trans-Limonene oxide is a limonene-derived monoterpene epoxide that appears as a minor oxidation or biotransformation product in citrus and other volatile systems. The strongest evidence located for this AromaForge record supports identity, fragrance-flavor context, and limited ecological or safety signals rather than any consumer-facing wellness effect. For archive use, it is most accurate to describe trans-limonene oxide as a citrus epoxide marker with sensitization relevance and modest preclinical context.
Chemical identity and composition
NIST resolves trans-limonene oxide as C10H16O with CAS 4959-35-7, while PubChem's stereospecific trans record maps to CID 449290. In the archive, Tangerine lists trans-limonene oxide at 0.553%, but that oil file currently uses a different CAS value; this constituent file follows the live NIST and PubChem identity instead of the local mismatch.
Aroma and practical use
- Use the recorded citrus, fresh, minty, herbaceous descriptors to explore a blend's scent character; perceived strength also depends on the other ingredients.
- Review the flagged use concerns across every contributing oil and the selected dilution.
- 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.
oxidized limonene sensitization
A 1992 Contact Dermatitis study reported that a mixture of cis and trans isomers of (+)-limonene oxide was a potent sensitizer in animal testing, supporting limonene oxide as part of oxidized limonene's allergen profile.
Measured: allergenic potential of oxidation products
The source assessment applies to its specified exposure and preparation; this entry is not an unrestricted-use clearance.
mosquito repellency field signal
A 2016 Malaria Journal study identified trans-limonene oxide as one of the chicken-specific non-host volatiles that significantly reduced mosquito trap catches in house-field testing.
Measured: reduction in trap catches
This experimental finding does not establish benefit, dose or safety in people using this blend.
Use concerns and concentration limits
Sensitization concernFlagged
Flagged in the constituent reference; assess the source, route and finished-product concentration.
Phototoxicity concernNot flagged
Not flagged in the current model. This is not proof of absence or unrestricted safety.
Oxidation concernFlagged
Flagged in the constituent reference; assess the source, route and finished-product concentration.
Penetration enhancementNot flagged
Not flagged in the current model. This is not proof of absence or unrestricted safety.
Screening assumption (family fallback). It is not a verified constituent-specific exposure limit.
model fallback · Ascaridole (monoterpene endoperoxide) sensitization and reactivity literatureThe strongest directly relevant safety signal in this pass is sensitization context tied to oxidized limonene products that include limonene oxide isomers.
The source assessment applies to its specified exposure and preparation; this entry is not an unrestricted-use clearance.
The Good Scents entry reviewed in this pass flags sensitization as the IFRA critical effect and shows 'not for fragrance use' and 'not for flavor use' on that page; this should be treated as industry-reference context rather than a stand-alone regulatory determination.
This reference does not establish a therapeutic result or a safe use level for a custom oil blend.
No constituent-specific human clinical safety study for isolated trans-limonene oxide was verified in this pass.
This reference does not establish a therapeutic result or a safe use level for a custom oil blend.
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
oxidative limonene epoxidation product
The available safety literature treats limonene oxide as one of the oxidation products formed when limonene is exposed to air, linking the constituent to the sensitization profile of oxidized limonene mixtures.
The source assessment applies to its specified exposure and preparation; this entry is not an unrestricted-use clearance.
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 (6)
- Direct isolated pharmacology for trans-limonene oxide was sparse in the reviewed public literature.
- The main safety study identified a cis/trans mixture rather than the isolated trans isomer, so the sensitization signal is relevant but not perfectly isomer-specific.
- No constituent-specific dermal-limit monograph or human tolerability dataset was verified in this pass.
- Second pass (2026-07-13): a RIFM fragrance ingredient safety assessment PDF exists for the related limonene-oxide isomer 'menthene-1,2-epoxide' (CAS 1195-92-2, https://fragrancematerialsafetyresource.elsevier.com/sites/default/files/1195-92-2.pdf) but failed to load on two fetch attempts, and in any case covers a different CAS than this trans isomer (4959-35-7). Search snippets indicate the 2015 IFRA Volume of Use Survey cleared limonene oxide isomers at screening level ('not applicable' status) without establishing a numeric dermal restriction. The prior 0.1% dermal_limit_pct had no traceable citation in this record and is corrected to null pending real data.
- No constituent-specific numeric dermal reference is available here.
- Some findings do not record an explicit exposure route; consult the linked study before applying them to a use.