8-Mercapto-p-menthan-3-one

In short

8-Mercapto-p-menthan-3-one is a sulfur-containing ketone found in buchu leaf oil. It has an intense blackcurrant and buchu odour and is used in minute traces.

What 8-Mercapto-p-menthan-3-one smells like

8-Mercapto-p-menthan-3-one (thiomenthone, buchu mercaptan) is a potent blackcurrant-type odorant. At 0.001%, ChemicalBook describes it as sweet, pungent, minty and piney, buchu-like, sulphurous and metallic, with blackberry and grapefruit-fruity notes over an earthy background; Moellhausen gives characteristic cassis with herbal, fruity-green, sulphury notes reminiscent of buchu leaf oil; Sigma-Aldrich berry, tropical, minty, fruity and sulphurous.

Leading note: Blackcurrant-buchu
Clear facets: Sulphurous
Supporting facets: Minty, tropical fruit
Faint facets: Metallic
Character: Intense, pungent, juicy, sulphurous

What makes 8-Mercapto-p-menthan-3-one distinctive

The buchu thiol: the catty, sulphurous core of blackcurrant, which becomes juicy and natural only in high dilution.

Concentration and dilution

Extremely potent; described at 0.001%, where the sulphur reads as juicy blackcurrant.

How 8-Mercapto-p-menthan-3-one is used

Used in traces in blackcurrant, tropical and red-fruit accords and flavours.

Typical role: modifier (used in small amounts to change the character of a blend).

How 8-Mercapto-p-menthan-3-one differs from similar materials

Buccoxime: Buccoxime is a fresher, herbal, non-sulphur buchu note; mercaptomenthone is the powerful, sulphurous thiol.
Blackcurrant Bud Absolute: The absolute's catty note comes from trace thiols of this kind; the absolute adds green terpenes and an earthy-woody drydown.

Each difference compares the published descriptions of the two materials. Smell varies with grade, supplier and dilution; compare them side by side on blotters before substituting one for another.

Formulation considerations

Extremely potent and sulfurous; work from 0.01% or weaker and keep it apart from other materials.

Identity and classification

Type: Aroma chemical
Origin: Occurs in nature
Odour family: Fruity / Green
Note position: Top to heart note
Physical form at room temperature: Liquid
Also known as: p-Mentha-8-thiol-3-one
CAS number: 38462-22-5
Molecular formula: C10H18OS
Molecular weight: 186.32 g/mol
IUPAC name: 5-methyl-2-(2-sulfanylpropan-2-yl)cyclohexan-1-one

The CAS number, formula and molecular weight are taken from PubChem compound 61982, whose own record lists this CAS number; checked 19 October 2026.

Safety and compliance

Hazard classification of the neat substance, as PubChem summarises it, read 26 October 2026. Companies notifying the ECHA C&L Inventory classify it (1,550 reports): H317 may cause an allergic skin reaction (94.5% of reports). 40 of the reports find it does not meet the hazard criteria. A skin sensitiser classification concerns handling the neat material and the dose in a finished product; the IFRA Standards, where they apply, set the limits. Unless it is harmonised, this is the notifiers' own classification, not a binding one.

This page is general information, not a safety assessment or a specification. Confirm identity, composition, IFRA status and allergen content from your supplier's documents for the lot you hold.

Materials it works with

Blackcurrant Bud Absolute
Absolute · Fruity / Green — blackcurrant, green, sulphurous, fruity
Buccoxime
Aroma chemical · Fruity / Green — blackcurrant, buchu, green, fruity
Oxane
Aroma chemical · Fruity / Green — tropical, passion fruit, sulphurous, grapefruit
Grapefruit Mercaptan
Aroma chemical · Citrus / Fruity — grapefruit, sulfurous, juicy, tropical

8-Mercapto-p-menthan-3-one is also suggested as a partner on the pages for Buchu Oil, Cassiffix and Prenyl Mercaptan.

Used in formulas and accords

Used in 4 published formulas

8-Mercapto-p-menthan-3-one is an ingredient in 1 perfume formula and 3 accords in the Formula & Accord Library.

Community formulas

Lychee Accord
Community Formula · Accord · listed as “Ribes Mercaptan 1%”, at 1%
Pineapple Accord
Community Formula · Accord · listed as “Ribes Mercaptan”
Tomato Leaf Accord
Community Formula · Accord · listed as “Ribes Mercaptan 1%”, at 1%

RUŌOD House Originals

Original compositions by RUŌOD House.

Blackcurrant Signal
RUŌOD House Original · listed as “8-Mercapto-p-menthan-3-one 0.1% DPG”, at 0.1% in DPG

Questions about 8-Mercapto-p-menthan-3-one

Is 8-Mercapto-p-menthan-3-one natural or synthetic?

The molecule occurs in nature. Commercial 8-Mercapto-p-menthan-3-one may be made by synthesis or obtained from natural sources, so check the supplier's specification if the distinction matters to you.

What is the CAS number of 8-Mercapto-p-menthan-3-one?

38462-22-5. It was checked against PubChem on 19 October 2026.

Which published formulas use 8-Mercapto-p-menthan-3-one?

8-Mercapto-p-menthan-3-one is used in 4 published formulas in the RUŌOD Lab Formula & Accord Library, including Blackcurrant Signal, Lychee Accord and Pineapple Accord. Each is listed with a link under "Used in formulas and accords" on this page.

Sources

PubChem — compound 61982, checked 19 October 2026.
PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 26 October 2026.
ChemicalBook — 8-mercapto-p-menthan-3-one (CAS 38462-22-5) — odour database.
Perflavory (The Good Scents Company) — thiomenthone (with Moellhausen and Pell Wall descriptions) — odour database.
Sigma-Aldrich — 8-mercapto-p-menthan-3-one — manufacturer's description.
Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 20 October 2026. Evidence: more than one published description. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.