Substance profile
Methacrylonitrile
Methacrylonitrile is a colorless liquid with odor-like bitter almonds.
01 · Identification
What Methacrylonitrile is
Methacrylonitrile is a colorless liquid with odor-like bitter almonds. Its molecular formula is C4H5N and its molecular weight is 67.09 g/mol. It boils at 90.3 °C, melts at -35.8 °C, is miscible with water.
Under the GHS it carries the signal word Danger. It is classed as flammable agents - 3rd degree.
02 · Identifiers
Methacrylonitrile identifiers and molecular data
Methacrylonitrile CAS number and EC number
Methacrylonitrile molecular formula and molecular weight
Other names for Methacrylonitrile
- 2-methyl-2-propene nitrile
03 · GHS classification
Methacrylonitrile hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Methacrylonitrile pictograms and signal word
Methacrylonitrile hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Flammable liquids GHS chapter 2.6 | Category 2 | H225 | GHS02 |
| Acute toxicity - oral GHS chapter 3.1 | Category 3 | H301 | GHS06 |
| Acute toxicity - dermal GHS chapter 3.1 | Category 3 | H311 | GHS06 |
| Acute toxicity - inhalation GHS chapter 3.1 | Category 3 | H331 | GHS06 |
| Skin sensitisation GHS chapter 3.4 | Category 1 or 1A or 1B | H317 | GHS07 |
Where two values are shown with “or”, the hazard statement is shared by more than one category or by more than one class, and the code alone does not say which. H272, for example, belongs to oxidising liquids and to oxidising solids — the physical state decides. The binding answer for a specific entry is in the CLP Annex VI table itself.
Methacrylonitrile hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H225 | Highly flammable liquid and vapour. |
| H331 | Toxic if inhaled. |
| H311 | Toxic in contact with skin. |
| H301 | Toxic if swallowed. |
| H317 | May cause an allergic skin reaction. |
This page lists only the codes assigned to Methacrylonitrile. 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 Methacrylonitrile
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 Methacrylonitrile 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
Methacrylonitrile precautionary statements
CLP Annex VI assigns 19 precautionary statements to Methacrylonitrile. 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.
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
Methacrylonitrile 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 | метакрилонитрил 2-метил-2-пропеннитрил |
| Spanish español | Metacrilonitrilo 2-metil-2-propenonitrilo |
| Czech čeština | methakrylonitril 2-methylprop-2-ennitril |
| Danish dansk | methacrylnitril 2-methyl-2-propennitril |
| German Deutsch | Methacrylnitril 2-Methyl-2-propennitril |
| Estonian eesti | metakrülonitriil 2-metüül-2-propeennitriil |
| Greek ελληνικά | μεθακρυλονιτρίλιο 2-μεθυλο-2-προπενονιτρίλιο |
| English English | methacrylonitrile 2-methyl-2-propene nitrile |
| French français | méthacrylonitrile 2-méthyl-2-propène-nitrile |
| Croatian hrvatski | metakrilonitril 2-metil-2-propen-nitril |
| Italian italiano | metacrilonitrile 2-metil-2-propene-nitrile |
| Latvian latviešu | metakrilnitrils 2-metil-2-propēna nitrils |
| Lithuanian lietuvių | metakrilnitrilas 2-metil-2-propennitrilas |
| Hungarian magyar | metakrilnitril 2-metil-2-propénnitril |
| Maltese Malti | metakrilonitril nitril ta’ 2-metil-2-propen |
| Dutch Nederlands | methacrylonitril 2-methyl-2-propeennitril |
| Polish polski | metakrylonitryl 2-metylprop-2-enonitrylnitryl kwasu metakrylowegocyjanek 1-metylowinylu |
| Portuguese português | metacrilonitrilo 2-metil-2-propenonitrilo |
| Romanian română | metacrilonitril 2-metil-2-propenonitril |
| Slovak slovenčina | metakrylonitril 2-metylprop-2-énnitril |
| Slovenian slovenščina | metakrilonitril 2-metil-2-propen nitril |
| Finnish suomi | metakryylinitriili 2-metyyli-2-propeeninitriili |
| Swedish svenska | metakrylonitril 2-metyl-2-propennitril |
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
Methacrylonitrile GHS label elements
Everything CLP Annex VI fixes for Methacrylonitrile, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Methacrylonitrile
- Highly flammable liquid and vapour.
- Toxic if inhaled.
- Toxic in contact with skin.
- Toxic if swallowed.
- May cause an allergic skin reaction.
- Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
- Keep container tightly closed.
- Use explosion-proof [electrical/ventilating/lighting/…] equipment.
- Use only non-sparking tools.
- Do not breathe dust/fume/gas/mist/vapours/spray.
- Avoid breathing dust/fume/gas/mist/vapours/spray.
- Do not eat, drink or smoke when using this product.
- Use only outdoors or in a well-ventilated area.
- Contaminated work clothing should not be allowed out of the workplace.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- IF ON SKIN:
- IF INHALED:
- Immediately call a POISON CENTER/doctor/…
- Get medical advice/attention.
- Rinse mouth.
- If skin irritation or rash occurs:
- Wash with plenty of water/…
- Store in a well-ventilated place.
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Methacrylonitrile in the GHS label constructor →
07 · Health hazards
Methacrylonitrile health hazards and exposure limits
Methacrylonitrile hazard summary
Inhalation toxicity is comparable to that of acrylonitrile; Causes paralysis of hind limbs and seizures in dogs exposed to 13.5 ppm for 90 days; [ACGIH] An eye and respiratory tract irritant; Can cause cyanide poisoning; [ICSC] A skin sensitizer; [Quick CPC] A lachrymator; [HSDB] Methacrylonitrile, stabilized (UN3079) has warning of explosive polymerization; [ERG 2016] See NITRILES.
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Methacrylonitrile carcinogenicity classification
Under the conditions of these 2-year gavage studies,there was no evidence of carcinogenic activity of methacrylonitrile in male or female F344/N rats administered 3,10,or 30 mg/kg. There was no evidence of carcinogenic activity of methacrylonitrile in male or female B6C3F1 mice administered 1.5,3,or 6 mg/kg.
Source: US National Toxicology Program · TR-497: Toxicology and Carcinogenesis Studies of Methacrylonitrile (CASRN 126-98-7) in F344/N Rats and B6C3F1 Mice (Gavage Studies) (2001 )
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.
Methacrylonitrile occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | none See Appendix G | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 1 ppm (3 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| REL | TWA 1 ppm (3 mg/m³) [skin] | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 4 ppm (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 4.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| IDLH | Excerpts from Documentation for IDLHs: Acute inhalation toxicity is similar to acrylonitrile; [ACGIH] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
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
Methacrylonitrile 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.
Methacrylonitrile boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 90.3 °C (194.5 °F) | at 760 mmHg | HSDB |
| 90.56 °C (195 °F) | NIOSH | ||
| 90 °C (194 °F) | at 760 mmHg | CAMEO |
Methacrylonitrile melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -35.8 °C (-32.4 °F) | HSDB | |
| -35.56 °C (-32 °F) | NIOSH | ||
| -35.78 °C (-32.4 °F) | CAMEO |
Methacrylonitrile density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.8 g/cm³ | NIOSH | |
| 0.8001 g/cm³ | at 20 °C | HSDB |
Methacrylonitrile solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Miscible with acetone, octane, toluene @ 20-25 °C | HSDB | |
| Sol in alcohol, ether | HSDB | ||
| In water, 2.54X10+4 mg/l @ 25 °C | at 25 °C | HSDB |
Methacrylonitrile vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 71.2 mmHg | at 25 °C | HSDB |
| 71 mmHg | at 25 °C | NIOSH | |
| 64.9553 mmHg | at 25 °C | ICSC |
Methacrylonitrile flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 13 °C (55.4 °F) | HSDB | |
| 1.11 °C (34 °F) | NIOSH | ||
| 12.78 °C (55 °F) | CAMEO |
Methacrylonitrile lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 2 % by volume | HSDB |
Methacrylonitrile upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 6.8 % by volume | HSDB |
Methacrylonitrile vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 2.31 (air = 1) | HSDB | |
| 2.3 (air = 1) | ICSC |
Methacrylonitrile odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | ... IT SHOULD BE NOTED THAT METHACRYLONITRILE CANNOT BE DETECTED BY ITS SMELL EVEN AT CONCENTRATIONS WHICH ARE ALREADY DANGEROUS FOR HUMANS. | HSDB | |
| An odor threshold of 2.1 ppm has been reported. | HSDB | ||
| Odor Threshold Low: 6.9 [ppm] | Haz-Map |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Methacrylonitrile 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.
Methacrylonitrile fire potential
METHACRYLONITRILE EVOLVES FLAMMABLE CONCENTRATIONS OF VAPOR AT TEMPERATURES DOWN TO 12.8 °C. THUS, AT ROOM TEMPERATURES, FLAMMABLE ... CONCENTRATIONS ARE LIABLE TO BE PRESENT IN ABSENCE OF PRECAUTIONS. THE NORMAL DANGERS ASSOCIATED WITH FIRE ... ARE INTENSIFIED BY THE LETHAL NATURE OF THE FUMES & VAPORS EVOLVED.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Methacrylonitrile storage and handling
Methacrylonitrile safe storage
Store only if stabilized. Fireproof. Cool. Keep in the dark. Separated from food and feedstuffs.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Methacrylonitrile incompatible materials
Strong acids, strong oxidizers, alkali, light. [Note: Polymerization may occur due to elevated temperature, visible light, or contact with a concentrated alkali.]
Source: Hazardous Substances Data Bank (HSDB)
Methacrylonitrile reactivity
METHACRYLONITRILE is a colorless, flammable, toxic liquid. Explosive in the form of vapor when exposed to heat, flame or sparks. When heated to decomposition it emits toxic fumes of nitrile and oxides of nitrogen [Lewis, 3rd ed., 1993, p. 829].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Methacrylonitrile in the storage compatibility matrix →
11 · Transport
Methacrylonitrile UN number and transport classification
Transport classification is a separate system from the GHS classification above. It decides how a package is marked and how a load may be carried; it does not follow from the workplace label, and the workplace label does not follow from it. The entries below are linked by CAS number, never by name.
Methacrylonitrile under UN 3079 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| METHACRYLONITRILE, STABILIZED | 6.1 | TF1 | I | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 6.1 is “Toxic substances” (ADR 2.1.1.1).
United States · 49 CFR 172.101 Hazardous Materials Table
| Proper shipping name (column 2) | Class or division | PG | Labels (column 6) |
|---|---|---|---|
| Methacrylonitrile, stabilized | 6.1 | I | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 6.1 is “Poisonous materials” (49 CFR 173.2).
12 · Questions
Methacrylonitrile — frequently asked questions
What is the CAS number of Methacrylonitrile?
The CAS number of Methacrylonitrile is 126-98-7. Its EC number is 204-817-5.
What is the chemical formula of Methacrylonitrile?
The molecular formula of Methacrylonitrile is C4H5N and its molecular weight is 67.09 g/mol.
What does a Methacrylonitrile label have to show?
Under CLP Annex VI the label for Methacrylonitrile carries the pictograms Flame and Skull and crossbones and the signal word is Danger.
Is Methacrylonitrile flammable?
Yes. CLP Annex VI assigns Methacrylonitrile H225 — highly flammable liquid and vapour. The flash point reported for it is 13 °C (55.4 °F) (HSDB).
Is Methacrylonitrile a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Methacrylonitrile. 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.
What is the exposure limit for Methacrylonitrile?
The US occupational exposure limit reported for Methacrylonitrile 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 boiling point of Methacrylonitrile?
The boiling point reported for Methacrylonitrile is 90.3 °C (194.5 °F), at 760 mmHg (HSDB).
What is the melting point of Methacrylonitrile?
The melting point reported for Methacrylonitrile is -35.8 °C (-32.4 °F) (HSDB).
How should Methacrylonitrile be stored?
CLP Annex VI assigns Methacrylonitrile the storage statement P403.
Nearby
Substances next to Methacrylonitrile
Keep going: substances starting with M, or search the whole database by name, CAS number, pictogram or signal word.