# Ethyl 3-(methylthio)butyrate

> Source URL: https://additivefacts.com/additives/ethyl-3-methylthio-butyrate
> Markdown URL: https://additivefacts.com/additives/ethyl-3-methylthio-butyrate.md

**Safety rating:** UNKNOWN
**CAS number:** 233665-96-8
**Category:** flavoring
**FDA GRAS:** no
**Adverse events (FDA AERS):** 0
**FDA recalls:** 0
**Last updated:** 2026-04-02

## Summary

Ethyl 3-(methylthio)butyrate is a synthetic flavoring compound that provides meaty, savory, and sulfur-containing aromatic notes to food products. It is used in limited quantities as a flavoring agent in processed foods to enhance taste profiles.

## Regulatory status

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

## Detailed analysis

## What is Ethyl 3-(methylthio)butyrate?

Ethyl 3-(methylthio)butyrate is a synthetic organic compound classified as a flavoring agent. It belongs to the family of sulfur-containing volatile compounds that contribute savory and meaty aromatic characteristics to foods. The compound has the CAS number 233665-96-8 and is composed of a butyrate ester backbone with a methylthio (sulfur-containing) substituent.

## Common Uses

This flavoring agent is used in the food industry to enhance savory notes in processed food products. Its primary applications include meat analogs, savory snacks, processed meat products, soups, broths, and savory seasoning blends. The compound's sulfurous character makes it particularly valuable in products designed to replicate or enhance meaty flavors. Like most synthetic flavoring agents, it is used in very small quantities—typically in the parts per million (ppm) range—to achieve the desired flavor impact without imparting off-flavors.

## Safety Assessment

Ethyl 3-(methylthio)butyrate has not received FDA GRAS (Generally Recognized As Safe) status. However, the absence of GRAS designation does not indicate a safety concern; rather, it reflects that formal GRAS evaluation has not been completed or submitted to the FDA. The compound has generated zero reported adverse events in FDA surveillance systems and has not been subject to any FDA recalls, indicating no known safety incidents in commercial use.

The safety profile of synthetic flavoring agents is generally established through toxicology studies examining acute toxicity, genotoxicity, and potential reproductive or developmental effects. Many sulfur-containing flavoring compounds have demonstrated acceptable safety margins when used at typical flavoring levels. However, specific published safety studies for this particular compound are limited in the public domain.

## Regulatory Status

In the United States, flavoring agents not granted GRAS status may still be used under FDA regulations when they meet the definition of food additives and are used in accordance with FDA guidelines. The compound's regulatory pathway and approval status vary by country. Some jurisdictions may list this compound in their flavoring regulations, while others require specific approval documentation.

The European Food Safety Authority (EFSA) and other international regulatory bodies maintain different frameworks for flavoring agent evaluation. Manufacturers using this additive must ensure compliance with regulations in all markets where their products are sold.

## Key Studies

Published independent safety data specifically on ethyl 3-(methylthio)butyrate is limited in peer-reviewed literature. Safety evaluations for similar sulfur-containing flavoring compounds have generally supported their use at levels typical in food applications. The body of evidence for structurally related compounds suggests that proper use levels present minimal safety concerns.

Manufacturers typically conduct proprietary toxicology studies to support regulatory submissions and compliance with local food safety regulations. These studies may not be publicly available but inform the risk assessment process. The absence of adverse event reports and recalls provides empirical support for the safety of current commercial use patterns.

Standardized safety testing protocols for flavoring agents, as outlined by regulatory agencies and industry organizations, typically address acute and subchronic toxicity. For volatile flavoring compounds used in minimal quantities, the margin of safety is generally wide when used as intended.

## 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. "Ethyl 3-(methylthio)butyrate — Safety, regulation, and evidence." https://additivefacts.com/additives/ethyl-3-methylthio-butyrate. Accessed 2026-05-19.