Heneicosane is a straight-chain C21 alkane that appears in the AromaForge archive mainly as a waxy hydrocarbon supporting rose-otto profiles rather than as an odor-active centerpiece. The strongest live evidence supports its identity, its repeated occurrence in rose and related floral materials, and a measurable semiochemical role in Aedes mosquito oviposition studies. Safety coverage is better than efficacy coverage because public sources include both older mammalian toxicity work and a 2026 RIFM fragrance-safety citation, while constituent-specific human-benefit literature remains sparse.
Chemical identity and composition
NIST lists heneicosane as C21H44 with CAS 629-94-7 and common names n-heneicosane, n-henicosane, and henicosane. In perfumery and essential-oil context it behaves as a long-chain saturated hydrocarbon contributing waxy stearoptene character, especially in rose otto fractions where it supports body more than overt odor impact.
Aroma and practical use
- Use the recorded waxy, faint, oily, paraffinic 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 2009 PubMed abstract reported that female Aedes aegypti showed dose-dependent antennal responses to n-heneicosane, with attraction in Y-maze assays at lower doses and the highest egg deposition at 10 ppm, while a higher dose became repellent.
This is the most specific functional literature found for isolated heneicosane and it is firmly in insect semiochemistry, not human-use evidence.
This experimental finding does not establish benefit, dose or safety in people using this blend.
A 2013 PubMed abstract on prenatal developmental toxicity in Wistar rats reported that n-heneicosane at 1 g/kg did not induce embryotoxicity or teratogenicity under the study conditions described in the abstract snippet.
This supports a conservative statement that the mammalian toxicity signal in this specific prenatal model was low at the tested dose.
The source assessment applies to its specified exposure and preparation; this entry is not an unrestricted-use clearance.
A 2018 PubMed abstract snippet reported low acute inhalation toxicity for n-heneicosane and for its combination with diflubenzuron in the tested mammalian model.
The available access is only a snippet, so the archive should avoid overstating beyond the study's low-toxicity conclusion.
The source assessment applies to its specified exposure and preparation; this entry is not an unrestricted-use clearance.
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.
No numeric constituent-specific use limit is available here. Missing is not an unrestricted-use clearance.
PubChem snippets summarize older animal work reporting LD50 values above 5 g/kg by intraperitoneal and dermal routes and no significant primary skin irritation in the cited tests.
The source assessment applies to its specified exposure and preparation; this entry is not an unrestricted-use clearance.
No direct public citation is attached to this entry.
A 2026 PubMed citation indicates that a dedicated RIFM fragrance ingredient safety assessment for heneicosane now exists, strengthening fragrance-safety coverage compared with many niche hydrocarbons.
The source assessment applies to its specified exposure and preparation; this entry is not an unrestricted-use clearance.
No direct public citation is attached to this entry.
Despite that safety coverage, constituent-specific human efficacy or wellness evidence for isolated heneicosane was not 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
concentration_dependent_olfactory_attraction_and_repellency_in_mosquitoes
The Aedes paper supports heneicosane functioning as an oviposition cue with attraction at lower doses and repellency at higher doses.
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 (7)
- No human clinical literature specific to isolated heneicosane was verified in this pass.
- Most direct functional evidence located here is insect semiochemical or toxicology work rather than fragrance-use or wellness research.
- The full text of the 2026 RIFM heneicosane assessment was not directly read in this pass, so safety conclusions are kept high-level.
- 2026-07-13 verification pass: repeated attempts to fetch the full-text RIFM assessment (PubMed record 42106103) and researchgate/elsevier mirrors timed out or returned no readable content; no explicit numeric dermal limit could be confirmed, so the prior dermal_limit_pct (0.1) placeholder has been corrected to null pending full-text access.
- 2026-07-13 second-pass verification: fetched The Good Scents Company listing for henicosane (CAS 629-94-7) directly (different source from the RIFM/PubMed angle already tried). Its Safety Information section lists Dermal and Inhalation Toxicity as 'Not determined,' and its Safety in Use Information section only gives a flavor-usage recommendation ('not for flavor use') with no fragrance usage level listed. This corroborates the absence of a public numeric dermal limit; dermal_limit_pct, sensitizing, and penetration_enhancer remain unverified. Also re-attempted a direct CAS search ('629-94-7' RIFM NESIL) which surfaced only supplier/SDS pages, not the RIFM assessment text.
- 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.