Substance profile
Butyraldehyde
Butyraldehyde is a liquid with a characteristic, pungent, aldehyde odor.
01 · Identification
What Butyraldehyde is
Butyraldehyde is a liquid with a characteristic, pungent, aldehyde odor. Its molecular formula is C4H8O and its molecular weight is 72.11 g/mol. It boils at 74.8 °C, melts at -96.9 °C.
Under the GHS it carries the signal word Danger. It is classed as flammable agents - 3rd degree.
02 · Identifiers
Butyraldehyde identifiers and molecular data
Butyraldehyde CAS number and EC number
Butyraldehyde molecular formula and molecular weight
03 · GHS classification
Butyraldehyde hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Butyraldehyde pictograms and signal word
Butyraldehyde hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Flammable liquids GHS chapter 2.6 | Category 2 | H225 | GHS02 |
Butyraldehyde hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H225 | Highly flammable liquid and vapour. |
This page lists only the codes assigned to Butyraldehyde. 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 Butyraldehyde
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 Butyraldehyde 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
Butyraldehyde precautionary statements
CLP Annex VI assigns 5 precautionary statements to Butyraldehyde. 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.
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
Butyraldehyde 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 | бутиралдехид |
| Spanish español | Butiraldehído |
| Czech čeština | butyraldehyd |
| Danish dansk | butyraldehyd |
| German Deutsch | Butyraldehyd Butanal |
| Estonian eesti | butüüraldehüüd |
| Greek ελληνικά | βουτυραλδεΰδη |
| English English | butyraldehyde |
| French français | butyraldéhyde |
| Croatian hrvatski | butiraldehid |
| Italian italiano | aldeide butirrica butirraldeide |
| Latvian latviešu | butiraldehīds |
| Lithuanian lietuvių | butiraldehidas |
| Hungarian magyar | butiraldehid |
| Maltese Malti | butiraldeid |
| Dutch Nederlands | butyraldehyde |
| Polish polski | butanal aldehyd masłowy |
| Portuguese português | butiraldeído |
| Romanian română | butiraldehidă |
| Slovak slovenčina | butyraldehyd |
| Slovenian slovenščina | butiraldehid |
| Finnish suomi | butyyrialdehydi |
| Swedish svenska | butyraldehyd |
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
Butyraldehyde GHS label elements
Everything CLP Annex VI fixes for Butyraldehyde, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Butyraldehyde
- Highly flammable liquid and vapour.
- 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.
- Store in a well-ventilated place.
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Butyraldehyde in the GHS label constructor →
07 · Health hazards
Butyraldehyde health hazards and exposure limits
Butyraldehyde hazard summary
If left on clothing, can cause reddening of skin; [CHRIS] Butyraldehyde is a skin irritant. [Quick CPC] May form explosive peroxides; May polymerize; A skin, eye, and respiratory tract irritant; [ICSC] May cause burns to skin and eyes; Inhalation may cause spasm, edema of the larynx and bronchi, chemical pneumonitis, and pulmonary edema; [HSDB] A severe irritant in animal experiments; In subchronic inhalation studies, 50 ppm was the no-observable-effect level and 117 ppm produced eye and upper respiratory tract irritation; Caused anesthetic effects in lethal concentration studies; [OECD SIDS] See ALDEHYDES.
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Butyraldehyde carcinogenicity classification
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.
08 · Physical and chemical properties
Butyraldehyde 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.
Butyraldehyde boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 74.8 °C (166.6 °F) | HSDB | |
| 75 °C (167 °F) | at 760 mmHg | CAMEO |
Butyraldehyde melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -96.86 °C (-142.3 °F) | HSDB | |
| -98.89 °C (-146 °F) | CAMEO | ||
| -99 °C (-146.2 °F) | ICSC |
Butyraldehyde density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.8016 g/cm³ | HSDB | |
| 0.8 g/cm³ | ICSC | ||
| 0.803 g/cm³ | at 20 °C | CAMEO |
Butyraldehyde solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Miscible with ethanol, ether, ethyl acetate, acetone, toluene, many other organic solvents andoils | HSDB | |
| Soluble in water; miscible with ethanol; very olubl ein acetone, benzene; slightly soluble in chloroform | HSDB | ||
| In water, 7.10X10+4 mg/L at 25 °C | at 25 °C | HSDB |
Butyraldehyde vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 91.5 mmHg | at 20 °C | CAMEO |
| 91.5075 mmHg | at 20 °C | ICSC | |
| 111 mmHg | at 25 °C | HSDB |
Butyraldehyde flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | -22.22 °C (-8 °F) | HSDB | |
| -6.67 °C (20 °F) | CAMEO | ||
| -12 °C (10.4 °F) | ICSC |
Butyraldehyde autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 218.33 °C (425 °F) | HSDB | |
| 230 °C (446 °F) | CAMEO |
Butyraldehyde lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 1.9 % by volume | HSDB | |
| 2.5 % by volume | CAMEO |
Butyraldehyde upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 12.5 % by volume | HSDB |
Butyraldehyde vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 2.5 (air = 1) | HSDB |
Butyraldehyde odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | Odor threshold= 0.009 ppm | HSDB | |
| Odor Threshold Low: 0.005 [ppm] | Haz-Map | ||
| Odor Threshold High: 9.0 [ppm] | Haz-Map |
Butyraldehyde critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 263.95 °C (507.1 °F) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Butyraldehyde 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.
Butyraldehyde fire potential
Highly flammable liquid.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Butyraldehyde storage and handling
Butyraldehyde peroxide formation
D*: Other compounds that may form peroxides
Source: Lab and Research Safety, University of Minnesota
Butyraldehyde safe storage
Fireproof. Separated from incompatible materials. See Chemical Dangers. Cool. Keep in the dark. Store in an area without drain or sewer access.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Butyraldehyde storage conditions
On contact with air butyraldehyde is oxidized readily to the butyric acids. Therefore, storage under inert gas is mandatory.
Source: Hazardous Substances Data Bank (HSDB)
Butyraldehyde incompatible materials
Incompatible with oxidizing materials.
Source: Hazardous Substances Data Bank (HSDB)
Butyraldehyde reactivity
A colorless liquid, BUTYRALDEHYDE can react with oxidizing materials. In contact with strong acids or bases it will undergo an exothermic condensation reaction. The dry aldehyde may undergo some polymerization reaction. Reacts vigorously with chlorosulfonic acid, nitric acid, sulfuric acid (oleum). [Sax, 9th ed., 1996, p. 607].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Butyraldehyde in the storage compatibility matrix →
11 · Transport
Butyraldehyde 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.
Butyraldehyde under UN 1129 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| BUTYRALDEHYDE | 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) |
|---|---|---|---|
| Butyraldehyde | 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
Butyraldehyde — frequently asked questions
What is the CAS number of Butyraldehyde?
The CAS number of Butyraldehyde is 123-72-8. Its EC number is 204-646-6.
What is the chemical formula of Butyraldehyde?
The molecular formula of Butyraldehyde is C4H8O and its molecular weight is 72.11 g/mol.
What does a Butyraldehyde label have to show?
Under CLP Annex VI the label for Butyraldehyde carries the pictogram Flame and the signal word is Danger.
Is Butyraldehyde flammable?
Yes. CLP Annex VI assigns Butyraldehyde H225 — highly flammable liquid and vapour. The flash point reported for it is -22.22 °C (-8 °F) (HSDB).
Is Butyraldehyde a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Butyraldehyde. 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 2B: possibly carcinogenic to humans.
What is the boiling point of Butyraldehyde?
The boiling point reported for Butyraldehyde is 74.8 °C (166.6 °F) (HSDB).
What is the melting point of Butyraldehyde?
The melting point reported for Butyraldehyde is -96.86 °C (-142.3 °F) (HSDB).
How should Butyraldehyde be stored?
CLP Annex VI assigns Butyraldehyde the storage statement P403. On contact with air butyraldehyde is oxidized readily to the butyric acids. Therefore, storage under inert gas is mandatory. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Butyraldehyde
Keep going: substances starting with B, or search the whole database by name, CAS number, pictogram or signal word.