In short
Birch tar oil is made by destructive distillation of birch wood and bark, then rectified. It gives the smoky, tarry smell of traditional Russian leather.
What Birch Tar Oil (Rectified) smells like
Rectified birch tar oil smells of bonfire, burnt rubber and smoked leather, in a perfumery glossary, and carries the smoked-leather note behind Russian Leather accords; the same glossary finds birch tar sharper and more aggressive than cade, which is rounder and more resinous. Forum perfumers find birch tar the more leathery of the two, with a sausage-like nuance, against cade's smoked-fish phenolic note. Crude birch tar is rich in polycyclic aromatic hydrocarbons and is rectified before perfumery use to meet IFRA limits.
- Leading note
- Smoked leather
- Clear facets
- Tarry, phenolic
- Supporting facets
- Burnt rubber
- Faint facets
- Smoked meat
- Character
- Sharp, dark, powerful
What makes Birch Tar Oil (Rectified) distinctive
The Russian Leather note: tar and smoke that read as tanned hide.
Where the descriptions disagree: Glossaries disagree on which of birch tar and cade is the harsher.
How Birch Tar Oil (Rectified) is used
Used in traces in leather, smoky and chypre compositions; only rectified grades meeting IFRA limits are used.
Typical role: modifier (used in small amounts to change the character of a blend).
How Birch Tar Oil (Rectified) differs from similar materials
- Cade Oil (Rectified)
- Cade is described as more medicinal, phenolic and smoky — campfire ash, smoked fish — where birch tar is the more leathery. (compared directly by a cited source)
- Isobutyl Quinoline
- The butyl quinolines are an earthy, green-mossy leather without the tar and smoke; birch tar is the smoked leather.
- Guaiacol
- Fraterworks suggests guaiacol, a single smoky-phenolic molecule, where birch tar would be too powerful for the smoke note wanted. (compared directly by a cited source)
An asterisk marks a difference that a cited source states directly. The others compare the published descriptions of each material. Smell varies with grade, supplier and dilution; compare them side by side on blotters before substituting one for another.
Formulation considerations
Only rectified grades meeting the IFRA specification for birch wood pyrolysate should be used. Very powerful and persistent.
Identity and classification
- Type
- Essential oil
- Origin
- Natural
- Odour family
- Leather / Woody
- Note position
- Base note
- Physical form at room temperature
- Liquid
- Also known as
- Birch wood pyrolysate
- Botanical source
- Betula pendula
- CAS number
- 8001-88-5
The CAS number was checked on 19 October 2026 against a PubChem substance record that gives it for this material. A natural material is a mixture, so it has no single formula; its composition varies with origin and processing.
Safety and compliance
The IFRA Standards Library lists a Standard covering Birch Tar Oil (Rectified):
- "Birch wood pyrolysate" — type not stated in the library listing, 47th Amendment, published 2013-08
Limits differ by product category and are set out in the Standard itself; this page does not reproduce them. The list above reflects the library as read on 19 October 2026.
This page is general information, not a safety assessment or a specification. Confirm identity, composition, IFRA status and allergen content from your supplier's documents for the lot you hold.
Materials it works with
-
Guaiacol
Aroma chemical · Leather / Woody — smoky, phenolic, medicinal, woody
-
4-Ethylguaiacol
Aroma chemical · Leather / Spicy — smoky, clove, bacon, phenolic
-
Cade Oil (Rectified)
Essential oil · Leather / Woody — smoky, tarry, leathery, woody
-
Isobutyl Quinoline
Aroma chemical · Leather / Green — leathery, earthy, green, smoky
Birch Tar Oil (Rectified) is also suggested as a partner on the pages for 3,4-Xylenol, Castoreum Absolute, Suederal and Syringol.
Used in formulas and accords
Used in 21 published formulas
Birch Tar Oil (Rectified) is an ingredient in 19 perfume formulas and 2 accords in the Formula & Accord Library.
RUŌOD House Originals
Original compositions by RUŌOD House.
Further reading
Questions about Birch Tar Oil (Rectified)
Is Birch Tar Oil (Rectified) natural or synthetic?
Birch Tar Oil (Rectified) is natural. It is a volatile oil obtained from plant material by steam distillation or, for citrus peels, by cold expression.
What is the CAS number of Birch Tar Oil (Rectified)?
8001-88-5, the registry number for the essential oil as a substance rather than a single molecule. It was checked against PubChem on 19 October 2026.
Which published formulas use Birch Tar Oil (Rectified)?
Birch Tar Oil (Rectified) is used in 21 published formulas in the RUŌOD Lab Formula & Accord Library, including Asphalt Peony, Birch Ghost and Bitter Bridle. Each is listed with a link under "Used in formulas and accords" on this page.
Is Birch Tar Oil (Rectified) covered by an IFRA Standard?
Yes. The IFRA Standards Library lists a Standard covering it: "Birch wood pyrolysate" — type not stated in the library listing, 47th Amendment. The limits depend on the product category; read the Standard itself before formulating.
Sources
- PubChem — substance 135280026, checked 19 October 2026.
- IFRA — Standards Library, read 19 October 2026.
- Premiere Peau — Tar — published perfumery reference.
- Basenotes — Campfire smoke aroma chemical (forum) — published perfumery reference.
- Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 21 October 2026. Evidence: more than one published description. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.