Substance profile
Acetic Anhydride
Acetic Anhydride is a colorless liquid with a strong acetic odor.
01 · Identification
What Acetic Anhydride is
Acetic Anhydride is a colorless liquid with a strong acetic odor. Its molecular formula is C4H6O3 and its molecular weight is 102.09 g/mol. It boils at 140 °C, melts at -73.4 °C.
Under the GHS it carries the signal word Danger. It is classed as corrosives.
02 · Identifiers
Acetic Anhydride identifiers and molecular data
Acetic Anhydride CAS number and EC number
Acetic Anhydride molecular formula and molecular weight
03 · GHS classification
Acetic Anhydride hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Acetic Anhydride pictograms and signal word
Acetic Anhydride hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Flammable liquids GHS chapter 2.6 | Category 3 | H226 | GHS02 |
| Acute toxicity - oral GHS chapter 3.1 | Category 4 | H302 | GHS07 |
| Acute toxicity - inhalation GHS chapter 3.1 | Category 4 | H332 | GHS07 |
| Skin corrosion/irritation GHS chapter 3.2 | Category 1A or 1B or 1C | H314 | GHS05 |
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.
Acetic Anhydride hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H226 | Flammable liquid and vapour. |
| H332 | Harmful if inhaled. |
| H302 | Harmful if swallowed. |
| H314 | Causes severe skin burns and eye damage. |
This page lists only the codes assigned to Acetic Anhydride. 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 Acetic Anhydride
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 Acetic Anhydride 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
Acetic Anhydride precautionary statements
CLP Annex VI assigns 15 precautionary statements to Acetic Anhydride. 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
Acetic Anhydride 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 | оцетен анхидрид |
| Spanish español | Anhídrido acético |
| Czech čeština | acetanhydrid |
| Danish dansk | eddikesyreanhydrid |
| German Deutsch | Essigsäureanhydrid |
| Estonian eesti | atseetanhüdriid |
| Greek ελληνικά | οξικός ανυδρίτης |
| English English | acetic anhydride |
| French français | anhydride acétique |
| Croatian hrvatski | octeni anhidrid |
| Italian italiano | anidride acetica |
| Latvian latviešu | etiķskābes anhidrīds |
| Lithuanian lietuvių | acetanhidridas |
| Hungarian magyar | ecetsav-anhidrid |
| Maltese Malti | anidride aċetiku |
| Dutch Nederlands | azijnzuuranhydride |
| Polish polski | bezwodnik octowy |
| Portuguese português | anidrido acético |
| Romanian română | anhidridă acetică |
| Slovak slovenčina | acetanhydrid |
| Slovenian slovenščina | anhidrid ocetne kisline |
| Finnish suomi | etikkahappoanhydridi |
| Swedish svenska | ättiksyraanhydrid |
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
Acetic Anhydride GHS label elements
Everything CLP Annex VI fixes for Acetic Anhydride, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Acetic Anhydride
- Flammable liquid and vapour.
- Harmful if inhaled.
- Harmful if swallowed.
- Causes severe skin burns and eye damage.
- 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.
- 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 INHALED:
- Immediately call a POISON CENTER/doctor/…
- Call a POISON CENTER/doctor/… if you feel unwell.
- Rinse mouth.
- Do NOT induce vomiting.
- Store in a well-ventilated place.
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Acetic Anhydride in the GHS label constructor →
07 · Health hazards
Acetic Anhydride health hazards and exposure limits
Acetic Anhydride hazard summary
Evidence of skin sensitization in a guinea pig study, but insufficient data to recommend SEN notation; Workers exposed to >5 ppm have immediate eye and respiratory irritation; [ACGIH] Liquid causes second degree burns after contact for a few minutes. [CHRIS] Corrosive to skin; [Quick CPC] Inhalation of high concentrations can cause bronchospasm and pulmonary edema. [NIOSH Guidelines for Chemical Hazards] A lachrymator; [CHEMINFO]
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Acetic Anhydride occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 5.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| PEL | 5 ppm (20 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| PEL | TWA 5 ppm (20 mg/m3) See Appendix G | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 5 ppm (20 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| REL | C 5 ppm (20 mg/m3) | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 200 ppm (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 200.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| IDLH | 200 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
Acetic Anhydride 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.
Acetic Anhydride boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 139.5 °C (283.1 °F) | HSDB | |
| 138.89 °C (282 °F) | NIOSH | ||
| 139.55 °C (283.2 °F) | at 760 mmHg | CAMEO |
Acetic Anhydride melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -73.4 °C (-100.1 °F) | HSDB | |
| -72.78 °C (-99 °F) | NIOSH | ||
| -73.11 °C (-99.6 °F) | CAMEO |
Acetic Anhydride density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.08 g/cm³ | NIOSH | |
| 1.082 g/cm³ | at 20 °C | HSDB |
Acetic Anhydride solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Slowly soluble in water, forming acetic acid | HSDB | |
| In water, 120 g/L at 20 °C | at 20 °C | HSDB | |
| Soluble in cold (greater than or equal to 10mg/ml); Decomposes in hot (NTP, 1992) | decomposes | CAMEO |
Acetic Anhydride vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 4 mmHg | NIOSH | |
| 3.7503 mmHg | at 20 °C | ICSC | |
| 5.1004 mmHg | at 25 °C | HSDB |
Acetic Anhydride flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 48.89 °C (120 °F) | HSDB | |
| 49.44 °C (121 °F) | CAMEO |
Acetic Anhydride autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 316 °C (600.8 °F) | HSDB | |
| 330 °C (626 °F) | CAMEO |
Acetic Anhydride lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 2.7 % by volume | HSDB | |
| 2.9 % by volume | HSDB |
Acetic Anhydride upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 10.3 % by volume | HSDB |
Acetic Anhydride vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 3.5 (air = 1) | HSDB | |
| 3.52 (air = 1) | CAMEO |
Acetic Anhydride odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | 0.13 uL/L | HSDB | |
| Odor Low: 0.56 mg/cu m; Odor High: 1.44 mg/cu m; Sharp odor, sour acid | HSDB | ||
| Odor Threshold Low: 0.12 [ppm] | Haz-Map |
Acetic Anhydride critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 332.85 °C (631.1 °F) | HSDB |
Acetic Anhydride corrosivity
| Property | Value | Conditions | Source |
|---|---|---|---|
| Corrosivity | Corrosive | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Acetic Anhydride 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.
Acetic Anhydride fire potential
A fire and exposion hazard when exposed to heat or flame.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Acetic Anhydride storage and handling
Acetic Anhydride safe storage
Store only in original container. Separated from food and feedstuffs and incompatible materials. See Chemical Dangers. Fireproof. Dry.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Acetic Anhydride storage conditions
Store in cool, dry, well-ventilated location. Outside or detached storage is preferred. Store away from heat, oxidizers, and sunlight. Exclude moisture from vapor space in storage tanks.
Source: Hazardous Substances Data Bank (HSDB)
Acetic Anhydride incompatible materials
A violent reaction /acetic anhydride and glycerol/ occurs between these reactants in the presence of phosphorus oxychloride as a catalyst.
Source: Hazardous Substances Data Bank (HSDB)
Acetic Anhydride reactivity
ACETIC ANHYDRIDE reacts violently on contact with water, steam, methanol, ethanol, glycerol and boric acid. Reaction with water is particularly dangerous in presence with mineral acids (e.g., nitric, perchloric, chromic, sulfuric acid) [Chem. Eng. News 25, 3458]. Potentially explosive reactions with oxidizing reagents such as barium peroxide, chromium trioxide, chromic acid, hypochlorous acid, nitric acid, perchloric acid, peroxyacetic acid, potassium permanganate, hydrogen peroxide. [Sax, 9th ed., 1996, p. 15]. Reacts violently with metal nitrates used as nitrating agents [Davey W. et al., Chem. & Ind., 1948, p. 814].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Acetic Anhydride in the storage compatibility matrix →
11 · Transport
Acetic Anhydride 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.
Acetic Anhydride under UN 1715 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| ACETIC ANHYDRIDE | 8 | CF1 | II | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 8 is “Corrosive 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) |
|---|---|---|---|
| Acetic anhydride | 8 | II | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 8 is “Corrosive material” (49 CFR 173.2).
12 · Questions
Acetic Anhydride — frequently asked questions
What is the CAS number of Acetic Anhydride?
The CAS number of Acetic Anhydride is 108-24-7. Its EC number is 203-564-8.
What is the chemical formula of Acetic Anhydride?
The molecular formula of Acetic Anhydride is C4H6O3 and its molecular weight is 102.09 g/mol.
What does a Acetic Anhydride label have to show?
Under CLP Annex VI the label for Acetic Anhydride carries the pictograms Flame, Corrosion and Exclamation mark and the signal word is Danger.
Is Acetic Anhydride flammable?
Yes. CLP Annex VI assigns Acetic Anhydride H226 — flammable liquid and vapour. The flash point reported for it is 48.89 °C (120 °F) (HSDB).
Is Acetic Anhydride a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Acetic Anhydride. 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 Acetic Anhydride?
The US occupational exposure limit reported for Acetic Anhydride is 5.0 [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 Acetic Anhydride?
The boiling point reported for Acetic Anhydride is 139.5 °C (283.1 °F) (HSDB).
What is the melting point of Acetic Anhydride?
The melting point reported for Acetic Anhydride is -73.4 °C (-100.1 °F) (HSDB).
How should Acetic Anhydride be stored?
CLP Annex VI assigns Acetic Anhydride the storage statement P403. Store in cool, dry, well-ventilated location. Outside or detached storage is preferred. Store away from heat, oxidizers, and sunlight. Exclude moisture from vapor space in storage tanks. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Acetic Anhydride
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