2-Nonanone is an aliphatic ketone found in some essential-oil and plant volatile profiles, including rue chemotypes in this archive. Its scent is typically described as fatty, green, herbal, and slightly cheesy. Current source support is strongest for identity, aroma, and non-clinical bioactivity such as antifungal and plant-signaling effects; human aromatherapy-style evidence remains sparse.
Aroma and practical use
- Use the recorded fatty, green, herbal, cheesy, herbaceous descriptors to explore a blend's scent character; perceived strength also depends on the other ingredients.
- Read the route, preparation and experimental context before using a study finding to choose an oil.
Reported benefits and effects
Findings retain their study context. An animal or laboratory result describes that experiment.
A recent antifungal study reported that 2-nonanone inhibited spore germination and damaged mycelium in Pseudogymnoascus destructans, with measurable minimum inhibitory activity.
A recent antifungal study reported that 2-nonanone inhibited spore germination and damaged mycelium in Pseudogymnoascus destructans, with measurable minimum inhibitory activity.
This experimental finding does not establish benefit, dose or safety in people using this blend.
A tomato-rhizosphere study reported that bacterial volatile 2-nonanone could trigger innate immunity-related responses even below the GC-MS detection limit used in that system.
A tomato-rhizosphere study reported that bacterial volatile 2-nonanone could trigger innate immunity-related responses even below the GC-MS detection limit used in that system.
This experimental finding does not establish benefit, dose or safety in people using this blend.
Use concerns and concentration limits
Sensitization concernNot flagged
Not flagged in the current model. This is not proof of absence or unrestricted safety.
Phototoxicity concernNot flagged
Not flagged in the current model. This is not proof of absence or unrestricted safety.
Oxidation concernNot flagged
Not flagged in the current model. This is not proof of absence or unrestricted safety.
Penetration enhancementNot flagged
Not flagged in the current model. This is not proof of absence or unrestricted safety.
A recorded constituent reference, not a recommended oil dilution. Product category, source applicability and all contributing oils must be checked before use.
recorded reference · RIFM fragrance ingredient safety assessment, 2-nonanone, CAS 821-55-6 (Food Chem Toxicol 149:111934, 2021, full text via https://fragrancematerialsafetyresource.elsevier.com/sites/default/files/821-55-6.pdf), Table 1: maximum acceptable concentration for IFRA Category 5 (products applied to face/body by hand, primarily leave-on) is 0.10% based on the non-reactive Dermal Sensitization Threshold; human maximization test showed no sensitization reactions at 5%.Screening assumption (verified). It is not a verified constituent-specific exposure limit.
model fallback · RIFM fragrance ingredient safety assessment, 2-nonanone, CAS 821-55-6 (Food Chem Toxicol 149:111934, 2021, full text via https://fragrancematerialsafetyresource.elsevier.com/sites/default/files/821-55-6.pdf), Table 1: maximum acceptable concentration for IFRA Category 5 (products applied to face/body by hand, primarily leave-on) is 0.10% based on the non-reactive Dermal Sensitization Threshold; human maximization test showed no sensitization reactions at 5%.Public SDS-style records consistently frame neat 2-nonanone as an eye and skin irritant, and some also flag harmful-if-swallowed or aquatic-hazard language.
This reference does not establish a therapeutic result or a safe use level for a custom oil blend.
No leave-on dermal maximum specific to aromatherapy use was verified in this pass.
This reference does not establish a therapeutic result or a safe use level for a custom oil blend.
No direct public citation is attached to this entry.
Constituents it may interact with
No constituent-pair interaction is recorded for this identity. The report does not assume either amplification or incompatibility.
How the effects were investigated
Volatile-mediated antifungal action with damage to fungal growth structures and suppression of spore germination.
Volatile-mediated antifungal action with damage to fungal growth structures and suppression of spore germination.
This experimental finding does not establish benefit, dose or safety in people using this blend.
Volatile signaling that can elicit innate immunity in the tomato rhizosphere at very low exposure levels.
Volatile signaling that can elicit innate immunity in the tomato rhizosphere at very low exposure levels.
This experimental finding does not establish benefit, dose or safety in people using this blend.
What this report cannot establish
- A reported constituent percentage does not establish an effective human therapeutic dose or the amount absorbed into the body.
- The presence of a constituent does not guarantee a clinical benefit, rash treatment or sleep improvement from a custom blend.
- An unflagged concern or missing use limit does not establish safety for ingestion, inhalation, skin exposure or a particular person.
- A candidate constituent interaction does not establish that two oils amplify one another at the selected proportions.
- Constituent descriptors alone do not establish a precise top, heart or base lifetime in a finished blend.
Known data gaps (3)
- No human clinical or aromatherapy-specific studies for isolated 2-nonanone were verified in this pass.
- Second pass (2026-07-13): located the full-text RIFM (2021) fragrance safety assessment PDF for CAS 821-55-6, which resolved the dermal ceiling gap (IFRA Category 5 leave-on limit 0.10%, DST-based).
- Some findings do not record an explicit exposure route; consult the linked study before applying them to a use.