What Is Ethyl Crotonate?
Ethyl Crotonate is the ethyl ester of crotonic acid, first recorded in the mid-1800s during the great wave of ester chemistry that followed the isolation of crotonic acid from plant sources. Today it is produced on an industrial scale by reacting crotonic acid with ethanol in the presence of an acid catalyst, then purifying the result through distillation to achieve a high trans-isomer content.
The finished material is a clear colorless liquid that flows easily at room temperature, looking much like water yet slightly thicker. Because of its low flashpoint it needs careful handling around ignition sources, though it remains chemically stable in regular fragrance formulations.
Ethyl Crotonate is a fully synthetic ingredient even when the feedstocks begin with bio-based ethanol. It is employed by perfumers primarily as a specialty accent rather than a bulk blender, so while it is not rare it also is not among the highest-volume aroma chemicals. Cost-wise it sits in the middle ground; not prohibitive for everyday products yet high enough to discourage overuse in detergent bases.
Its versatility allows formulators to place it in everything from fine fragrance concentrates to functional products like shampoos and candles, giving brands freedom to maintain a consistent olfactive signature across multiple formats.
What Does Ethyl Crotonate Smell Like?
Perfumers group Ethyl Crotonate in the gourmand family, the cluster of notes that recall edible treats and comforting kitchen aromas.
On a blotter the first impression is a glossy caramel note, swiftly joined by a splash of light rum. Within seconds a juicy fruit nuance peeks through, somewhere between dried apricot and candied apple, while an airy almost solvent-like facet keeps the profile from feeling heavy. As the minutes pass a mild tang surfaces, giving a sweet-and-sour edge that prevents the caramel from drifting into syrupy territory.
In the traditional breakdown of a perfume pyramid Ethyl Crotonate behaves as an upper-middle note. It flashes quickly like a top note thanks to its volatility, yet a residue of toffee warmth lingers into the heart of the composition, bridging brighter openings to richer bases.
Projection is assertive in the first half hour, radiating a playful dessert vibe beyond arm’s length. Longevity is moderate; expect the main character to fade after two to three hours on skin, though traces of soft brown sugar may last a little longer when anchored by heavier materials.
How & Where To Use Ethyl Crotonate
Ethyl Crotonate is a fun one to handle: it pours easily, flashes off cleanly and rewards even tiny additions with a burst of caramelized sparkle.
Perfumers reach for it when they need to sweeten a top or early heart without resorting to heavy-handed vanilla. It slips neatly into rum or liquor accords, baked-fruit effects and caramel popcorn signatures where a hint of fermented tang keeps the sweetness alive. In fruity chypres it can lift peach or apricot, while in modern gourmands it bridges juicy openings to toasted praline bases.
Typical inclusion sits anywhere from a trace up to about 2 %, though some confectionery-style fine fragrances tolerate 3 – 5 % in the concentrate. At 0.1 % you mainly get airy rum; around 1 % the caramel expands and a sour edge peeks through; push higher and the material risks smelling onion-like, so balance it with lactones, vanilla or woody ambers.
It performs best in alcohol or solvent based systems but also survives most surfactant formats like shampoo and liquid soap. Very high wash-off levels can dull its nuance so pair it with more substantive sweets such as ethyl maltol or maple lactone for detergents.
No special prep is needed beyond a standard 10 % dilution for evaluation. Because the flashpoint is extremely low keep working solutions sealed and away from hot plates or open flames.
Safely Information
Even though Ethyl Crotonate is widely used certain precautions and considerations are essential when handling it in the lab or studio.
- Always dilute before evaluation: prepare a 1 – 10 % solution in ethanol or dipropylene glycol before smelling to avoid sensory overload.
- Never sniff straight from the bottle: direct inhalation can irritate the nose and mask subtle notes you want to assess.
- Work in a well-ventilated space: good airflow prevents buildup of vapors that could cause headaches or dizziness.
- Wear gloves and safety glasses: contact with undiluted material may dry or irritate skin and eyes.
- Health considerations: some aroma chemicals can trigger irritation or allergic reactions. If you are pregnant or breastfeeding consult a medical professional before prolonged exposure. Brief low-level contact is generally safe but high concentrations or extended handling can be harmful.
For complete peace of mind always consult the latest Safety Data Sheet supplied by your vendor, keep an eye on updates and follow any current IFRA guidelines for maximum usage in finished products.
Storage And Disposal
When kept in the right conditions Ethyl Crotonate stays fresh for roughly two years from the date of purchase. Some suppliers print an 18- to 24-month window on the label but in practice a well-sealed bottle often performs beyond that.
Cold storage stretches the lifespan even further. A household fridge set between 4 °C and 8 °C slows oxidation and evaporation. If fridge space is tight a cool cupboard works almost as well provided the bottle is shielded from sunlight and away from heaters or hot plates.
Use bottles fitted with polycone caps for both neat material and dilutions. The plastic cone inside the cap forms a tight seal that keeps air and moisture out. Dropper tops look handy yet they leak vapor and invite oxygen so reserve them for very short-term use only.
Try to keep each container as full as possible. Filling a smaller bottle once the level drops below half cuts the air gap and reduces the chance of off-notes creeping in.
Label every bottle clearly with the name Ethyl Crotonate, the concentration if it is a dilution, the date it was filled and any key hazard symbols. Clear labeling avoids mix-ups and reminds anyone handling the bottle to read the safety sheet first.
For disposal never pour large amounts straight down the sink. Small residue from rinsing glassware can usually go to drain with plenty of running water but bigger volumes should be collected in a waste solvent can and sent to a licensed disposal service. Ethyl Crotonate is readily biodegradable yet its low flashpoint makes it a fire risk if left in open trash. Wipe spills with absorbent material, seal the wipe in a metal bin then dispose of it according to local rules.
Summary
Ethyl Crotonate is a synthetic ester that delivers an instant hit of caramel rum and soft fruit. It acts like a sweet spark in the early heart of a perfume and slips neatly into liquor accords, baked fruit ideas and modern dessert styles.
Perfumers enjoy its lively nature because a drop or two can brighten a formula without resorting to heavy vanilla. It works across fine fragrance shampoo soap and even candles so brands can keep the same treat-like note in many products.
It is not the cheapest aroma chemical yet the price is low enough for everyday use when handled with care. Stability is good though the low flashpoint demands cool storage and careful handling near heat or flame. Use it thoughtfully, keep an eye on dosage to avoid the onion side effect and you will have a fun reliable tool for countless gourmand creations.