# 3-mercaptohexanol

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> Markdown URL: https://additivefacts.com/additives/3-mercaptohexanol.md

**Safety rating:** SAFE
**CAS number:** 51755-83-0
**Category:** flavoring
**FDA GRAS:** no
**Adverse events (FDA AERS):** 0
**FDA recalls:** 0
**Last updated:** 2026-04-02

## Summary

3-mercaptohexanol is a volatile organic compound used as a flavoring agent to impart fruity and wine-like sensory characteristics to food and beverage products. It occurs naturally in some fruits and is synthesized for use in the flavor industry.

## 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 3-mercaptohexanol?

3-mercaptohexanol (CAS Number: 51755-83-0) is a volatile organic compound belonging to the class of thiols—molecules containing a sulfhydryl (-SH) functional group. It is a colorless to pale yellow liquid with a characteristic fruity, wine-like aroma. The compound occurs naturally in trace amounts in certain fruits, particularly grapes and stone fruits, where it contributes to their distinctive sensory profiles. For commercial food applications, 3-mercaptohexanol is synthesized chemically to ensure consistency, purity, and supply reliability.

## Common Uses

3-mercaptohexanol is primarily used as a flavoring agent and flavor adjuvant in the food and beverage industry. Its applications include:

- **Alcoholic beverages**: Wine and spirits production, where it enhances fruity and varietal character
- **Non-alcoholic beverages**: Fruit juices, juice drinks, and flavored water products
- **Dairy products**: Yogurts and flavored milk beverages
- **Confectionery and baked goods**: Where fruity flavor notes are desired
- **Savory applications**: Limited use in certain prepared foods requiring complex flavor profiles

The compound is used at very low concentrations—typically measured in parts per billion to parts per million—due to its potent sensory impact. This low-use level is characteristic of modern flavoring compounds that deliver significant flavor impact at minimal amounts.

## Safety Assessment

Limited published safety data exists specifically for 3-mercaptohexanol in scientific literature. However, the compound shares structural characteristics with other thiol-containing compounds that have been evaluated for safety. As a volatile flavor component used at extremely low concentrations, systemic exposure through food consumption is expected to be minimal.

No adverse events have been reported to the FDA in association with this additive. Additionally, no FDA recalls involving 3-mercaptohexanol have been documented. The absence of reported adverse effects in the context of decades of use in flavor applications suggests it does not pose significant acute safety concerns at typical use levels.

The compound undergoes rapid metabolic degradation in the body, similar to other volatile flavor components. Its thiol functional group is metabolized through standard hepatic pathways. The low concentrations used in food products mean that systemic exposure is far below levels that would be expected to produce toxicological effects.

## Regulatory Status

3-mercaptohexanol is not on the FDA's Generally Recognized As Safe (GRAS) list. However, this does not indicate the substance is unsafe; rather, it reflects that a formal GRAS determination petition has not been submitted or completed through the FDA review process. Many flavor compounds used in food operate under different regulatory frameworks.

The compound is regulated as a flavor ingredient and may be used under FDA regulations for food additives (21 CFR Part 172) where applicable. Its use in the European Union is governed by the EU Flavouring Regulation (EC) 1334/2008, which establishes safety standards for flavoring substances.

The absence of a specific GRAS status does not preclude its use in foods, as manufacturers may petition for GRAS recognition or use the compound under established flavor additive regulations when appropriate safety documentation is provided.

## Key Studies

Published peer-reviewed literature specifically evaluating 3-mercaptohexanol toxicology is limited. However, the compound has been studied as a natural flavor component in viticulture and food science research examining its role in wine aroma and sensory quality. Research in the flavor chemistry field indicates that thiol-containing compounds similar to 3-mercaptohexanol do not demonstrate mutagenic or carcinogenic potential in standard screening models.

The International Organization of the Flavor Industry (IOFI) maintains databases of flavor ingredient safety information, and many thiol compounds used in flavoring have undergone comprehensive safety assessment. Industry safety data, combined with the absence of reported adverse effects over decades of use, supports the reasonable safety of this ingredient at typical 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. "3-mercaptohexanol — Safety, regulation, and evidence." https://additivefacts.com/additives/3-mercaptohexanol. Accessed 2026-05-19.