Flavor ingredient regulatory record
3-(Methylthio)propyl isothiocyanate
3-(Methylthio)propyl isothiocyanate is an isothiocyanate in the sulfur family, FEMA GRAS under FEMA number 3312 (CAS 505-79-3). Its odor is pungent, mustard-like, sulfurous, earthy.
- FEMA
- 3312
- CAS
- 505-79-3
- JECFA
- 1564
- EU FL
- 12.030
- Formula
- C5H9NS2
GRAS status: FEMA GRAS, publication 5. Recorded by FDA in the Substances Added to Food inventory under CAS 505-79-3.
Structure
Identity
Also known as: Propane, 1-isothiocyanato-3-(methylthio)-, Isothiocyanic acid, 3-(methylthio)propyl ester, 1-Isothiocyanato-3-(methylthio)propane, 3-Methylthiopropyl isothiocyanate, Iberverin, 3-Methylsulfanylpropylisothiocyanate, 1-Isothiocyanato-3-(methylsulfanyl)propane, 1-Isothiocyanato-3-methylsulfanylpropane, iberverin, 3-methylthiopropyl isothiocyanate, propane, 1-isothiocyanato-3-(methylthio)-, isothiocyanic acid, 3-(methylthio)propyl ester.
Can 3-(Methylthio)propyl isothiocyanate be labeled natural?
3-(Methylthio)propyl isothiocyanate occurs in nature, so the label depends on the route: 3-(Methylthio)propyl isothiocyanate won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized 3-(Methylthio)propyl isothiocyanate is artificial. The EU and UK grant the natural claim only to that natural route; Mercosur and Mexico call synthetic material identical-to-natural.
- United States
- Natural or artificial, by process
- European Union and UK
- Natural only from natural material
- Mercosur and Mexico
- Natural or identical-to-natural
How each market defines the classes: natural vs artificial flavor under 21 CFR 101.22.
Regulatory status, with citations
United States
3-(Methylthio)propyl isothiocyanate is FEMA GRAS under FEMA number 3312. 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 12.030, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.
JECFA (WHO / FAO)
JECFA number 1564, evaluated at the 65th meeting in 2005. No safety concern at current levels of intake when used as a flavouring agent.
Other US flags
Not on the California Proposition 65 list.
TSCA Inventory status
A flavor ingredient is also an industrial chemical. 3-(Methylthio)propyl isothiocyanate appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 505-79-3, where EPA names it Propane, 1-isothiocyanato-3-(methylthio)-.
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: Pungent, mustard-like, sulfurous, earthy.
Where it is used
3-(Methylthio)propyl isothiocyanate is used in seasoning, condiments, savory dishes and snacks, typically as a sulfur note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to 3-(Methylthio)propyl isothiocyanate by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| Amyl isothiocyanate | 4417 | 95% | In nature |
| 4-Pentenyl isothiocyanate | 4427 | 94% | In nature |
| Hexyl isothiocyanate | 4422 | 90% | In nature |
| Phenethyl isothiocyanate | 4014 | 89% | In nature |
| 5-Hexenyl isothiocyanate | 4421 | 85% | In nature |
More isothiocyanates in this index
Isopropyl isothiocyanate · 2-Butyl isothiocyanate · Isoamyl isothiocyanate · Methyl isothiocyanate · 5-(Methylthio)pentyl isothiocyanate · Hexyl isothiocyanate
3-(Methylthio)propyl isothiocyanate FAQ
Is 3-(Methylthio)propyl isothiocyanate FEMA GRAS?
Yes. The FEMA Expert Panel lists 3-(Methylthio)propyl isothiocyanate as GRAS under FEMA number 3312. It is also codified at 21 CFR 172.515.
What are the FEMA and CAS numbers for 3-(Methylthio)propyl isothiocyanate?
3-(Methylthio)propyl isothiocyanate is FEMA 3312, CAS 505-79-3. FEMA files it in the sulfur flavor category.
Does 3-(Methylthio)propyl isothiocyanate count as natural in the US and the EU?
Since 3-(Methylthio)propyl isothiocyanate is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when 3-(Methylthio)propyl isothiocyanate is synthesized. The EU and UK grant the natural claim only to that natural route; Mercosur and Mexico call synthetic material identical-to-natural.
Is 3-(Methylthio)propyl isothiocyanate on the EU Union List?
3-(Methylthio)propyl isothiocyanate is on the EU Union List of flavouring substances as FL 12.030 (Annex I Part A) under Regulation 1334/2008.
Has JECFA evaluated 3-(Methylthio)propyl isothiocyanate?
Yes. JECFA number 1564, evaluated at the 65th meeting in 2005. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.
How is 3-(Methylthio)propyl isothiocyanate described, and where does it show up?
Flavorists describe 3-(Methylthio)propyl isothiocyanate as pungent, mustard-like, sulfurous, earthy. It is used in seasoning, condiments, savory dishes and snacks.
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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 3-METHYLTHIOPROPYL ISOTHIOCYANATE under CAS 505-79-3 and carries its FEMA number, its JECFA flavor number. The inventory is searchable at FDA. FDA records its technical effect as 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.