingestion

1,2,3-Benzotriazole accidental ingestion should be followed by thorough rinsing of the mouth without inducing vomiting unless instructed by medical personnel.
1,2,3-Benzotriazole ingestion requires prompt contact with a physician or poison information center because the substance is commonly classified as harmful if swallowed.

Note to Physicians

1,2,3-Benzotriazole exposure should be treated symptomatically with appropriate supportive care.
1,2,3-Benzotriazole exposure assessment should consider amount, grade, route, symptom development, accompanying formulation ingredients, and current safety documentation.

HANDLING AND STORAGE

Handling

1,2,3-Benzotriazole should be handled using methods that minimize dust generation, skin contact, eye contact, and environmental release.
1,2,3-Benzotriazole should be kept away from food, drink, excessive heat, strong oxidizing agents, and incompatible reactive chemicals.

Ventilation

1,2,3-Benzotriazole powder-handling areas should have effective general ventilation and local dust extraction where necessary.
1,2,3-Benzotriazole respiratory protection should be used when engineering controls cannot adequately limit airborne powder or aerosol.

Storage

1,2,3-Benzotriazole should be stored in tightly closed containers within a cool, dry, and well-ventilated area.
1,2,3-Benzotriazole should be protected from humidity, excessive heat, direct sunlight, oxidizing agents, contamination, and damaged packaging.

Spill and Leak Procedures

1,2,3-Benzotriazole spills should be collected using filtered vacuum equipment or another low-dust recovery method.
1,2,3-Benzotriazole should be prevented from entering drains, soil, groundwater, or surface water, and recovered waste should be placed in labeled containers.

Handling Precautions

1,2,3-Benzotriazole handling should include chemical-resistant gloves, protective clothing, and tightly fitting safety goggles.
1,2,3-Benzotriazole processing should include dust-control assessment, suitable housekeeping, emergency eyewash access, and review of the current grade-specific Safety Data Sheet.