Definition
Oil concentration is the proportion of fragrant compound (the pure olfactory formula, minus solvent) in the finished juice, usually expressed as a percentage of volume or weight. That proportion is what ties a perfume to a commercial category. The usual ranges, indicative and not legally standardized, place eau de cologne around 2 to 5%, eau de toilette around 5 to 15%, eau de parfum around 15 to 20%, and extrait de parfum around 20 to 40%.
It must be stressed from the outset: these thresholds are industry conventions, not regulatory definitions. No law requires an eau de parfum to be more concentrated than an eau de toilette, and each house interprets these labels in its own way.
Real Effects and Non-Legal Status
Concentration influences several traits, but never mechanically. Longevity generally rises with concentration, without a strict proportion. Projection can paradoxically fall at very high concentrations, because alcohol, the engine of diffusion, is scarcer there: a dense extrait may sit close to the skin while a more alcoholic eau de toilette "snaps" harder on opening. The olfactory profile itself changes: the same formula does not read the same as an eau de toilette and as an extrait, because dilution shifts the balance between light and heavy notes.
The crucial point is the status of these percentages. They are neither defined nor policed by any standard: the exact percentage need not appear on the packaging, and nothing obliges a house to respect the ranges above. As a result, one house's eau de parfum can be less concentrated than another's eau de toilette. Decorative labels (elixir, extreme, intense, absolu) escape any standard just as thoroughly and belong to marketing.
Concentration by Category (Usual Ranges)
The table below sums up the ranges commonly relayed. They are indicative and not legal: read them as an order of magnitude, not a guarantee.
| Category | Usual concentration | Indicative longevity |
|---|---|---|
| Eau de cologne | 2 to 5% | 2 to 3 hours |
| Eau de toilette | 5 to 15% | 3 to 5 hours |
| Eau de parfum | 15 to 20% | 5 to 8 hours |
| Extrait / parfum | 20 to 40% | 8 to 12 hours and up |
Some houses still use intermediate labels (eau fraiche, strong cologne, elixir) whose levels remain specific to each brand, with no common reference.
The Osmetheca View
The public very widely believes these percentages are regulated. They are not. This is probably the most common misunderstanding in all of perfume culture: people pay more for an eau de parfum thinking they buy a concentration guarantee, when they mostly buy a label. An eau de parfum can perfectly well be less concentrated, less tenacious, and less powerful than another house's eau de toilette, or even the same house's.
Osmetheca therefore refuses to assert a precise percentage for a given perfume without an official source from the house, and always presents these ranges as conventions, never as legal thresholds. The concentration level is only one factor in performance, alongside the palette, the fixatives, and the skin. Judging a perfume by its category alone is mistaking the label for the contents.
See Also
Sources
- Société Française des Parfumeurs, parfumeurs.fr, concentration categories.
- ISIPCA, training in formulation and concentrations.
- Basenotes, discussions on the absence of a concentration standard.
- Ellena, J.-C. Perfume: The Alchemy of Scent. Arcade Publishing, 2011 (dilution and categories).