Compounds · Sesquiterpenes · Terpenoid pathway
β-Caryophyllene
Also known as (−)-trans-Caryophyllene · Caryophyllene — an analysis may use any of these names
Wood, pepper, dry. It stays a very long time, and almost nobody notices its presence until it is gone.
- CAS
- 87-44-5
- Formula
- C15H24
- Molar mass
- 204.36
- Odour threshold
- 64 ppbin water
- Boiling point
- ≈ 264 °C at atmospheric pressure
For this compound the two axes sit close together. Volatility tells you whether it leaves a surface early or late; the threshold tells you how much of it the nose needs before it notices.
Must be declared on the label
This compound was added by Regulation (EU) 2023/1545 to the list of allergens that must be declared individually on cosmetic labels in the European Union. Name to use on the label: BETA-CARYOPHYLLENE.
The declaration threshold is 0.001% in leave-on products and 0.01% in rinse-off products. This is an EU requirement — see the regulations page for why it matters beyond the EU. This is not legal advice.
Where it comes from
Biosynthetic pathway: Terpenoid pathway — plants build them from identical five-carbon blocks.
About the threshold figure
Moderate. Lower than most monoterpenes, which is one reason sesquiterpenes can still be smelled even though they evaporate slowly.
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
A fifteen-carbon sesquiterpene, much larger than the monoterpenes, so it boils much higher. That is why it sits near the end of the band in every analysis.
Where else you meet it
Black pepper, clove, hops, and most leaf oils. It is the most common sesquiterpene in the plant kingdom.