Substance profile
Butyryl chloride
Butyryl chloride is a colorless liquid with a pungent acid chloride odor.
01 · Identification
What Butyryl chloride is
Butyryl chloride is a colorless liquid with a pungent acid chloride odor. Its molecular formula is C4H7ClO and its molecular weight is 106.55 g/mol. It boils at 102 °C, melts at -89 °C.
Under the GHS it carries the signal word Danger. It is classed as flammable agents - 3rd degree.
02 · Identifiers
Butyryl chloride identifiers and molecular data
Butyryl chloride CAS number and EC number
Butyryl chloride molecular formula and molecular weight
03 · GHS classification
Butyryl chloride hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Butyryl chloride pictograms and signal word
Butyryl chloride hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Flammable liquids GHS chapter 2.6 | Category 2 | H225 | GHS02 |
| 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.
Butyryl chloride hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H225 | Highly flammable liquid and vapour. |
| H314 | Causes severe skin burns and eye damage. |
This page lists only the codes assigned to Butyryl chloride. 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 Butyryl chloride
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 Butyryl chloride 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
Butyryl chloride precautionary statements
CLP Annex VI assigns 10 precautionary statements to Butyryl chloride. 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
Butyryl chloride 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 | бутирилхлорид |
| Spanish español | Cloruro de butirilo |
| Czech čeština | butyrylchlorid |
| Danish dansk | butyroylchlorid |
| German Deutsch | Butyrylchlorid Buttersäurechlorid |
| Estonian eesti | butürüülkloriid |
| Greek ελληνικά | βουτυρυλοχλωρίδιο |
| English English | butyryl chloride |
| French français | chlorure de butyryle |
| Croatian hrvatski | butiril-klorid |
| Italian italiano | butirrile cloruro |
| Latvian latviešu | butirilhlorīds |
| Lithuanian lietuvių | butirilchloridas |
| Hungarian magyar | butiril-klorid |
| Maltese Malti | klorur tal-butiril |
| Dutch Nederlands | butyrylchloride |
| Polish polski | chlorek butanoilu chlorek butyryluchlorek kwasu masłowego |
| Portuguese português | cloreto de butirilo |
| Romanian română | clorură de butiril |
| Slovak slovenčina | butanoylchlorid |
| Slovenian slovenščina | butiril klorid |
| Finnish suomi | butyryylikloridi |
| Swedish svenska | butyrylklorid |
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
Butyryl chloride GHS label elements
Everything CLP Annex VI fixes for Butyryl chloride, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Butyryl chloride
- Highly flammable liquid and vapour.
- 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.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- Immediately call a POISON CENTER/doctor/…
- 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 Butyryl chloride in the GHS label constructor →
07 · Health hazards
Butyryl chloride health hazards and exposure limits
Butyryl chloride hazard summary
Evolves HCl when spilled in water; [ERG 2016] A strong irritant; [HSDB] A severe skin, eye, and mucous membrane irritant; Inhalation may cause chemical pneumonitis and pulmonary edema; [CAMEO] A corrosive substance that can cause injury to the skin, eyes, and respiratory tract; Inhalation may cause edema and chemical pneumonitis; [MSDSonline]
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
08 · Physical and chemical properties
Butyryl chloride 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.
Butyryl chloride boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 102.22 °C (216 °F) | at 760 mmHg | CAMEO |
| 101.5 °C (214.7 °F) | range, midpoint shown | HSDB |
Butyryl chloride melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -89 °C (-128.2 °F) | HSDB | |
| -88.89 °C (-128 °F) | CAMEO |
Butyryl chloride density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.0263 g/cm³ | at 20.6 °C | HSDB |
| 1.0277 g/cm³ | at 20 °C | CAMEO |
Butyryl chloride solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Reaction (NTP, 1992) | CAMEO | |
| Dissolves slowly with decomposition in water | decomposes | HSDB | |
| Dissolves slowly with decomposition in alcohol; miscible with ether | decomposes | HSDB |
Butyryl chloride vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 30 mmHg | at 20 °C | HSDB |
| 41.7 mmHg | at 25 °C | HSDB | |
| 18.8 mmHg | at -2.22 °C | CAMEO |
Butyryl chloride flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 18 °C (64.4 °F) | HSDB | |
| 21.67 °C (71 °F) | CAMEO |
Butyryl chloride vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 3.67 (air = 1) | vapor specific gravity | HSDB |
Butyryl chloride corrosivity
| Property | Value | Conditions | Source |
|---|---|---|---|
| Corrosivity | Corrosive to metals | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Butyryl chloride 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.
Butyryl chloride fire potential
Flammable ... .
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Butyryl chloride storage and handling
Butyryl chloride storage conditions
Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Storage class (TRGS 510): Flammable liquids.
Source: Hazardous Substances Data Bank (HSDB)
Butyryl chloride incompatible materials
Incompatible materials: Alcohols, oxidizing agents, strong bases.
Source: Hazardous Substances Data Bank (HSDB)
Butyryl chloride reactivity
BUTYRYL CHLORIDE slowly dissolves in water with decomposition and formation of a weakly acidic solution. May react vigorously or explosively if mixed with diisopropyl ether or other ethers in the presence of trace amounts of metal salts [J. Haz. Mat., 1981, 4, 291].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Butyryl chloride in the storage compatibility matrix →
11 · Transport
Butyryl chloride 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.
Butyryl chloride under UN 2353 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| BUTYRYL CHLORIDE | 3 | FC | 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) |
|---|---|---|---|
| Butyryl chloride | 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
Butyryl chloride — frequently asked questions
What is the CAS number of Butyryl chloride?
The CAS number of Butyryl chloride is 141-75-3. Its EC number is 205-498-5.
What is the chemical formula of Butyryl chloride?
The molecular formula of Butyryl chloride is C4H7ClO and its molecular weight is 106.55 g/mol.
What does a Butyryl chloride label have to show?
Under CLP Annex VI the label for Butyryl chloride carries the pictograms Flame and Corrosion and the signal word is Danger.
Is Butyryl chloride flammable?
Yes. CLP Annex VI assigns Butyryl chloride H225 — highly flammable liquid and vapour. The flash point reported for it is 18 °C (64.4 °F) (HSDB).
Is Butyryl chloride a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Butyryl chloride. 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 boiling point of Butyryl chloride?
The boiling point reported for Butyryl chloride is 102.22 °C (216 °F), at 760 mmHg (CAMEO).
What is the melting point of Butyryl chloride?
The melting point reported for Butyryl chloride is -89 °C (-128.2 °F) (HSDB).
How should Butyryl chloride be stored?
CLP Annex VI assigns Butyryl chloride the storage statement P403. Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Storage class (TRGS 510): Flammable liquids. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Butyryl chloride
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