Substance profile
Acetonitrile
Acetonitrile is colorless, limpid liquid with an aromatic odor.
01 · Identification
What Acetonitrile is
Acetonitrile is colorless, limpid liquid with an aromatic odor. Its molecular formula is C2H3N and its molecular weight is 41.05 g/mol. It boils at 81.6 °C, melts at -44 °C.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
02 · Identifiers
Acetonitrile identifiers and molecular data
Acetonitrile CAS number and EC number
Acetonitrile molecular formula and molecular weight
Other names for Acetonitrile
- ACN
- methyl cyanide
- CH3CN
- Acetonitrile Cluster
- Cyanomethane
- Ethanenitrile
- Ethyl Nitrile
- Methane, Cyano-
- Methanecarbonitrile
- Methyl Cyanide (Mecn)
- Usaf Ek-488
- cyanomethane
03 · GHS classification
Acetonitrile hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Acetonitrile pictograms and signal word
Acetonitrile 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 4 | H302 | GHS07 |
| Acute toxicity - dermal GHS chapter 3.1 | Category 4 | H312 | GHS07 |
| Acute toxicity - inhalation GHS chapter 3.1 | Category 4 | H332 | GHS07 |
| Serious eye damage/eye irritation GHS chapter 3.3 | Category 2A | H319 | GHS07 |
Acetonitrile hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H225 | Highly flammable liquid and vapour. |
| H332 | Harmful if inhaled. |
| H312 | Harmful in contact with skin. |
| H302 | Harmful if swallowed. |
| H319 | Causes serious eye irritation. |
This page lists only the codes assigned to Acetonitrile. 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 Acetonitrile
Our own Acetonitrile safety data sheet walks through all sixteen sections of the published data. What it is not is the document an inspector asks for: an SDS is issued for a product by its supplier, so the sheet covering the grade actually standing in your store exists only in that supplier’s version. Collecting those and keeping them current as suppliers revise them is a separate job.
04 · Precautionary statements
Acetonitrile precautionary statements
CLP Annex VI assigns 20 precautionary statements to Acetonitrile. 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
Acetonitrile 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 | ацетонитрил цианометан |
| Spanish español | Acetonitrilo cianometano |
| Czech čeština | acetonitril methylkyanid |
| Danish dansk | acetonitril cyanmethan |
| German Deutsch | Acetonitril Cyanomethan |
| Estonian eesti | atsetonitriil tsüanometaan |
| Greek ελληνικά | ακετονιτρίλιο |
| English English | acetonitrile cyanomethane |
| French français | acétonitrile cyanométhane |
| Croatian hrvatski | acetonitril cijanometan |
| Italian italiano | acetonitrile |
| Latvian latviešu | acetonitrils ciānmetāns |
| Lithuanian lietuvių | acetonitrilas cianometanas |
| Hungarian magyar | acetonitril cianometán |
| Maltese Malti | aċetonitril ċjanometan |
| Dutch Nederlands | acetonitril cyaanmethaan |
| Polish polski | acetonitryl cyjanek metylunitryl kwasu octowego |
| Portuguese português | acetonitrilo cianometano |
| Romanian română | acetonitril cianometan |
| Slovak slovenčina | acetonitril kyanometán |
| Slovenian slovenščina | acetonitril cianometan |
| Finnish suomi | asetonitriili syanometaani |
| Swedish svenska | acetonitril cyanometan |
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
Acetonitrile GHS label elements
Everything CLP Annex VI fixes for Acetonitrile, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Acetonitrile
- Highly flammable liquid and vapour.
- Harmful if inhaled.
- Harmful in contact with skin.
- Harmful if swallowed.
- Causes serious eye irritation.
- 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.
- Wash … thoroughly after handling.
- Do not eat, drink or smoke when using this product.
- Use only outdoors or in a well-ventilated area.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- IF ON SKIN:
- IF INHALED:
- IF IN EYES:
- Call a POISON CENTER/doctor/… if you feel unwell.
- Get medical advice/attention.
- Rinse mouth.
- If eye irritation persists:
- Remove contact lenses, if present and easy to do. Continue rinsing.
- 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 Acetonitrile in the GHS label constructor →
07 · Health hazards
Acetonitrile health hazards and exposure limits
Acetonitrile hazard summary
Acetonitrile has many uses, including as a solvent, for spinning fibers, and in lithium batteries. It is primarily found in air from automobile exhaust and manufacturing facilities. Acute (short-term) inhalation exposure results in irritation of mucous membranes. Chronic (long-term) exposure results in central nervous system effects, such as headaches, numbness, and tremors. No data are available on its carcinogenic effects in humans; EPA has classified it as a Group D, not classifiable as to human carcinogenicity.
Source: EPA Hazardous Air Pollutants
Acetonitrile carcinogenicity classification
Under the conditions of these 2-year inhalation studies, there was equivocal evidence of carcinogenic activity of acetonitrile in male F344/N rats based on marginally increased incidences of hepatocellular adenoma and carcinoma. There was no evidence of carcinogenic activity of acetonitrile in female F344/N rats exposed to 100, 200, or 400 ppm. There was no evidence of carcinogenic activity of acetonitrile in male or female B6C3F1 mice exposed to 50, 100, or 200 ppm.
Source: US National Toxicology Program · TR-447: Toxicology and Carcinogenesis Studies of Acetonitrile (CASRN 75-05-8) in F344/N Rats and B6C3F1 Mice (Inhalation Studies) (1996 )
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.
Acetonitrile occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 40.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| PEL | 40 ppm (70 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| PEL | TWA 40 ppm (70 mg/m³) See Appendix G | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 20 ppm (34 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| REL | TWA 20 ppm (34 mg/m³) | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 137 ppm (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 137.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| IDLH | 500 ppm | Hazardous Substances Data Bank (HSDB) |
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
Acetonitrile 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.
Acetonitrile boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 81.6 °C (178.9 °F) | at 760 mmHg | HSDB |
| 20 °C (68 °F) | HSDB | ||
| 81.67 °C (179 °F) | NIOSH |
Acetonitrile melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -44 °C (-47.2 °F) | HSDB | |
| -45 °C (-49 °F) | NIOSH |
Acetonitrile density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.78 g/cm³ | NIOSH | |
| 0.8 g/cm³ | ICSC | ||
| 0.787 g/cm³ | at 20 °C | CAMEO |
Acetonitrile solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | In water, >800 g/L at 25 °C | at 25 °C | HSDB |
| In water, infinite solubility at 25 °C | at 25 °C | HSDB |
Acetonitrile vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 73 mmHg | NIOSH | |
| 73 mmHg | at 20 °C | CAMEO | |
| 88.8 mmHg | at 25 °C | HSDB |
Acetonitrile flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 5.56 °C (42 °F) | HSDB |
Acetonitrile autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 523.89 °C (975 °F) | HSDB | |
| 524 °C (975.2 °F) | ICSC |
Acetonitrile lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 3 % by volume | HSDB |
Acetonitrile upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 16 % by volume | HSDB |
Acetonitrile vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 1.42 (air = 1) | HSDB | |
| 1.4 (air = 1) | ICSC |
Acetonitrile odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | Low: 70.0 mg/cu m; High: 70.0 mg/cu m; Irritating: 875 mg/cu m | HSDB | |
| Odor Threshold Low: 40.0 [ppm] | Haz-Map | ||
| Odor Threshold High: 1161.0 [ppm] | Haz-Map |
Acetonitrile critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 272.3 °C (522.1 °F) | HSDB |
Acetonitrile corrosivity
| Property | Value | Conditions | Source |
|---|---|---|---|
| Corrosivity | Liquid acetonitrile will attack some forms of plastics, rubber, and coatings. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Acetonitrile 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.
Acetonitrile fire potential
Dangerous fire hazard when exposed to heat, flame or oxidizers.
Source: Hazardous Substances Data Bank (HSDB)
Solubility
Miscible with methanol, methyl acetate, ethyl acetate, ether, acetamide solutions, chloroform, carbon tetrachloride, ethylene chloride, and with many unsaturated hydrocarbons; immiscible with many saturated hydrocarbons (petroleum fractions).
Source: HSDB
10 · Handling and storage
Acetonitrile storage and handling
Acetonitrile reactive group
CAMEO Chemicals places Acetonitrile in the reactive group Nitriles. Compatibility with other chemicals is worked out from the group, not from the individual substance — which is why two substances you have never seen react can still be flagged as a pair that must be separated.
A reactive group is a CAMEO Chemicals (US NOAA) grouping, not a GHS hazard class: it has no code, no category and no legal force. It is what the storage compatibility matrix on this site computes from.
Acetonitrile safe storage
Fireproof. Keep in a well-ventilated room. Separated from acids, bases, strong oxidants and food and feedstuffs. Well closed.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Acetonitrile storage conditions
Protect containers against physical damage. Outdoor or detached storage is preferable. Separate from any sources of ignition and combustible materials. Storage room should be well-ventilated.
Source: Hazardous Substances Data Bank (HSDB)
Acetonitrile incompatible materials
Strong oxidizers such as chlorine, bromine, and fluorine; chlorosulfonic acid; oleum or sulfuric acid. May accumulate static electricial charges, and may cause ignition of its vapors.
Source: Hazardous Substances Data Bank (HSDB)
Acetonitrile reactivity
ACETONITRILE decomposes when heated to produce deadly toxic hydrogen cyanide gas and oxides of nitrogen. Strongly reactive [Hawley]. May react vigorously with strong oxidizing reagents, sulfuric acid, chlorosulfonic acid, sulfur trioxide, perchlorates, nitrating reagents, and nitric acid. [Sax, 9th ed., 1996, p. 20]. Potentially explosive in contact with nitrogen-fluorine compounds (e.g., tetrafluorourea) [Fraser, G. W. et al., Chem. Comm., 1966, p. 532].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Acetonitrile in the storage compatibility matrix →
11 · Transport
Acetonitrile 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.
Acetonitrile under UN 1648 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| ACETONITRILE | 3 | F1 | II | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 3 is “Flammable liquids” (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) |
|---|---|---|---|
| Acetonitrile | 3 | II | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 3 is “Flammable and combustible liquid” (49 CFR 173.2).
12 · Questions
Acetonitrile — frequently asked questions
What is the CAS number of Acetonitrile?
The CAS number of Acetonitrile is 75-05-8. Its EC number is 200-835-2.
What is the chemical formula of Acetonitrile?
The molecular formula of Acetonitrile is C2H3N and its molecular weight is 41.05 g/mol.
What does a Acetonitrile label have to show?
Under CLP Annex VI the label for Acetonitrile carries the pictograms Flame and Exclamation mark and the signal word is Danger.
Is Acetonitrile flammable?
Yes. CLP Annex VI assigns Acetonitrile H225 — highly flammable liquid and vapour. The flash point reported for it is 5.56 °C (42 °F) (HSDB).
Is Acetonitrile a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Acetonitrile. 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 Acetonitrile?
The US occupational exposure limit reported for Acetonitrile is 40.0 [ppm] (Haz-Map, Information on Hazardous Chemicals and Occupational Diseases). 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 Acetonitrile?
The boiling point reported for Acetonitrile is 81.6 °C (178.9 °F), at 760 mmHg (HSDB).
What is the melting point of Acetonitrile?
The melting point reported for Acetonitrile is -44 °C (-47.2 °F) (HSDB).
How should Acetonitrile be stored?
CLP Annex VI assigns Acetonitrile the storage statement P403. Protect containers against physical damage. Outdoor or detached storage is preferable. Separate from any sources of ignition and combustible materials. Storage room should be well-ventilated. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Acetonitrile
Keep going: substances starting with A, or search the whole database by name, CAS number, pictogram or signal word.
Next