Substance profile
Amitrole
Amitrole is a transparent to off white crystalline powder and is odorless.
01 · Identification
What Amitrole is
Amitrole is a transparent to off white crystalline powder and is odorless. Its molecular formula is C2H4N4 and its molecular weight is 84.08 g/mol. It melts at 159 °C.
Under the GHS it carries the signal word Warning. It is classed as carcinogens.
02 · Identifiers
Amitrole identifiers and molecular data
Amitrole CAS number and EC number
Amitrole molecular formula and molecular weight
Other names for Amitrole
- amitrole (ISO)
- 1,2,4-triazol-3-ylamine
03 · GHS classification
Amitrole hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Amitrole pictograms and signal word
Amitrole hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Specific target organ toxicity - repeated exposure GHS chapter 3.9 | Category 2 | H373 | GHS08 |
| Hazardous to the aquatic environment - chronic GHS chapter 4.1 | Category 2 | H411 | GHS09 |
Amitrole hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H361d | Suspected of damaging the unborn child. |
| H373 | May cause damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H411 | Toxic to aquatic life with long lasting effects. |
This page lists only the codes assigned to Amitrole. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.
Safety Data Sheet
Getting an SDS for Amitrole
A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of Amitrole issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.
04 · Precautionary statements
Amitrole precautionary statements
CLP Annex VI assigns 6 precautionary statements to Amitrole. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.
Prevention
What to do before and during handling so the hazard never happens.
Response
What to do once exposure, spillage or fire has already happened.
Disposal
What has to happen to the contents and the empty container.
Reading the notation. … is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.
05 · Names in the regulation
Amitrole name in 23 EU languages
CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.
| Language | Name in CLP Annex VI Part 3 |
|---|---|
| Bulgarian български | амитрол (ISO) 1,2,4-триазол-3-иламин |
| Spanish español | Amitrol (ISO) 1,2,4-triazol-3-ilamina |
| Czech čeština | amitrol (ISO) 1 H -1,2,4-triazol-3-amin |
| Danish dansk | amitrol (ISO) 1,2,4-triazol-3-ylamin |
| German Deutsch | Amitrol (ISO) 1,2,4-triazol-3-ylamin |
| Estonian eesti | amitrool (ISO) 1,2,4-triasool-3-üülamiin |
| Greek ελληνικά | amitrole (αμιτρόλη) (ISO) 1,2,4-τριαζολ-3-υλαμίνη |
| English English | amitrole (ISO) 1,2,4-triazol-3-ylamine |
| French français | amitrole (ISO) 1,2,4-triazol-3-ylamine |
| Croatian hrvatski | amitrol (ISO) 1,2,4-triazol-3-ilamin |
| Italian italiano | amitrol (ISO) 1,2,4-triazol-3-ilammina |
| Latvian latviešu | amitrols (ISO) 1,2,4-triazol-3-ilamīns |
| Lithuanian lietuvių | amitrolis (ISO) 1,2,4-triazol-3-ilaminas |
| Hungarian magyar | amitrol (ISO) 1,2,4-triazol-3-ilamin |
| Maltese Malti | amitrol (ISO) 1,2,4-triażol-3-ilammin |
| Dutch Nederlands | amitrool (ISO) 1,2,4-triazool-3-ylamine |
| Polish polski | amitrol (ISO) 1,2,4-triazol-3-iloamina |
| Portuguese português | amitrole (ISO) 1,2,4-triazol-3-ilamina |
| Romanian română | amitrol (ISO) 1,2,4-triazol-3-ilamină |
| Slovak slovenčina | amitrol (ISO) 1,2,4-triazol-3-amín |
| Slovenian slovenščina | amitrol (ISO) 1,2,4-triazol-3-ilamin |
| Finnish suomi | amitroli (ISO 1,2,4-triatsoli-3-yyliamiini |
| Swedish svenska | amitrol (ISO) 1,2,4-triazol-3-ylamin |
All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.
06 · Label elements
Amitrole GHS label elements
Everything CLP Annex VI fixes for Amitrole, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Warning
Amitrole
- Suspected of damaging the unborn child.
- May cause damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
- Toxic to aquatic life with long lasting effects.
- Do not breathe dust/fume/gas/mist/vapours/spray.
- Do not eat, drink or smoke when using this product.
- Avoid release to the environment.
- Get medical advice/attention if you feel unwell.
- Collect spillage.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Amitrole in the GHS label constructor →
07 · Health hazards
Amitrole health hazards and exposure limits
Amitrole hazard summary
The major hazards encountered in the use and handling of 2-amino-1,3,4-triazole stem from its toxicologic properties. Exposure to this odorless, colorless-to-white, crystalline substance may occur from its manufacture, handling, and use as a weed-killer. Effects from exposure may include dermal irritation, muscle spasms, shortness-of-breath, and anorexia. Also, the International Agency for Research on Cancer (IARC) has designated this substance as a Group 3 carcinogen, meaning, "The agent is not classifiable as to its carcinogenicity to humans." OSHA has set a Time Weighted Average (TWA) limit of 0.2 mg/cu m as a final rule to become effective December 31, 1992. In activities and situations where over-exposure may occur, wear a protective suit and a carefully fitted respirator. If contact should occur, irrigate exposed eyes with copious amounts of tepid water for at least 15 minutes, and wash exposed skin thoroughly with soap and water. Smoking, drinking, and eating should be prohibited in 2-amino-1,3,4-tiazole work areas, and cleanliness following the handling of this substance should be emphasized. While considered nonflammable, 2-amino-1,3,4-triazole will emit highly toxic fumes when strongly heated. 2-Amino-1,3,4-triazole should be kept in securely sealed containers, away from light (which will act to decompose the substance). Choice of container should take into consideration that 2-amino-1,3,4-triazole is mildly corrosive to iron, aluminum, copper, and copper alloys.
Source: Hazardous Substances Data Bank (HSDB)
Amitrole carcinogenicity classification
Cancer Classification: Group B2 Probable Human Carcinogen
Source: Hazardous Substances Data Bank (HSDB)
The Human Health Assessment Group in EPA's Office of Health and Environmental Assessment has evaluated amitrole for carcinogenicity. According to their analysis, the weight-of-evidence for amitrole is group B2, which is based on inadequate evidence in humans and sufficient evidence in animals. As a group B2 chemical, amitrole is considered a probable human carcinogen.
Source: Hazardous Substances Data Bank (HSDB)
An IARC group and a CLP classification answer different questions. IARC judges whether the evidence for cancer in humans is strong enough; CLP Annex VI is the legally binding EU classification. A substance can carry one and not the other.
Amitrole occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | none See Appendix G | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 0.2 mg/m³ | Occupational Safety and Health Administration (OSHA) |
| REL | Ca TWA 0.2 mg/m3 See Appendix A | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | A potential occupational carcinogen. (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | NIOSH considers amitrole to be a potential occupational carcinogen. | Hazardous Substances Data Bank (HSDB) |
| IDLH | Ca [N.D.] | The National Institute for Occupational Safety and Health (NIOSH) |
These are United States values. The European Union sets its own indicative and binding limits, and the figure that applies at a given workplace is the one in the local regulation — not the one shown here.
08 · Physical and chemical properties
Amitrole properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
Amitrole melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 159 °C (318.2 °F) | HSDB | |
| 158.89 °C (318 °F) | NIOSH |
Amitrole density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.14 g/cm³ | NIOSH | |
| 1.138 g/cm³ | at 20 °C | HSDB |
Amitrole solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | In water, 2.8X10+5 mg/L at 25 °C | at 25 °C | HSDB |
| (77 °F): 28% | at 25 °C | NIOSH | |
| Solubility in water, g/l at 25 °C: 280 | at 25 °C | ICSC |
Amitrole vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 4.41e-7 mmHg | at 20 °C | CAMEO |
| 0.000001 mmHg | at 20 °C | DOE PAC | |
| 4.4e-7 mmHg | at 25 °C | HSDB |
Amitrole lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | Noncombustible Solid, but may be dissolved in flammable liquids. | NIOSH |
Amitrole vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 2.9 (air = 1) | ICSC |
Amitrole corrosivity
| Property | Value | Conditions | Source |
|---|---|---|---|
| Corrosivity | MILDLY CORROSIVE TO IRON, ALUMINUM, COPPER, & COPPER ALLOYS. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Amitrole fire and explosion behaviour
These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.
Amitrole fire potential
Aqueous, nonflammable, as amitrol-t; dry powder, non-flammable, as amizol.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Amitrole storage and handling
Amitrole safe storage
Store in an area without drain or sewer access. Separated from strong acids, strong oxidants, acid anhydrides and acid chlorides. Do NOT store or transport in containers made from iron, aluminium or copper and its alloys. Separated from food and feedstuffs.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Amitrole storage conditions
Store at room temperature
Source: Hazardous Substances Data Bank (HSDB)
Amitrole incompatible materials
Light (decomposes), strong oxidizers [Note: Corrosive to iron, aluminum & copper].
Source: Hazardous Substances Data Bank (HSDB)
Amitrole reactivity
AMITROLE is a triazole derivative. The triazoles are a group that contain several derivatives that are highly explosive materials. They are sensitive to heat, friction, and impact. Sensitivity varies with the type substitution to the triazole ring. Metal chelated and halogen substitution of the triazole ring make for a particularly heat sensitive material. Azido and nitro derivatives have been employed as high explosives. No matter the derivative these materials should be treated as explosives. AMITROLE forms chelates with some metals. It is corrosive to iron, copper and aluminum. Forms salts with most acids and alkalis. This compound is incompatible with strong oxidizers, strong acids, acid chlorides and acid anhydrides (NTP, 1992).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Amitrole in the storage compatibility matrix →
11 · Questions
Amitrole — frequently asked questions
What is the CAS number of Amitrole?
The CAS number of Amitrole is 61-82-5. Its EC number is 200-521-5.
What is the chemical formula of Amitrole?
The molecular formula of Amitrole is C2H4N4 and its molecular weight is 84.08 g/mol.
What does a Amitrole label have to show?
Under CLP Annex VI the label for Amitrole carries the pictograms Health hazard and Environment and the signal word is Warning.
Is Amitrole flammable?
CLP Annex VI assigns Amitrole no flammability hazard class. That is not a statement that it cannot burn: the harmonised list only records the hazards that were assessed for it.
Is Amitrole a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Amitrole. Annex VI is a list of agreed classifications, not a list of substances found safe, so this is an absence of a classification rather than a clean bill of health. IARC places it in Group 3: not classifiable as to its carcinogenicity to humans.
What is the exposure limit for Amitrole?
The US occupational exposure limit reported for Amitrole is none See Appendix G (The National Institute for Occupational Safety and Health (NIOSH)). Limits differ by country: the EU sets its own indicative and binding values, and the figure that applies at a given workplace is the one in the local regulation.
What is the melting point of Amitrole?
The melting point reported for Amitrole is 159 °C (318.2 °F) (HSDB).
How should Amitrole be stored?
Store at room temperature (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Amitrole
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