What Is Aldehyde C11 Undecylenic?
Aldehyde C11 Undecylenic is an aroma molecule belonging to the long-chain aldehyde family. The best-known producer is Givaudan, yet other flavour and fragrance suppliers often offer their own equivalent under generic names. The material is typically created by controlled oxidation of an eleven-carbon fatty alcohol that originates from plant oils, yielding a high-purity aldehyde suitable for perfumery use.
At room temperature the ingredient is a clear, colorless liquid that looks a little thicker than water. Despite its pristine appearance it delivers a bold smell that is instantly recognizable to anyone familiar with classic aldehydic fragrances. It is widely used in household and fine fragrance applications, especially in floral, citrus and spicy compositions where a sparkling lift is required.
Availability is generally good and the price sits in the moderate bracket, making it accessible to both large industrial blenders and small artisan perfumers. When stored correctly in a full, well-sealed amber glass bottle kept away from heat and light the aldehyde usually retains acceptable olfactory quality for about two years, sometimes longer if refrigerated. Once the bottle has been opened oxidation will slowly dull the brightness, so many perfumers purchase only the amount they expect to use within a season.
Aldehyde C11 Undecylenic’s Scent Description
This material is most often grouped within the citrus aldehydic family. Off a blotter the first impression is a fizzy burst of orange peel and mandarin zest wrapped in a waxy, almost metallic shimmer that recalls freshly ironed linen. Within seconds a subtle rosy nuance and a delicate green floral note emerge, giving the aroma more depth than a simple citrus splash. A faint soapy facet lingers underneath, hinting at the ingredient’s famous role in classic floral aldehydic perfumes.
Aldehyde C11 Undecylenic behaves like a top note yet it refuses to disappear quickly. It flashes brightly within the first few minutes, settles into the heart during the first hour and can still be detected after several hours, especially on porous materials such as paper or fabric. Its projection is strong at low doses, which is why perfumers often keep the usage level below one percent of the concentrate. On a blotter the scent can be smelled for several days, gradually fading into a soft clean whisper.
How & Where To Use Aldehyde C11 Undecylenic
Perfumers reach for Aldehyde C11 Undecylenic when they want a quick spark of citrus that still feels elegant and slightly floral. It slips easily into orange blossom, rose or muguet accords where a lift is needed without turning sharp or waxy. In a classic soapy aldehydic top note it pairs well with Aldehyde C10 and C12 MNA, yet it can also freshen spicy blends built around clove or cinnamon.
Its sweet spot sits between 0.05 % and 0.5 % of the total formula. At a trace level it simply adds a sunny shimmer that most people cannot pick out on its own. Raise the dose toward 1 % and the orange peel character becomes obvious, sometimes crowding lighter florals. Rarely does a perfumer push it to 2 % but functional products like detergents can handle higher levels thanks to their large dilution in use.
The perceived smell changes with concentration. In tiny amounts the material smells like clean linen kissed with citrus. At moderate strength a more rosy green edge appears. Beyond that the fatty side grows, and if overdosed the note can feel oily or even metallic, dragging the whole perfume off balance.
Aldehyde C11 Undecylenic shines in formats that reward quick bloom and good substantivity such as soaps, shampoos and fabric conditioners. It is less suited to very dry fine fragrances that aim for muted elegance because its throw can feel too “loud” in that setting.
When blending, dilute it to 10 % in ethanol or dipropylene glycol before weighing. The neat material clings to glassware and can throw off small-scale weighing. Pre-dilution also softens the impact during smelling sessions, helping you judge its effect more accurately.
A short rest period after adding it to a perfume base is wise. Give the mix an hour or two to settle so the aldehyde melts into the other notes. This prevents a false first impression that might lead to unnecessary tweaks.
Safely Using Aldehyde C11 Undecylenic
Dilution is key. Always make a working solution before smelling or blending to avoid overwhelming your nose. Avoid direct sniffing from the bottle because neat vapors can irritate the mucous membranes. Work in a well-ventilated space so airborne particles disperse quickly. Wear disposable gloves and safety glasses as a basic barrier for skin and eyes.
Like many aroma chemicals, Aldehyde C11 Undecylenic can cause skin irritation or trigger allergies in sensitive individuals. If you are pregnant or breastfeeding consult a health professional before handling any fragrance raw material. Brief contact with low concentrations is generally considered safe but repeated or high-level exposure increases the risk of irritation or respiratory discomfort.
Wipe spills promptly with a disposable cloth, then wash the area with mild detergent and water. Keep the bottle tightly closed when not in use, store it in a cool dark place and label all dilutions clearly to prevent mix-ups.
For disposal, small leftover amounts can be absorbed onto paper towel and placed in chemical waste. Larger volumes should go through a licensed waste handler that accepts organic solvents.
Always review the latest safety data sheet supplied by your vendor and check back regularly because revisions are common. Follow the current IFRA guidelines for maximum usage in each product type to keep your creations both compliant and safe.
How To Store & Dispose of Aldehyde C11 Undecylenic
Store the neat material in airtight amber glass bottles kept in a cool dark cupboard away from direct sunlight and any heat source. Refrigeration is optional yet helpful for extending shelf life, especially if you plan to keep the bottle longer than a year. If you chill it, allow the liquid to reach room temperature before opening to prevent moisture from condensing inside.
Choose polycone caps for both the stock bottle and all working dilutions. The cone liner forms a tight seal that limits oxygen ingress far better than dropper tops which can leak and let vapour escape. Top up containers whenever practical so there is minimal headspace, as extra air accelerates oxidation and dulls the bright citrus note.
Dilutions stored in plastic should only sit for short periods because aldehydes can migrate into some polymers. Glass is safer for anything you mean to keep on hand. Clearly label every container with the ingredient name, its concentration, the date it was mixed and any hazard statements shown on the safety data sheet. Good labeling prevents mix-ups and speeds response if an accident occurs.
In terms of disposal Aldehyde C11 Undecylenic is considered readily biodegradable yet it can still harm aquatic life when poured straight down the drain. Small residues can be blotted onto paper towel, sealed in a plastic bag and placed in chemical waste. Larger quantities or expired stock should go to a licensed disposal company that handles organic solvents. Rinse empty bottles with a little alcohol, add the rinse to your waste container then recycle the clean glass if local rules allow.
Summary
Aldehyde C11 Undecylenic is a colourless liquid aroma chemical that delivers a lively blend of citrus, floral and green facets with a subtle rosy backdrop. Used at low levels it brightens almost any accord, while higher doses lend a distinct orange zest punch that lasts for days on a blotter. Its friendly price, good performance in soap and fabric care and compatibility with other aldehydes have made it a staple tool for both fine fragrance and functional formulas.
The molecule offers solid stability under normal storage yet it can oxidise when exposed to air or high pH so keep bottles full and tightly sealed. At up to one percent of a perfume concentrate it rarely causes cost issues, though its very specific character means a heavy hand can overshadow delicate notes.
Commercial quantities come directly from Givaudan or from distributors that carry Givaudan’s portfolio. Hobbyists and small brands can source it through specialised online shops and third-party suppliers that repackage larger drums into manageable sizes, often at ten percent dilution for easier dosing.