What Is Citronellic Acid?
Citronellic acid is an aroma ingredient first noted by chemists in the early 1900s during work on the citronella plant and its derivatives. Today it is produced on an industrial scale by carefully oxidizing citronellol, a naturally occurring alcohol found in many essential oils. The process is carried out under controlled conditions to reach a purity level that suits modern fragrance standards.
Although its starting material is natural, the finished product is classed as nature-identical synthetic. This approach guarantees stable quality from batch to batch and keeps supply reliable throughout the year.
At room temperature the material shows up as a clear mobile liquid with a slight hint of yellow. It pours easily thanks to a medium-low viscosity and sits just under water in density. In perfumery labs it is regarded as a workhorse ingredient that appears in a wide range of formulas from fine fragrance to household care. Because the manufacturing route is straightforward and feedstocks are common, it tends to sit in the lower price band on a perfumer’s palette.
What Does Citronellic Acid Smell Like?
Perfumers file citronellic acid under the leathery family.
On a smelling strip it opens with a bold fatty warmth that quickly settles into a supple leather effect. There is nothing sharp or smoky about it. Instead it feels rounded and slightly waxy, almost like well-conditioned hide warmed by the sun. A faint creamy nuance lingers underneath giving a soft cushion to the power on top.
Citronellic acid behaves as a base note. Its molecular weight lets it dry on the blotter for a long time and it anchors lighter notes in a blend. Expect minimal movement in the first few hours followed by a slow fade that can still be detected the next day.
Projection is moderate. It does not leap off the skin but creates a steady aura that stays close enough for comfort. Longevity is excellent especially in oily or solid formats where the material can continue to release its scent over many hours.
How & Where To Use Citronellic Acid
This is a fun material to handle: it behaves well on the blotter, blends smoothly and does not bite your nose while you weigh it out.
Perfumers reach for citronellic acid when they need a warm supple leather note without the smoke or tar that comes with birch tar or isobutyl quinoline. It slides neatly into suede accords, reinforces tobacco styles and adds body to gourmand bases that risk feeling too sweet. In chypres or fougères it can deepen the mossy base and extend wear time.
The ingredient also shines in functional products where costly leather notes are rare. A small dose in fabric softener lends a luxurious warmth, while in candles it provides a cozy skin-like backdrop that survives the heat of the flame.
Typical usage sits between traces and 1 % in fine fragrance, up to 3 % in soaps or detergents and rarely more than 5 % in any application. At very low levels it simply rounds off sharp edges and adds creaminess. As the concentration rises the fatty warmth becomes more obvious, then finally tips into an almost waxy hide effect that can dominate if unchecked.
Citronellic acid is technically an acid, so it may need pre dilution in ethanol or dipropylene glycol before weighing into a base rich in alkalines. This stops possible salt formation that could cloud the concentrate. Otherwise it is plug-and-play: no antioxidants or stabilisers are normally required.
Safety Information
Like all aroma chemicals citronellic acid calls for sensible handling and a few simple precautions.
- Always dilute before evaluation: prepare a 10 % solution in alcohol or a smelling strip to reduce vapor load and avoid nose fatigue.
- Never smell straight from the bottle: undiluted headspace can irritate nasal passages and mask finer nuances.
- Use good ventilation: work near a fume hood or open window to stop heavy vapours building up.
- Wear gloves and safety glasses: protect skin and eyes from accidental splashes.
- Health considerations: some users may experience irritation or sensitisation. Seek medical advice before handling if pregnant or breastfeeding and avoid prolonged high level exposure.
For complete peace of mind always consult the latest safety data sheet from your supplier and follow current IFRA guidelines for maximum usage levels. Documentation is updated regularly so keep an eye on any revisions.
Storage And Disposal
When kept in good conditions citronellic acid stays within spec for roughly three years from manufacture. Many perfumers still find it usable past that if the odor remains unchanged but plan on refreshing stock every few seasons to be safe.
A lab fridge can stretch the shelf life yet it is not essential. A cool dark cupboard away from sunlight and hot equipment works fine. Heat speeds oxidation and can build pressure in the bottle so avoid storing near radiators or windowsills.
Fit bottles with polycone caps for the best seal. These liners grip the neck and block air better than dropper tops which also soak up scent. Skip droppers altogether and decant with pipettes when needed.
Keep containers topped up whenever practical. A smaller air gap means less oxygen to dull the scent and shift the color.
Label every bottle clearly with the ingredient name batch date and hazard icons. Clear labeling cuts mix-ups and keeps the workspace compliant.
Citronellic acid is readily biodegradable so the rinse from pipettes can go down the drain with plenty of water unless local rules forbid it. Larger amounts or outdated stock belong with a licensed chemical disposal service or a household hazardous waste centre. Never pour bulk leftovers into sinks or general rubbish.
Sop up spills with paper towels place them in a sealed bag then treat as chemical waste. Ventilate the room until the fatty leather note has gone.
Summary
Citronellic acid is a nature identical leather note produced by oxidising citronellol. It appears as a clear pale liquid that smells warm fatty and softly leathery.
It works as a smooth base note that anchors fragile accords rounds off rough edges and fits suede tobacco gourmand or mossy builds along with soaps detergents and candles.
Easy to blend and attractively priced it has earned a regular spot in many creative kits. Just store it cool keep the cap tight and remember its bold character can rule a formula if you let usage climb too high.