Flavor ingredient regulatory record
Isobutyl acetate
Isobutyl acetate is an ester in the fruity family, FEMA GRAS under FEMA number 2175 (CAS 110-19-0). Its odor is fruity, apple, banana, ethereal.
- FEMA
- 2175
- CAS
- 110-19-0
- JECFA
- 137
- EU FL
- 09.005
- Formula
- C6H12O2
- EC
- 203-745-1
GRAS status: FEMA GRAS, publication 3. Recorded by FDA in the Substances Added to Food inventory under CAS 110-19-0.
Structure
Identity
Also known as: Acetic acid, 2-methylpropyl ester, Acetic acid, isobutyl ester, β-Methylpropyl ethanoate, 2-Methylpropyl acetate, NSC 8035, 2-methylpropyl acetate, isobutyl ethanoate, 2-methylpropyl ethanoate, acetic acid, 2-methylpropyl ester, 2-methyl-1-propyl acetate, acetic acid, isobutyl ester, acetate d'isobutyle.
Can Isobutyl acetate be labeled natural?
The process decides for isobutyl acetate. It occurs in nature, so a natural-source, natural-process material is natural flavor in the US and synthetic isobutyl acetate is artificial. The EU and UK grant the natural claim only to that natural route; Mercosur and Mexico call synthetic material identical-to-natural.
- United States
- Natural or artificial, by process
- European Union and UK
- Natural only from natural material
- Mercosur and Mexico
- Natural or identical-to-natural
How each market defines the classes: natural vs artificial flavor under 21 CFR 101.22.
Regulatory status, with citations
United States
Isobutyl acetate is FEMA GRAS under FEMA number 2175. It is cited in the Code of Federal Regulations at 21 CFR 172.515.
European Union and United Kingdom
Listed on the Union List of flavouring substances as FL 09.005, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (JECFA). The UK retains the same list.
JECFA (WHO / FAO)
JECFA number 137, evaluated at the 49th meeting in 1997. No safety concern at current levels of intake when used as a flavouring agent.
Other US flags
Not on the California Proposition 65 list. Listed on the EPA TSCA inventory.
TSCA Inventory status
A flavor ingredient is also an industrial chemical. Isobutyl acetate appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 110-19-0, where EPA names it Acetic acid, 2-methylpropyl ester.
Active in US commerce
EPA designates this substance active, so no Notice of Activity Form B is required before manufacturing. What active and inactive mean.
EPA publishes no regulatory flags on this listing. What the flags mean.
From the EPA non-confidential TSCA Inventory, July 2026 release. EPA also maintains a confidential portion it does not publish. Search the Inventory by CAS number.
Odor and taste
Odor: Fruity, apple, banana, ethereal.
Taste: Fruity, apple, sweet.
Where it is used
Isobutyl acetate is used in apple, banana and fruit, typically as a fruity note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to Isobutyl acetate by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| 5-Methyl-3-hexen-2-one | 3409 | 92% | In nature |
| Propyl acetate | 2925 | 89% | In nature |
| 3-Oxobutanal dimethyl acetal | 3381 | 81% | In nature |
| 4-Methylpentanoic acid | 3463 | 75% | In nature |
More esters in this index
Methyl linolenate · Ethyl trans-2-cis-4-decadienoate · Phenethyl formate · Phenethyl propionate · Ethyl formate · cis-3-Hexenyl cis-3-hexenoate
Isobutyl acetate FAQ
Is isobutyl acetate FEMA GRAS?
Yes. The FEMA Expert Panel lists isobutyl acetate as GRAS under FEMA number 2175. The Code of Federal Regulations lists it at 21 CFR 172.515.
What are the FEMA and CAS numbers for isobutyl acetate?
Isobutyl acetate is FEMA 2175, CAS 110-19-0. Its flavor category is fruity.
How is isobutyl acetate described, and where does it show up?
Flavorists describe isobutyl acetate as fruity, apple, banana, ethereal. On the palate it is fruity, apple, sweet. It is used in apple, banana and fruit.
What did JECFA conclude about isobutyl acetate?
JECFA evaluated isobutyl acetate at the 49th meeting in 1997 under JECFA number 137. The panel concluded: No safety concern at current levels of intake when used as a flavouring agent.
Is isobutyl acetate on the EU Union List?
Yes. FL 09.005 is the Union List entry for isobutyl acetate, annex I Part A, under Regulation 1334/2008, and the UK keeps the same list.
Does isobutyl acetate count as natural in the US and the EU?
Nature makes isobutyl acetate, which is why the US label turns on process. A natural route gives natural flavor; synthesis gives artificial isobutyl acetate, same molecule. In the EU and UK the natural claim likewise needs the natural route, while Mercosur and Mexico keep a third class, identical-to-natural, for the synthetic material.
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Guides: What Is FEMA GRAS? · Natural vs artificial · Filing a GRAS notification
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Sources and attribution. The identity and regulatory facts on this page are taken from the FDA Substances Added to Food inventory, a US government record, which lists this substance as ISOBUTYL ACETATE under CAS 110-19-0 and carries its FEMA number, its JECFA flavor number and its 21 CFR citations. The inventory is searchable at FDA. FDA records its technical effect as flavoring agent or adjuvant.
A FEMA GRAS conclusion is reached by the Expert Panel of the Flavor and Extract Manufacturers Association of the United States, and the FEMA number names that conclusion. FEMA publishes its own entry for this substance in the FEMA Flavor Library, which is the authoritative record of what the Panel decided and is worth reading alongside this page.
Ambrose Compliance is not affiliated with, endorsed by, or sponsored by FEMA. FEMA and FEMA GRAS are used here as identifiers for a published regulatory determination, not as marks of any relationship between FEMA and Ambrose.
About this page. Facts come from the FDA Substances Added to Food inventory, the Code of Federal Regulations, the EPA TSCA Inventory, the EU Union List, JECFA and the Ambrose database, with FEMA's published determination cited where it applies; parts of the text are written by Ambrose AI, which can make mistakes. Check the cited source before relying on anything here. This is not regulatory or legal advice.