1,2,4-Triazol

log Kow = -0.58

-0.6

Soluble in water, ethanol

Solubility in water, g/100ml at 20 °C: 125

170 °C closed cup

170 °C c.c.

260 °C (decomposes)

260 °C

When heated to decomposition it emits toxic vapors of /nitroxides/.

The substance decomposes on heating producing toxic fumes including nitrogen oxides, ammonia fumes and hydrogen cyanide.

290 °C

0.6 [mmHg]

Vapor pressure, Pa at 20 °C: 0.2

Other Solid; Large Crystals

Brown solid; [ICSC] White crystalline powder; [MSDSonline]

BROWN SOLID IN VARIOUS FORMS WITH CHARACTERISTIC ODOUR.

Danger

H302: Harmful if swallowed [Warning Acute toxicity, oral]；H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]；H360FD: May damage fertility; May damage the unborn child [Danger Reproductive toxicity]

P203, P264, P264+P265, P270, P280, P301+P317, P305+P351+P338, P318, P330, P337+P317, P405, and P501 (click each P-code to see the statement)

Danger

Chemical: 1H-1,2,4-Triazole

Hazard Traits - Reproductive Toxicity；Authoritative List - EC Annex VI CMRs - Cat. 1B；Report - if used as a fragrance or flavor ingredient

Regulation (EC) No 1107/2009 (amended)

1H-1,2,4-Triazole is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of 1H-1,2,4-Triazole are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

1,2,4-Triazole is listed in the dataset of EPA Human Health Benchmarks for Pesticides under the Safe Drinking Water Act (40 eCFR 141)

Status: Active Update: 26-04-2022 https://echa.europa.eu/registration-dossier/-/registered-dossier/13353

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/]

Acute Tox. 4 (100%)；Eye Irrit. 2 (99.8%)；Repr. 1B (46.9%)；Repr. 2 (42.3%)；Repr. 2 (10.4%)；Aquatic Chronic 3 (10.6%)

Acute toxicity - category 4；Eye irritation - category 2；Reproductive toxicity - category 1B

Reproductive toxicity - Category 1B；Hazardous to the aquatic environment (Acute) - Category 3；Hazardous to the aquatic environment (Long-term) - Category 3

Acute toxicity (Oral) - Category 4；Acute toxicity (Dermal) - Category 5；Serious eye damage/eye irritation - Category 2；Reproductive toxicity - Category 2

Repr. 1B；Acute Tox. 4；Eye Irrit. 2

Finely dispersed particles form explosive mixtures in air.

May explode on heating.

Fresh air, rest.

Remove contaminated clothes. Remove contaminated clothes. Rinse skin with plenty of water or shower.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Give one or two glasses of water to drink. Refer for medical attention .

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.

Powder, water spray, foam, carbon dioxide.

Keep container tightly closed in a dry and well-ventilated place.

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

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.

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.

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.

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.

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.

Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.

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.

Prevent deposition of dust; closed system, dust explosion-proof electrical equipment and lighting.

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).

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).

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).

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.

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.

/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.

/SIGNS AND SYMPTOMS/ Effects of short-term exposure: The substance is irritating to the eyes.

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).

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).

/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.

/LABORATORY ANIMALS: Acute Exposure/ Eye irritation test: rabbits, dose approx 50 mg/animal, observation period: 7 days. Result: highly irritating.

/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.

/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.

For more Non-Human Toxicity Excerpts (Complete) data for 1H-1,2,4-Triazole (8 total), please visit the HSDB record page.

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).

Chemical: 1H-1,2,4-Triazole

Hazard Traits - Reproductive Toxicity；Authoritative List - EC Annex VI CMRs - Cat. 1B；Report - if used as a fragrance or flavor ingredient

Regulation (EC) No 1107/2009 (amended)

1H-1,2,4-Triazole is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of 1H-1,2,4-Triazole are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

1,2,4-Triazole is listed in the dataset of EPA Human Health Benchmarks for Pesticides under the Safe Drinking Water Act (40 eCFR 141)

Status: Active Update: 26-04-2022 https://echa.europa.eu/registration-dossier/-/registered-dossier/13353

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.

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%).

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.

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.

For more Absorption, Distribution and Excretion (Complete) data for 1H-1,2,4-Triazole (6 total), please visit the HSDB record page.

Used in organic synthesis; [IUCLID]

Intermediate

2023: 5,500,000 - <7,000,000 lb；2022: 7,000,000 - <8,500,000 lb；2021: 4,000,000 - <5,500,000 lb；2020: 4,000,000 - <5,500,000 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).

Production volumes for non-confidential chemicals reported under the Inventory Update Rule. [Table#7598]

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.

Pesticide, Fertilizer, and Other Agricultural Chemical Manufacturing

1H-1,2,4-Triazole: ACTIVE