Material guide · 38
Material guide: frankincense — a resin burned for millennia, its churchlike endnote pinned down in 2016
· 16 min read
CAS 8016-36-2, the essential oil distilled from Boswellia resin: terpenic, incense, pepper, pine and green. The literature calls it one of the oldest aromatic materials used by humans, yet the molecular source of its signature smell was only found in 2016 — the olibanic acids, present at ppm levels, carrying the old-churchlike endnote. It has broad supply from 93 suppliers; the sister species Indian frankincense and climate-driven habitat contraction are its modern problems.
Stop two of the resin trilogy (stop one was labdanum). Frankincense is the resin that seeps from cut Boswellia trunks and dries into tear-shaped drops, and its smoke has drifted from ancient temples to today's churches. For a material this old, the molecule behind its signature smell only got named in 2016 — like vetiver's 2021, a new answer to an old question.
What matters
- Frankincense oil is a terpenic resin scent: incense, pepper, pine, green — a bright opening over a solemn tail. It has 93 suppliers and 188 hours of longevity (measured neat, a non-conventional value).
- The source of the signature endnote was found in 2016: the olibanic acids, present at ppm levels in every sample tested, carrying the "old churchlike endnote" — another lesson in trace components carrying the signature.
- The flash point is just 35.56 °C, unusually low for this series. Keep it away from flames and hot car interiors; that is practical-knowledge-grade advice.
The basics
| CAS | 8016-36-2 |
| Source | Essential oil distilled from Boswellia resin, natural |
| Odor | terpenic, incense, peppery, spicy, old wood, woody, pine, resinous, green, pungent |
| Odor type | terpenic |
| Strength | medium (database note: evaluate at 10% or less) |
| Longevity | 188 hours (measured neat at 100%, on a blotter) |
| Appearance | colorless to pale yellow clear liquid |
| Flash point | 35.56 °C |
| Shelf life | 24 months or longer (cool, dark, sealed) |
| Listings | GRAS, JECFA, FEMA GRAS, IFRA |
188 hours is a genuine reading rather than the conventional 400 (the vanillin guide explained the convention), and for an essential oil it is very persistent. The 35.56 °C flash point deserves a second look: most materials in this series flash above 90 °C, this one far lower — store and ship it as a flammable.
A five-thousand-year smell, answered in 2016
In 2016, Baldovini's team published the overdue answer in Angewandte Chemie:
Frankincense (olibanum) is one of the oldest aromatic materials used by humans, but the key molecular constituents contributing to its characteristic odor remained unknown. Reported herein is the discovery that (1S,2S)-(+)-trans- and (1S,2R)-(+)-cis-2-octylcyclopropyl-1-carboxylic acids are highly potent and substantive odorants occurring in ppm amounts in all of the frankincense samples analyzed, even those showing radically different volatile compositions. These cyclopropyl-derived acids provide the very characteristic old churchlike endnote of the frankincense odor.
"One of the oldest" is the abstract's own claim; we quote it as written. Two things stand out. First, the ppm amounts: our database files frankincense oil under the terpenic odor type — the bulk is terpenes — but the churchy tail that triggers the memory comes from trace olibanic acids — the trace-carries-the-signature lesson from beta-damascenone and vetiver, replayed in a natural resin. Second, "in all of the samples analyzed": frankincense from different origins varies radically in volatile composition, yet these two acids are the common floor. Our reading: that is the chemical basis of why they all still smell like frankincense.
The modern supply problem
A 2025 model for one frankincense species and region in India projected a roughly 9% overall decline in suitable habitat by 2060. It cannot represent the entire trade, but it is enough reason to record species and origin. The full comparison with sandalwood and tonka is in Natural fragrance materials are not guaranteed.
The family on the catalog
| Entry | What it is |
|---|---|
| frankincense oil (93 suppliers) | The material itself: resin-distilled essential oil with broad supply |
| frankincense resinoid (63 suppliers) | The solvent-extracted resinoid, 284 hours (non-conventional value) |
| boswellia serrata extract (17 suppliers) | Indian frankincense extract: a sister species, another CAS |
| frankincense absolute (10 suppliers) | The absolute version |
| frankincense gum (9 suppliers) | The raw resin tears |
| frankincense resin (7 suppliers) | Resin lumps, 400 hours (measured at 20%) |
Three CAS sets hide in this table: one for the oil and absolute, one for the resin family, and one for Indian frankincense (Boswellia serrata). Boswellia is a genus with several resin-producing species, so read the botanical name when buying — one more round of the names-versus-things lesson for naturals.
When you smell it
- To our noses, the oil opens on lemon peel and pepper brightness, moves through pine resin and green, and only in the tail does the quiet incense surface. It is clearer than expected: the "church smoke" is the smell of burning resin, and the oil itself is much younger.
- Evaluate at 10% or less (the database's own note). For the "church version," buy whole resin tears and warm them on a burner — a different experience from the oil, and the two don't compete.
- Smelling it beside labdanum shows the two poles of resins: sweet, thick amber on one side, bright terpenes on the other.
Regulatory
Listed in GRAS, JECFA, FEMA GRAS, and IFRA. These listings do not provide use limits. Natural oil composition drifts with origin and batch, so check current IFRA Standards and the supplier's specification for skin-bound formulas; oxidized oils are harsher on skin (general care advice), and the low-flash-point storage notes are above.
Buying notes
- Decide on the experience first: oil or resinoid for perfumery, whole resin tears for burning. The two paths don't conflict, and many people end up with both.
- Read the botanical name and origin on the specification: Boswellia has many species, and both price and smell follow the Latin name.
- The oil's flash point is low; in summer check the cap seal on arrival and store away from heat (practical knowledge).
→ Frankincense oil in the database: full physical data, supplier list, suggested pairings. → Frankincense resinoid | Labdanum | Search by scent: try "incense resinous pine" to find its neighbors.
References
C. Cerutti-Delasalle, M. Mehiri, C. Cagliero, P. Rubiolo, C. Bicchi, U. J. Meierhenrich & N. Baldovini, The (+)-cis- and (+)-trans-Olibanic Acids: Key Odorants of Frankincense, Angewandte Chemie International Edition, 55(44), 13719–13723 (2016). PMID 27699963
R. Kumar & S. Tiwari, Geospatial analysis of impact of climate change on potential habitat of Boswellia serrata Roxb. Ex Colebr in Eastern India, Environmental Monitoring and Assessment, 197(7), 720 (2025). PMID 40457122