# Thioacetic Acid

> Source URL: https://additivefacts.com/additives/thioacetic-acid
> Markdown URL: https://additivefacts.com/additives/thioacetic-acid.md

**Safety rating:** SAFE
**CAS number:** 507-09-5
**Category:** flavoring
**FDA GRAS:** no
**Adverse events (FDA AERS):** 0
**FDA recalls:** 0
**Last updated:** 2026-04-04

## Summary

Thioacetic acid (CAS 507-09-5) is an organic compound used as a flavoring agent in food products. It contributes sulfur-based aromatic notes and is employed in small quantities to enhance flavor profiles in various food applications.

## 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 Thioacetic Acid?

Thioacetic acid is a simple organic compound consisting of an acetyl group bonded to a thiol functional group. Its chemical structure (CH3COSH) makes it one of the smallest sulfur-containing flavor compounds used in the food industry. The compound is a colorless to pale yellow liquid with a characteristic sharp, sulfurous odor typical of thiol-containing molecules. It exists as a volatile compound that readily evaporates, making it useful for creating aromatic notes in food flavoring applications.

## Common Uses

Thioacetic acid is primarily used as a flavoring agent or flavoring adjuvant in food manufacturing. It functions to provide or enhance sulfur-based aromatic characteristics in various food products, particularly in savory applications where meaty, cooked, or roasted notes are desired. The compound may be incorporated into flavor blends, seasonings, soups, sauces, and processed meat products at very low concentrations. Its use is subject to flavor industry standards and established safe use levels based on its volatile nature and sensory properties.

## Safety Assessment

As of available FDA records, thioacetic acid has generated zero adverse events and zero recall incidents. This suggests a favorable safety profile in actual use within food manufacturing. The compound's safety in food applications is supported by its limited exposure levels—it is used in small quantities as a flavoring agent where only trace amounts contribute to the final product's sensory characteristics. The volatility of thioacetic acid means that exposure potential decreases further as the product is prepared and consumed. General toxicological data on thioacetic acid indicates low systemic toxicity at exposure levels relevant to food use, though comprehensive public safety dossiers specific to food applications may be limited in the scientific literature.

## Regulatory Status

Thioacetic acid does not currently hold FDA GRAS (Generally Recognized as Safe) status. However, it may be used in food products under FDA regulations permitting the use of flavoring substances that have not been formally affirmed as GRAS, provided they meet safety standards and are used in accordance with established flavoring industry practices and limitations. The compound is not listed as a banned substance in major regulatory jurisdictions. Its non-GRAS status does not necessarily indicate safety concerns; rather, it reflects that the specific safety petition or self-affirmation process for GRAS determination has not been formally completed or submitted for this particular ingredient. Manufacturers using thioacetic acid must ensure compliance with FDA regulations for flavoring substances and maintain appropriate documentation of safe 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. "Thioacetic Acid — Safety, regulation, and evidence." https://additivefacts.com/additives/thioacetic-acid. Accessed 2026-05-20.