Material guide · 8
Material guide: citronellol — the waxy rose structure often richer than geraniol
· 12 min read
Measured rose oils contain roughly 20.35–44.75% citronellol, overall more than geraniol. It supplies waxy thickness and soft sweetness, the second part of the rose trio.
The geraniol guide called geraniol the sweet, bright half of the rose. This piece covers the other half: waxy, leathery, the underside of the petal.
What matters
- In measured rose oils, citronellol's share (20.35–44.75%) runs higher overall than geraniol's, approaching half in the richest genotype. The rose trio: citronellol + geraniol + phenethyl alcohol.
- It closes the oxidation trilogy. In tested dermatitis patients, purified citronellol gave 0.15–0.31% positive reactions and oxidised citronellol 0.61–4.5%, several-fold to more than tenfold higher. Manage it like the first two chapters: sealed, dark, dated.
- 119 suppliers, cheap. Add it to the same order as the rest of the trio and you're done.
The record
| CAS | 26489-01-0 |
| Formula | C₁₀H₂₀O |
| MW | 156.27 |
| Odour | floral, leathery, waxy, rose, citrus, sweet, green, fatty, terpenic |
| Strength | medium |
| Substantivity | 56 h (neat, on a strip) |
| Specific gravity | 0.850–0.860 (25 °C) |
| Shelf life | 24 months or longer (cool, dark, sealed) |
| Registers | GRAS, JECFA, CoE, FEMA GRAS, IFRA |
Plain reading: CAS is the material's ID number. Against geraniol (C₁₀H₁₈O), the formula carries two extra hydrogens; citronellol is simply geraniol with one double bond removed, which is why its character sits lower and waxier. At 56 hours its substantivity matches geraniol's 60. Both are late-heart materials.
How much of the rose is it?
The geraniol guide quoted Kumar and colleagues' 2023 profiling of six damask rose genotypes. Here is the same finding with the protagonist swapped:
Acyclic monoterpene alcohols citronellol (20.35–44.75%) and geraniol (15.63–27.76%) were highest.
Across these six genotypes, citronellol reached the highest measured values of any aroma constituent (up to 44.75%), its range running above geraniol's overall. In the richest genotype that means nearly one drop in two. When you wonder where the rose gets that waxy, petal-thick texture, the answer is mostly citronellol.
The trio's division of labour once more: geraniol for sweetness and brightness, citronellol for wax and body, phenethyl alcohol for dried petal and honey. Start at 5:3:2 (the geraniol guide's starter experiment) and push the citronellol up when you want a riper rose.
Oxidation changes it after opening
In dermatitis-patient tests, oxidised citronellol produced higher positive rates than purified material. The full comparison with linalool, geraniol and linalyl acetate is in An opened bottle is no longer the same material; this guide returns to citronellol’s share of a rose.
Smelling it
Our record gives it 9 descriptors: floral, leathery, waxy, rose, citrus, sweet, green, fatty, terpenic.
- Evaluate at 10%. Neat it turns fatty and stuffy.
- "Leathery" is where it parts company with geraniol. Smell them side by side once: geraniol is the rose's smell, citronellol is the rose's texture.
- Watch the sound-alike neighbours. Citronellal (70 suppliers) is a different molecule, sharper and lemonier, a regular in insect repellents; citronella oil (54) is a whole-plant essential oil, not the molecule. I nearly ordered the aldehyde myself the first time round, so check the ending of the word before you pay.
The catalogue family
| Item | What it is |
|---|---|
| citronellol (119 suppliers) | the material itself — the rose's waxy half |
| citronellyl acetate (77) | the acetate — lighter, fruitier; a standard rose-accord modifier |
| citronellal (70) | sounds alike, is not it: an aldehyde, sharp and lemony |
| citronella oil (54) | also not it: the distilled whole-plant oil |
| rhodinol (41) | "rose alcohol" — traditionally a citronellol/geraniol-rich fraction; a grade name, not a single molecule |
Regulatory
Listed on GRAS, JECFA, CoE, FEMA GRAS, IFRA. As always, registers carry no limit values. Citronellol is a component of fragrance mix II (Hagvall's words), so for skin formulae consult the current IFRA Standards and manage freshness together with the rest of this family.
Buying it
- Order the rose trio in one shipment: citronellol, geraniol, phenethyl alcohol.
- Read the label twice. Citronellol, citronellal and citronella oil are three different things.
- Freshness follows the trilogy's rules: small bottles, recent batches, dated openings.
→ Citronellol in the database: full properties, supplier list, suggested pairings. → Geraniol | Phenethyl alcohol | Citronellal | Search by odour: try "rose waxy" for its neighbours.
References
L. Hagvall, J. Rudbäck, J. Bråred Christensson & A.-T. Karlberg, Patch testing with purified and oxidized citronellol, Contact Dermatitis, 83(5), 372–379 (2020). PMID 32638395
A. Kumar et al., Phenotyping floral traits and essential oil profiling revealed considerable variations in clonal selections of damask rose (Rosa damascena Mill.), Scientific Reports, 13, 8101 (2023). PMID 37208367