In short
Isoamyl butyrate is a fruity ester with a sweet banana-pear odour. It occurs in banana and other fruits and gives a ripe, rounded fruitiness.
What Isoamyl Butyrate smells like
Isoamyl butyrate has a strong, characteristic, fruity, pear-like odour and a sweet taste, which one source finds stronger than the acetate's. A perfumery description gives a powerful, diffusive, fruity, sweet apricot-banana-pineapple odour, somewhat sharper than isoamyl isobutyrate.
- Leading note
- Sweet pear and banana
- Supporting facets
- Apricot, pineapple
- Character
- Sweet, fruity, diffusive
What makes Isoamyl Butyrate distinctive
A broader fruit than isoamyl acetate: pear and banana with apricot and pineapple.
How Isoamyl Butyrate is used
Used in fruity top notes and in pear, banana and tropical flavours.
Typical role: modifier (used in small amounts to change the character of a blend).
How Isoamyl Butyrate differs from similar materials
- Isoamyl Acetate
- Isoamyl acetate is the classic banana and pear drop; the butyrate is fruitier, with apricot and pineapple, and stronger in taste.
Each difference compares the published descriptions of the two materials. Smell varies with grade, supplier and dilution; compare them side by side on blotters before substituting one for another.
Identity and classification
- Type
- Aroma chemical
- Origin
- Occurs in nature
- Odour family
- Fruity
- Note position
- Top note
- Physical form at room temperature
- Liquid
- Also known as
- Isopentyl butanoate
- CAS number
- 106-27-4
- Molecular formula
- C9H18O2
- Molecular weight
- 158.24 g/mol
- IUPAC name
- 3-methylbutyl butanoate
The CAS number, formula and molecular weight are taken from PubChem compound 7795, whose own record lists this CAS number; checked 19 October 2026.
Safety and compliance
Hazard classification of the neat substance, as PubChem summarises it, read 26 October 2026. Companies notifying the ECHA C&L Inventory classify it (1,927 reports): H226 flammable liquid and vapor (98.6% of reports); H412 harmful to aquatic life with long lasting effects (94.3% of reports). Unless it is harmonised, this is the notifiers' own classification, not a binding one.
This page is general information, not a safety assessment or a specification. Confirm identity, composition, IFRA status and allergen content from your supplier's documents for the lot you hold.
Materials it works with
-
Isoamyl Acetate
Aroma chemical · Fruity / Gourmand — banana, pear drop, fruity, sweet
-
Hexyl Acetate
Aroma chemical · Fruity / Green — pear, apple, fruity, green
-
Ethyl Butyrate
Aroma chemical · Fruity / Gourmand — pineapple, fruity, sweet
-
Prenyl Acetate
Aroma chemical · Fruity / Green — fruity, banana, pear, green
Used in formulas and accords
Not currently used in any published formula.
The Formula & Accord Library lists Isoamyl Butyrate here as soon as a published formula, accord or base uses it.
Further reading
Questions about Isoamyl Butyrate
Is Isoamyl Butyrate natural or synthetic?
The molecule occurs in nature. Commercial Isoamyl Butyrate may be made by synthesis or obtained from natural sources, so check the supplier's specification if the distinction matters to you.
What is the CAS number of Isoamyl Butyrate?
106-27-4. It was checked against PubChem on 19 October 2026.
Sources
- PubChem — compound 7795, checked 19 October 2026.
- PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 26 October 2026.
- The Good Scents Company — isoamyl butyrate — odour database.
- ChemicalBook — isoamyl butyrate (CAS 106-27-4) — odour database.
- Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 20 October 2026. Evidence: more than one published description. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.