Flavor ingredient regulatory record
trans-2-Methyl-2-butenoic acid
trans-2-Methyl-2-butenoic acid is an acid in the fruity family, FEMA GRAS under FEMA number 3599 (CAS 80-59-1). Its odor is fruity, tart, berry, green, floral.
- FEMA
- 3599
- CAS
- 80-59-1
- JECFA
- 1205
- EU FL
- 08.064
- Formula
- C5H8O2
- EC
- 201-295-0
GRAS status: FEMA GRAS, publication 12. Recorded by FDA in the Substances Added to Food inventory under CAS 80-59-1.
Structure
Identity
Also known as: 2-Butenoic acid, 2-methyl-, (2E)-, Crotonic acid, 2-methyl-, (E)-, Tiglic acid, 2-Butenoic acid, 2-methyl-, (E)-, (2E)-2-Methyl-2-butenoic acid, Cevadic acid, trans-α,β-Dimethylacrylic acid, trans-2,3-Dimethylacrylic acid, trans-2-Methylcrotonic acid, (E)-2-Methylcrotonic acid, Tiglinic acid, (E)-2,3-Dimethylacrylic acid.
Can trans-2-Methyl-2-butenoic acid be labeled natural?
The process decides for trans-2-Methyl-2-butenoic acid. It occurs in nature, so a natural-source, natural-process material is natural flavor in the US and synthetic trans-2-Methyl-2-butenoic acid is artificial. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic trans-2-Methyl-2-butenoic acid 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
trans-2-Methyl-2-butenoic acid is FEMA GRAS under FEMA number 3599. 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 08.064, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.
JECFA (WHO / FAO)
JECFA number 1205, evaluated at the 61st meeting in 2003. no safety concern at current levels of intake.
Other US flags
Not on the California Proposition 65 list.
TSCA Inventory status
A flavor ingredient is also an industrial chemical. trans-2-Methyl-2-butenoic acid appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 80-59-1, where EPA names it 2-Butenoic acid, 2-methyl-, (2E)-.
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, tart, berry, green, floral.
Where it is used
trans-2-Methyl-2-butenoic acid is used in beverage, confection, fruit flavors, sauces and dressings, typically as a fruity note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to trans-2-Methyl-2-butenoic acid by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| 2-Methylbutyric acid | 2695 | 94% | In nature |
| 2-Ethylbutyric acid | 2429 | 81% | In nature |
| Isobutyric acid | 2222 | 81% | In nature |
| 2-Oxobutyric acid | 3723 | 80% | In nature |
| 2-Methyl-2-pentenoic acid | 3195 | 79% | In nature |
More acids in this index
4-Ethyloctanoic acid · 3-Methyl-2-oxopentanoic acid · cis-4-(2,2,3-Trimethylcyclopentyl)butanoic acid · Levulinic acid · 5&6-Decenoic acid · Cyclohexanecarboxylic acid
trans-2-Methyl-2-butenoic acid FAQ
Is trans-2-Methyl-2-butenoic acid on the FEMA GRAS list?
It is. FEMA number 3599 covers trans-2-Methyl-2-butenoic acid. The Code of Federal Regulations lists it at 21 CFR 172.515.
What is the FEMA number for trans-2-Methyl-2-butenoic acid?
The FEMA number for trans-2-Methyl-2-butenoic acid is 3599 and its CAS registry number is 80-59-1. Its flavor category is fruity.
What is trans-2-Methyl-2-butenoic acid used for?
trans-2-Methyl-2-butenoic acid is described as fruity, tart, berry, green, floral. It shows up in beverage, confection, fruit flavors, sauces and dressings.
What did JECFA conclude about trans-2-Methyl-2-butenoic acid?
JECFA evaluated trans-2-Methyl-2-butenoic acid at the 61st meeting in 2003 under JECFA number 1205. The panel concluded: no safety concern at current levels of intake.
Is trans-2-Methyl-2-butenoic acid approved in the EU?
Yes. FL 08.064 is the Union List entry for trans-2-Methyl-2-butenoic acid, annex I Part A, under Regulation 1334/2008, and the UK keeps the same list.
Is trans-2-Methyl-2-butenoic acid natural or artificial?
Nature makes trans-2-Methyl-2-butenoic acid, which is why the US label turns on process. A natural route gives natural flavor; synthesis gives artificial trans-2-Methyl-2-butenoic acid, same molecule. The EU and UK grant the natural claim only to that natural route; Mercosur and Mexico call synthetic material identical-to-natural.
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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 TRANS-2-METHYL-2-BUTENOIC ACID under CAS 80-59-1 and carries its FEMA number, its JECFA flavor number. 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.