ISO E Super® – from Fahrenheit to Molecule 01
ISO E Super® by IFF – The Complete Reference
ISO E Super® is one of the best-known and most-discussed perfumery molecules of the present day. It stands behind some of the most influential fragrances of recent decades – and is at the same time one of the least understood materials in DIY perfumery. This page summarizes everything perfumers and formulators should know.
Contents
- What is ISO E Super®?
- Chemistry – a mixture, not a single molecule
- ISO E Super® and its analogues
- What does ISO E Super® smell like?
- The halo effect
- Dosage and effect
- In practice – dissolving, storing, combining
- History – from Fahrenheit to Molecule 01
- IFRA status and regulation
- Frequently asked questions
1. What is ISO E Super®?
ISO E Super® is a synthetic aroma material by IFF (International Flavors & Fragrances) from the group of iso-cyclo compounds. Its full chemical name is 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-one – in short: a polycyclic ketone with a characteristic woody-cedar signature.
Strictly speaking, ISO E Super® is not a single molecule. It is a complex mixture of isomers – different spatial arrangements of the same atoms. It is precisely this mixture that makes it one of the most fascinating and, at the same time, most difficult-to-describe raw materials in perfumery.
According to IFF, ISO E Super® is stabilized with 0.15% tocopherol – an antioxidant that ensures the shelf life of the liquid raw-material mixture.
2. Chemistry – a mixture, not a single molecule
This section is the key to understanding ISO E Super®.
When IFF chemists John B. Hall and James M. Sanders developed the molecule in 1973, they patented a compound called Isocyclemone E. The commercially produced version – ISO E Super® – turned out, however, on closer examination to be something else: a complex isomer mixture.
Givaudan chemists discovered in the 1990s that the main molecule of the mixture has an odor threshold of about 500 ng/L. It barely smells.
The smell of ISO E Super® is determined to a large extent by a by-product: Arborone (also called Iso E Super Plus). Arborone makes up only about 5% of commercial ISO E Super® – but has an odor threshold of 0.005 ng/L. That is 100,000 times stronger than the main molecule.
Despite decades of research, it has so far not been possible to produce Arborone in industrial quantities. Various manufacturers have developed variants with a higher Arborone content:
- ISO E Super® – IFF (original, approx. 5% Arborone)
- Timbersilk – IFF (higher gamma-isomer content)
- Sylvamber – DRT (higher Arborone content)
Trade names and synonyms for ISO E Super®:
- OTNE (Octahydrotetramethyl Acetophenone)
- Isocyclemone E
- Patchouli Ethanone
- Tetramethyl Acetyloctahydronaphthalenes
- Amberfleur, Orbitone, Anthamber, Ambroise Super
3. ISO E Super® and its analogues – a whole molecular family
ISO E Super® is a registered trademark of IFF. Only IFF's product carries this name with the ® symbol. In practice, however, the term ISO E Super is often used as a generic label – for all materials of this molecular class, regardless of manufacturer.
In practice this leads to misunderstandings: anyone who buys ISO E Super somewhere without knowing where it comes from does not always know what they are actually getting. The isomer distribution, the Arborone content and thus the odor profile can vary considerably from product to product.
At the same time, this means there is a whole family of related materials – each with its own character, its own strengths and its own nuances. None of them is a simple copy. Each deserves its own place in the formula.
Overview of the most important materials of this family:
- ISO E Super® (CAS 54464-57-2 / 68155-66-8) – IFF. The original. Approx. 5% Arborone content. Soft, velvety, versatile.
- Timbersilk – IFF. Higher gamma-isomer content. Clearer, stronger, more direct in its woody character.
- Sylvamber – DRT. Higher Arborone content. More intense, drier profile.
- Amberfleur – chemically the same molecular class as ISO E Super® (CAS 54464-57-2), merely under a different trade name; available in our range as an alternative.
- Methylcyclomercitone – drier, woodier profile. More strongly structured, less velvety than ISO E Super®.
- Georgywood (CAS 185429-83-8, C₁₆H₂₆O, MW 234.4) – an isomer of the iso-cyclo family with its own characteristic woody profile.
For the perfumer this means: it is worth trying and comparing different materials of this family. What achieves a certain effect in a formula with ISO E Super® can take on a different – sometimes more interesting – dimension with Sylvamber or Methylcyclomercitone. The materials complement each other; they do not replace one another.
4. What does ISO E Super® smell like?
ISO E Super® is hard to describe – and that is no coincidence. It is a raw material that affects different people very differently and that fundamentally changes its character depending on concentration.
IFF officially describes the profile as smooth, woody, amber – with unique aspects that create a velvety texture.
ISO E Super® is perceived as:
- dry cedarwood
- velvety woodiness
- warm mineral facets
- floral-woody nuances
- a light ambery depth
- subtle skin warmth
- animalic warmth at high dosages
- a long-lasting drydown
A well-known phenomenon: many people can barely smell ISO E Super® from the bottle. This is because Arborone – the most odor-active component – comes across less on the blotter than on the skin. On the skin it unfolds through body warmth and skin chemistry into a characteristic woody-cedar aura.
Geza Schön, perfumer and founder of Escentric Molecules, described the effect of ISO E Super® as hypnotic and irresistible – a scent one wants more and more of. On it he built Molecule 01 – a perfume made from a single ingredient that became a cult brand.
5. The halo effect
The halo effect is one of the most important properties of ISO E Super® – and one of the reasons it is used in so many formulas.
The term describes the following phenomenon: ISO E Super® at low dosages makes other aroma materials more like themselves. It reinforces and deepens other notes without being perceptible itself.
A woody accord appears woodier. A floral accord appears more floral. A musk appears deeper and closer to the skin. ISO E Super® acts as an invisible enhancer – an effect rarely found in this form in other raw materials.
At higher dosages, ISO E Super® itself comes to the fore with a characteristic dry, velvety woody signature.
6. Dosage and effect
ISO E Super® is extremely concentration-dependent in its effect:
- 0.5–2% – invisible reinforcement of other notes, halo effect
- 2–5% – subtle woody depth, improves projection and cohesion
- 5–15% – clear ISO E Super® signature, standalone woody-cedar character
- above 15% – dominant molecular character, almost hypnotic effect
In practice, exceptionally high dosages are used:
- Fahrenheit (Christian Dior, 1988) – approx. 25% in the concentrate. First milestone of overdosing
- Terre d'Hermès (Jean-Claude Ellena, 2006) – high ISO E Super® content, shapes the mineral-woody character
- Molecule 01 (Escentric Molecules, 2006) – exclusively ISO E Super® in ethanol
- Féminité du Bois (Shiseido, 1992) – approx. 43% ISO E Super®
For first experiments, a starting point of 1–2% in the concentrate is advisable.
7. In practice – dissolving, storing, combining
Dissolving
- ISO E Super® is a liquid – no dissolving needed
- Readily miscible with ethanol, IPM, DPG and other perfumery solvents
- Directly dosable in formulas
Storing
- Cool, dry, protected from light, tightly closed
- The tocopherol protects against oxidation
- Shelf life: max. 24 months
Synergies
- Ambrofix™ – reinforces the amber-woody depth, creates a warm woody-amber base
- Cashmeran® – warms the character, adds a velvety cashmere note
- Galaxolide 50% in DPG – connects the woodiness with a soft musk
- Sandalwood materials – ISO E Super® markedly reinforces the sandalwood character
- Vetiver – ISO E Super® opens and deepens the earthy character
8. History – from Isocyclemone E to Molecule 01
The history of ISO E Super® begins in the 1960s, when chemists worldwide were researching ionone analogues – compounds with a violet-like scent character.
In 1973, John B. Hall and James M. Sanders of IFF discovered a new compound. They patented it as Isocyclemone E and shortly afterward developed an improved synthesis – ISO E Super®.
At first, ISO E Super® was used only in small amounts. That changed in 1988 with Fahrenheit by Christian Dior: perfumer Jean-Louis Sieuzac used ISO E Super® at around 25% of the concentrate – an unprecedented use up to that point. It was the beginning of the overdosing trend.
In 1992 came Féminité du Bois (Shiseido) with approx. 43% ISO E Super® – Pierre Bourdon and Christopher Sheldrake made wood compositions salon-worthy for women.
In the 1990s, Givaudan chemists discovered the true chemical nature of ISO E Super®: the main molecule barely smells. The scent comes almost exclusively from Arborone – a by-product with a 100,000-fold lower odor threshold.
In 2006, ISO E Super® reached cult status: Molecule 01 by Escentric Molecules – a perfume made from a single molecule, conceived by Geza Schön. Today ISO E Super® is used in almost every second fine fragrance.
9. IFRA status and regulation
ISO E Super® (CAS 54464-57-2 / 68155-66-8) is not subject to any quantity IFRA restrictions in any application category.
Note: ISO E Super® has a high Log Pow (approx. 5.7), which indicates a certain tendency toward bioaccumulation. Check current IFRA Standards and local regulations before use in commercial products.
Frequently asked questions about ISO E Super®
What is ISO E Super®?
ISO E Super® is a synthetic woody-cedar material by IFF – a complex isomer mixture with a characteristic velvety, woody odor profile. It is among the most widely used raw materials in perfumery.
Why does ISO E Super® barely smell from the bottle?
Because the most odor-active component – Arborone – makes up only about 5% of the mixture and comes across less on the blotter than on the skin.
Is ISO E Super® the same as Molecule 01?
No. Molecule 01 uses a special IFF version with a higher gamma-isomer content that is not freely available for sale. ISO E Super® is the standard version.
What is the halo effect?
The halo effect describes the property of ISO E Super® to reinforce other aroma materials at low dosages – without being perceptible itself.
Are there IFRA restrictions for ISO E Super®?
No. ISO E Super® is not subject to any quantity IFRA restrictions in any application category.
What is the difference between ISO E Super® and Timbersilk?
Timbersilk is an IFF variant with a higher gamma-isomer content – stronger and clearer in its woody character. ISO E Super® is the standard version.
What is the difference between ISO E Super® and Amberfleur?
Amberfleur is chemically the same molecular class as ISO E Super® (CAS 54464-57-2) – the same woody-amber molecule, only under a different trade name and from different manufacture. Small differences in isomer distribution and batch are possible. Available in our range as an alternative: Amberfleur →
How do you dose ISO E Super® for first experiments?
A starting point of 1–2% in the concentrate is advisable. That is enough to experience the halo effect without ISO E Super® dominating the composition.