Compounds · Other compounds · Microbial origin
2,4,6-Trichloroanisole
Also known as TCA · 2,4,6-TCA — an analysis may use any of these names
Mould, damp rag, old paper. This is the smell of corked wine.
- CAS
- 87-40-1
- Formula
- C7H5Cl3O
- Molar mass
- 211.47
- Odour threshold
- 0.030 pptin water
- Boiling point
- ≈ 241 °C estimated
The two axes are 65 points apart. Volatility tells you whether the compound leaves a surface early or late; the threshold tells you how much of it the nose needs before it notices. When the two sit this far apart, they explain things the percentages on an analysis cannot explain on their own.
Where it comes from
Biosynthetic pathway: Microbial origin — made by bacteria and yeasts, not by plants.
Trichloroanisole is made by fungi, but its raw material is not. The fungi attach a methyl group to chlorine compounds — and the chlorine in wood and corks usually comes from bleaches or preservatives used by people. It is a smell that exists only because two sources meet.
About the threshold figure
One of the lowest thresholds ever measured in humans. A few parts per trillion are enough to ruin a whole bottle of wine.
Published thresholds differ by several orders of magnitude, because of differences in measuring method, sample purity and panel. The figure here is an order of magnitude for relative comparison, not a measurement. We give it only for compounds where the literature broadly agrees — 52 of the 106 compounds in the library. The rest are left blank rather than guessed.
Why it sits where it does
An aromatic ring carrying three chlorine atoms, very heavy and stable. The human nose’s detection threshold for this compound is among the lowest ever measured.
Where else you meet it
Tainted wine corks, damp storerooms, wood treated with anti-mould agents.
Dictionary entries that mention this compound
About the boiling-point figure
Not yet cross-checked against a primary source. The value is provisional, used to place the compound on the volatility axis. Why this detail matters