Flavor ingredient regulatory record
(+/-)-2-Mercaptomethylpentan-1-ol
(+/-)-2-Mercaptomethylpentan-1-ol is a thiol in the sulfur family, FEMA GRAS under FEMA number 3995 (CAS 258823-39-1). Its odor is sulfurous, pungent, onion, garlic.
- FEMA
- 3995
- CAS
- 258823-39-1
- JECFA
- 1290
- EU FL
- 12.241
- Formula
- C6H14OS
- EC
- 434-920-2
GRAS status: FEMA GRAS, publication 20. Recorded by FDA in the Substances Added to Food inventory under CAS 258823-39-1.
Structure
Identity
Also known as: 1-Pentanol, 2-mercapto-2-methyl-, 2-Mercapto-2-methyl-1-pentanol, 2-Mercapto-2-methylpentan-1-ol, 2-Methyl-2-sulfanylpentan-1-ol, 2-mercapto-2-methylpentan-1-ol, 2-mercapto-2-methyl-1-pentanol, 2-methyl-2-sulfanylpentan-1-ol, 1-pentanol, 2-mercapto-2-methyl-, (+-)2-mercapto-2-methylpentan-1-ol, 2-mercapto-2-methylpentan-1-ol, (+-)-, (+-)2-mercapto-2-methylpentan-1-ol [fhfi], 1-pentanol,2-mercapto-2-methyl-.
Can (+/-)-2-Mercaptomethylpentan-1-ol 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
(+/-)-2-Mercaptomethylpentan-1-ol is FEMA GRAS under FEMA number 3995. 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 12.241, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.
Other US flags
Not on the California Proposition 65 list. Listed on the EPA TSCA inventory.
TSCA Inventory status
A flavor ingredient is also an industrial chemical. (+/-)-2-Mercaptomethylpentan-1-ol appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 258823-39-1, where EPA names it 1-Pentanol, 2-mercapto-2-methyl-.
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 regulatory flags
| Flag | EPA definition | What it obliges |
|---|---|---|
| PMN | Indicates a commenced PMN substance. | Nothing new. The substance already went through premanufacture review and someone filed a notice of commencement, which is why it is on the Inventory. It is an existing chemical and needs no new premanufacture notice. Read more |
PMN does not establish: The flag records how the substance arrived, not what may be done with it. Check the flags beside it.
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: Sulfurous, pungent, onion, garlic.
Where it is used
(+/-)-2-Mercaptomethylpentan-1-ol is used in savory dishes, seasoning blends, sauces and meat products, typically as a sulfur note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to (+/-)-2-Mercaptomethylpentan-1-ol by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| 4-Mercapto-4-methyl-2-hexanone | 4583 | 90% | Not determined |
| Ethyl 2-Mercapto-2-methylpropionate | 4714 | 68% | Not determined |
More thiols in this index
2,3 or 10-Mercaptopinane · 3-Mercapto-2-pentanone · 3,4-Dimethylthiophene · Diisoamyl disulfide · 3-Mercaptohexanol · Dimethyl trisulfide
(+/-)-2-Mercaptomethylpentan-1-ol FAQ
Is (+/-)-2-Mercaptomethylpentan-1-ol on the FEMA GRAS list?
It is. FEMA number 3995 covers (+/-)-2-Mercaptomethylpentan-1-ol. The Code of Federal Regulations lists it at 21 CFR 172.515.
What is the FEMA number for (+/-)-2-Mercaptomethylpentan-1-ol?
The FEMA number for (+/-)-2-Mercaptomethylpentan-1-ol is 3995 and its CAS registry number is 258823-39-1. Its flavor category is sulfur.
What is (+/-)-2-Mercaptomethylpentan-1-ol used for?
(+/-)-2-Mercaptomethylpentan-1-ol is described as sulfurous, pungent, onion, garlic. It shows up in savory dishes, seasoning blends, sauces and meat products.
What did JECFA conclude about (+/-)-2-Mercaptomethylpentan-1-ol?
JECFA evaluated (+/-)-2-Mercaptomethylpentan-1-ol under JECFA number 1290. The panel concluded: no safety concern at current levels of intake.
Is (+/-)-2-Mercaptomethylpentan-1-ol approved in the EU?
Yes. FL 12.241 is the Union List entry for (+/-)-2-Mercaptomethylpentan-1-ol, 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 2-MERCAPTO-2-METHYL-1-PENTANOL under CAS 258823-39-1 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.