Substance profile
Isobutyric Acid
Isobutyric Acid is a colorless liquid with a pungent odor like that of butyric acid, but not as unpleasant.
01 · Identification
What Isobutyric Acid is
Isobutyric Acid is a colorless liquid with a pungent odor like that of butyric acid, but not as unpleasant. It boils at 154 °C, melts at -47 °C, is slightly soluble in water.
Under the GHS it carries the signal word Warning. It is classed as flammable agents - 2nd degree.
02 · Identifiers
Isobutyric Acid identifiers and molecular data
Isobutyric Acid CAS number and EC number
Isobutyric Acid molecular formula and molecular weight
03 · GHS classification
Isobutyric Acid hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Isobutyric Acid pictograms and signal word
Isobutyric Acid hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Acute toxicity - oral GHS chapter 3.1 | Category 4 | H302 | GHS07 |
| Acute toxicity - dermal GHS chapter 3.1 | Category 4 | H312 | GHS07 |
Isobutyric Acid hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H312 | Harmful in contact with skin. |
| H302 | Harmful if swallowed. |
This page lists only the codes assigned to Isobutyric Acid. 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 Isobutyric Acid
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 Isobutyric Acid 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
Isobutyric Acid precautionary statements
CLP Annex VI assigns 7 precautionary statements to Isobutyric Acid. 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
Isobutyric Acid 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 | изомаслена киселина |
| Spanish español | Ácido isobutírico |
| Czech čeština | isomáselná kyselina |
| Danish dansk | isosmørsyre |
| German Deutsch | Isobuttersäure Methylpropansäure |
| Estonian eesti | isovõihape |
| Greek ελληνικά | ισοβουτυρικό οξύ |
| English English | isobutyric acid |
| French français | acide isobutyrique |
| Croatian hrvatski | izomaslačna kiselina |
| Italian italiano | acido isobutirrico |
| Latvian latviešu | izosviestskābe |
| Lithuanian lietuvių | izobutano rūgštis |
| Hungarian magyar | izovajsav |
| Maltese Malti | aċidu isobutiriku |
| Dutch Nederlands | isoboterzuur |
| Polish polski | kwas izomasłowy |
| Portuguese português | ácido isobutírico |
| Romanian română | acid izobutiric |
| Slovak slovenčina | kyselina 2-metylpropánová |
| Slovenian slovenščina | izomaslena kislina |
| Finnish suomi | isovoihappo |
| Swedish svenska | isosmörsyra |
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
Isobutyric Acid GHS label elements
Everything CLP Annex VI fixes for Isobutyric Acid, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Warning
Isobutyric Acid
- Harmful in contact with skin.
- Harmful if swallowed.
- Do not eat, drink or smoke when using this product.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- IF ON SKIN:
- Call a POISON CENTER/doctor/… if you feel unwell.
- Rinse mouth.
- Wash with plenty of water/…
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Isobutyric Acid in the GHS label constructor →
07 · Health hazards
Isobutyric Acid health hazards and exposure limits
Isobutyric Acid hazard summary
A strong skin and eye irritant; Emergency treatment: irritants; [HSDB] A corrosive substance that can cause injury to the skin, eyes, and respiratory tract; [ICSC] A corrosive substance; Inhalation may cause chemical pneumonitis; Can be absorbed through skin; [MSDSonline]
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
08 · Physical and chemical properties
Isobutyric Acid 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.
Isobutyric Acid boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 153.89 °C (309 °F) | at 760 mmHg | CAMEO |
| 155 °C (311 °F) | JECFA | ||
| 153.5 °C (308.3 °F) | range, midpoint shown, at 760 mmHg | HSDB |
Isobutyric Acid melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -47 °C (-52.6 °F) | HSDB | |
| -46.11 °C (-51 °F) | CAMEO |
Isobutyric Acid density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.95 g/cm³ | ICSC | |
| 0.95 g/cm³ | at 20 °C | HSDB | |
| 0.949 g/cm³ | at 20 °C | CAMEO |
Isobutyric Acid solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Slightly soluble in carbon tetrachloride | HSDB | |
| Sol in 6 parts of water; miscible with alcohol, chloroform, and ether. | HSDB | ||
| In water, 1.67X10+5 mg/L at 20 °C | at 20 °C | HSDB |
Isobutyric Acid vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 1.81 mmHg | at 25 °C | HSDB |
| 0.9751 mmHg | at 14.7 °C | ICSC | |
| 1 mmHg | at 14.7 °C | DOE PAC |
Isobutyric Acid flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 76.67 °C (170 °F) | HSDB | |
| 55.56 °C (132 °F) | HSDB |
Isobutyric Acid autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 501.67 °C (935 °F) | HSDB | |
| 481 °C (897.8 °F) | ICSC |
Isobutyric Acid lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 2 % by volume | HSDB |
Isobutyric Acid upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 9.2 % by volume | HSDB | |
| 9 % by volume | ICSC |
Isobutyric Acid vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 3 (air = 1) | HSDB |
Isobutyric Acid odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | Odor detection threshold in water: 8.1 ppm. | HSDB | |
| Aroma threshold values: Detection: 10 ppb to 9.5 ppm. | HSDB | ||
| It has a stench odor. | HSDB |
Isobutyric Acid critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 336.11 °C (637 °F) | HSDB |
Isobutyric Acid corrosivity
| Property | Value | Conditions | Source |
|---|---|---|---|
| Corrosivity | /2-Methylpropanoic acid/ is corrosive to metals. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Isobutyric Acid 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.
Isobutyric Acid fire potential
/2-Methylpropanoic acid/ is combustible.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Isobutyric Acid storage and handling
Isobutyric Acid safe storage
Fireproof. Separated from strong bases and food and feedstuffs.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Isobutyric Acid incompatible materials
2-Methylpropanoic acid can react with oxidizing materials.
Source: Hazardous Substances Data Bank (HSDB)
Isobutyric Acid reactivity
ISOBUTYRIC ACID corrodes aluminum and other metals. Flammable hydrogen gas may accumulate in enclosed spaces in which this reaction has taken place (USCG, 1999).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Isobutyric Acid in the storage compatibility matrix →
11 · Transport
Isobutyric Acid 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.
Isobutyric Acid under UN 2529 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| ISOBUTYRIC ACID | 3 | FC | III | |
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) |
|---|---|---|---|
| Isobutyric acid | 3 | III | |
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
Isobutyric Acid — frequently asked questions
What is the CAS number of Isobutyric Acid?
The CAS number of Isobutyric Acid is 79-31-2. Its EC number is 201-195-7.
What does a Isobutyric Acid label have to show?
Under CLP Annex VI the label for Isobutyric Acid carries the pictogram Exclamation mark and the signal word is Warning.
Is Isobutyric Acid flammable?
CLP Annex VI assigns Isobutyric Acid no flammability hazard class. That is not a statement that it cannot burn: the harmonised list only records the hazards that were assessed for it. The flash point reported for it is 76.67 °C (170 °F) (HSDB).
Is Isobutyric Acid a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Isobutyric Acid. 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 Isobutyric Acid?
The boiling point reported for Isobutyric Acid is 153.89 °C (309 °F), at 760 mmHg (CAMEO).
What is the melting point of Isobutyric Acid?
The melting point reported for Isobutyric Acid is -47 °C (-52.6 °F) (HSDB).
Nearby
Substances next to Isobutyric Acid
Keep going: substances starting with I, or search the whole database by name, CAS number, pictogram or signal word.