# Trans-2-trans-4-nonadiene

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> Markdown URL: https://additivefacts.com/additives/trans-2-trans-4-nonadiene.md

**Safety rating:** UNKNOWN
**CAS number:** 56700-78-8
**Category:** flavoring
**FDA GRAS:** no
**Adverse events (FDA AERS):** 0
**FDA recalls:** 0
**Last updated:** 2026-04-04

## Summary

Trans-2-trans-4-nonadiene (CAS 56700-78-8) is a synthetic flavoring agent used to impart fruity and vegetable-like sensory notes in food products. It is not currently approved as Generally Recognized as Safe (GRAS) by the FDA but has no documented adverse events or recalls associated with its use.

## Regulatory status

| Country | Status |
| --- | --- |
| United States | approved |
| European Union | not_evaluated |
| United Kingdom | approved |
| Canada | approved |
| Australia | approved |
| Japan | approved |
| South Korea | approved |
| Brazil | approved |
| China | approved |
| India | approved |

## Detailed analysis

## What is Trans-2-trans-4-Nonadiene?

Trans-2-trans-4-nonadiene is a synthetic organic compound belonging to the class of conjugated dienes—unsaturated hydrocarbons containing two double bonds separated by a single bond. With the CAS number 56700-78-8, this compound exists as a colorless to pale yellow liquid with characteristic fruity and vegetable-like aromatic properties. The trans configuration of its double bonds at positions 2 and 4 along a nine-carbon chain contributes to its specific sensory profile.

## Common Uses

This flavoring agent is primarily used in the food industry to enhance or create fruity flavors, particularly in beverages, confectionery, baked goods, and other processed foods where complex flavor notes are desired. The compound contributes melon, cucumber, and green vegetable-like characteristics to flavor compositions. Like other synthetic flavoring agents, it allows food manufacturers to achieve consistent flavor profiles and reduce reliance on natural flavor extracts, which can be variable in composition and cost.

## Safety Assessment

While trans-2-trans-4-nonadiene has not been formally established as GRAS by the FDA, there is limited but relevant safety data available. The compound has generated zero adverse event reports in FDA databases and has been associated with no recalls, suggesting that if used in food products, it has not triggered safety concerns in the post-market surveillance system. However, the lack of GRAS status indicates that comprehensive safety data may be limited or that formal FDA evaluation through the GRAS petition process has not been completed.

The safety profile of flavoring agents like this one typically involves assessment of acute toxicity, potential genotoxicity, and long-term exposure concerns. Conjugated diene compounds are generally metabolized through standard hepatic pathways, though individual compounds require specific evaluation. The chemical stability of trans-2-trans-4-nonadiene under various food storage and processing conditions is also relevant to safety assessment, as degradation products could theoretically differ in safety profile from the parent compound.

## Regulatory Status

Trans-2-trans-4-nonadiene does not currently hold GRAS status in the United States, which means it cannot be used in food products without prior FDA approval or a completed GRAS notification. In the European Union, this compound's regulatory status would fall under the Food Flavourings Regulation (EC 1334/2008), though specific approval status would require consultation of EFSA (European Food Safety Authority) evaluations.

Manufacturers wishing to use this additive would need to either submit a GRAS notification to the FDA or pursue a food additive petition for formal approval. The lack of GRAS status does not necessarily indicate safety concerns but rather indicates that the regulatory approval process has not been completed or that the compound may be restricted to specific regional markets with different regulatory frameworks.

## Key Studies

Direct peer-reviewed literature specifically evaluating trans-2-trans-4-nonadiene's safety is limited in public databases. Safety assessments for similar synthetic flavor compounds typically examine metabolic fate, potential for bioaccumulation, and genotoxic potential using standard toxicological protocols. The absence of adverse event reports and recalls suggests either limited use in food products or adequate safety margins in current applications.

Any organization considering use of this flavoring agent should consult with regulatory specialists and may need to commission or provide toxicological studies to support GRAS notification or food additive petition depending on intended market and use levels.

## Sources

- FDA Substances Added to Food (CFSAN)
- OpenFDA Adverse Event Reporting System (AERS)
- OpenFDA Food Recalls
- EFSA OpenFoodTox
- EU Food Additive Portal

## Citation

Additive Facts. "Trans-2-trans-4-nonadiene — Safety, regulation, and evidence." https://additivefacts.com/additives/trans-2-trans-4-nonadiene. Accessed 2026-05-20.