Flavor ingredient regulatory record
Ammonium hydrogen sulphide
Ammonium hydrogen sulphide is a thiol in the sulfur family, FEMA GRAS under FEMA number 2053 (CAS 12124-99-1). Its odor is rotten, egg-like, pungent, sulfurous.
- FEMA
- 2053
- CAS
- 12124-99-1
- EU FL
- 16.059
- EC
- 235-184-3
GRAS status: FEMA GRAS, publication 3. Recorded by FDA in the Substances Added to Food inventory under CAS 12135-76-1.
Structure
Under review
The structure for Ammonium hydrogen sulphide is still under identity review, so no drawing is shown until the record is confirmed.
Identity
Also known as: Ammonium sulfide ((NH4)(SH)), Ammonium sulfide ((NH4)(HS)), Ammonium bisulfide, Ammonium hydrogen sulfide, Ammonium hydrosulfide, Ammonium sulfhydrate, Monoammonium sulfide, Ammonium mercaptan, Ammonium hydrogen sulfide (NH4HS), ammonium bisulfide, ammonium hydrosulfide, ammonium sulfhydrate.
Can Ammonium hydrogen sulphide be labeled natural?
Nature occurrence: Not yet found in nature (provisional).
Nature occurrence has not been settled for this substance, so the natural or artificial class is not stated here. The FEMA GRAS status does not depend on it.
Regulatory status, with citations
United States
Ammonium hydrogen sulphide is FEMA GRAS under FEMA number 2053. 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 16.059, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.
JECFA (WHO / FAO)
Ammonium hydrogen sulphide has not been evaluated by JECFA as a flavouring agent, or no evaluation is on file.
Other US flags
Not on the California Proposition 65 list.
TSCA Inventory status
A flavor ingredient is also an industrial chemical. Ammonium hydrogen sulphide appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 12124-99-1, where EPA names it Ammonium sulfide ((NH4)(SH)).
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: Rotten, egg-like, pungent, sulfurous.
Taste: Bitter, metallic, unpleasant.
Where it is used
Ammonium hydrogen sulphide is used in flavoring agent, food preservation and aroma enhancer, typically as a sulfur note.
Ammonium hydrogen sulphide FAQ
Does ammonium hydrogen sulphide have FEMA GRAS status?
Ammonium hydrogen sulphide holds FEMA GRAS status under FEMA number 2053. The Code of Federal Regulations lists it at 21 CFR 172.515.
How do I cite ammonium hydrogen sulphide by FEMA or CAS number?
Cite ammonium hydrogen sulphide as FEMA 2053 or CAS 12124-99-1; both point to the same entry. Its flavor category is sulfur.
What does ammonium hydrogen sulphide smell and taste like, and where is it used?
The odor of ammonium hydrogen sulphide is rotten, egg-like, pungent, sulfurous. On the palate it is bitter, metallic, unpleasant. Typical uses are flavoring agent, food preservation and aroma enhancer.
Can ammonium hydrogen sulphide be used in the EU and UK?
Yes. FL 16.059 is the Union List entry for ammonium hydrogen sulphide, annex I Part A, under Regulation 1334/2008, and the UK keeps the same list.
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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 AMMONIUM SULFIDE under CAS 12135-76-1 and carries its FEMA number and its 21 CFR citations. The inventory is searchable at FDA. FDA records its technical effect as antioxidant, flavor enhancer, 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.