Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

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Substance profile

Isobutyric Acid

Isobutyric Acid is a colorless liquid with a pungent odor like that of butyric acid, but not as unpleasant.

CAS 79-31-2 Warning

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.

CAS number79-31-2
EC number201-195-7
Index number607-063-00-9
Chemical class Flammable agents - 2nd degree

02 · GHS classification

Hazards and label elements

Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.

Signal wordWarning
Hazard statements assigned to Isobutyric Acid
CodeHazard statement
H312 Harmful in contact with skin.
H302 Harmful if swallowed.

Precautionary statements: P270, P280, P301, P302, P312, P330, P352

03 · 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.

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
Melting point -47 °C (-52.6 °F) HSDB
-46.11 °C (-51 °F) CAMEO
Density 0.95 g/cm³ ICSC
0.95 g/cm³ at 20 °C HSDB
0.949 g/cm³ at 20 °C CAMEO
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
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
Flash point 76.67 °C (170 °F) HSDB
55.56 °C (132 °F) HSDB
Autoignition temperature 501.67 °C (935 °F) HSDB
481 °C (897.8 °F) ICSC
Lower explosive limit (LEL) 2 % by volume HSDB
Upper explosive limit (UEL) 9.2 % by volume HSDB
9 % by volume ICSC
Vapor density 3 (air = 1) HSDB
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
Critical temperature and pressure 336.11 °C (637 °F) HSDB
Corrosivity /2-Methylpropanoic acid/ is corrosive to metals. HSDB

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

04 · Handling and storage

Storing and handling Isobutyric Acid

Incompatible materials

2-Methylpropanoic acid can react with oxidizing materials.

Source: Hazardous Substances Data Bank (HSDB)

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 →

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