Ingredient review
Undecenal Cyanoacetate
INCI: UNDECENAL/CYANO-ACETATIC ACID
A synthetic fragrance ingredient that adds a fresh scent but may cause irritation in sensitive individuals.
In plain English
Undecenal Cyanoacetate is a man-made chemical used in cosmetics to create a fresh, citrus-like smell. It belongs to a group of fragrance ingredients that are added in tiny amounts because they are very potent. While it makes products smell nice, it can sometimes irritate sensitive skin or trigger allergic reactions, especially in people who are prone to fragrance sensitivities.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Main practical flags: irritation is moderate; clogging risk is low.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- moderate
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Undecenal Cyanoacetate can be useful, but watch for some irritation potential.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Undecenal Cyanoacetate.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
moderateCan bother some users, especially with frequent use, damaged skin, or strong companion ingredients.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
A synthetic fragrance compound formed by reacting undecenal (an aldehyde) with cyanoacetic acid. It is not a natural extract but a lab-created molecule designed to deliver a specific scent profile.
How it works
In a cosmetic product, Undecenal Cyanoacetate acts solely as a fragrance ingredient. It evaporates from the skin after application, releasing its scent molecules into the air. It does not provide any skincare benefits like moisturizing or anti-aging.
Pros
Pleasant scent
Adds a fresh, citrusy aroma that can make your skincare routine feel more enjoyable and luxurious.
Low concentration needed
Only a tiny amount is required to achieve the desired fragrance, so it doesn't take up much space in the formula.
Cons and cautions
Potential irritant
Can cause redness, stinging, or itching on sensitive skin, especially with repeated use.
Allergen risk
As a synthetic fragrance, it may trigger allergic contact dermatitis in people with fragrance sensitivities.
Best for
- People who enjoy scented skincare and have no history of fragrance allergies
- Those looking for a fresh, uplifting scent in their routine
Use caution if
- Individuals with sensitive, reactive, or eczema-prone skin
- Anyone with a known allergy to synthetic fragrances or aldehydes
Usage tips
Safety summary
Undecenal Cyanoacetate is considered safe for most people when used at low concentrations in cosmetics. However, it carries a moderate risk of skin irritation and allergic reactions, particularly for those with sensitive skin or fragrance allergies. The Cosmetic Ingredient Review (CIR) panel has not specifically evaluated this ingredient, but similar fragrance aldehydes have been deemed safe with restrictions.
Research notes
Research on Undecenal Cyanoacetate specifically is limited. Studies on related fragrance aldehydes indicate that they can cause sensitization in some individuals. The EU Scientific Committee on Consumer Safety (SCCS) has reviewed similar compounds and recommends low usage limits to minimize allergy risks.
Common label clues
- Typical concentration
- Typically used at very low levels (under 1%) due to its strong scent and potential for skin sensitization.
- Regulatory status
- Approved for use in cosmetics in the EU and US, but subject to general fragrance safety guidelines. No specific concentration limits are set, but manufacturers are expected to follow good manufacturing practices and safety assessments.
- Common uses
- Fragranced skincare, Perfumes, Body lotions, Cleansers
- Environmental note
- As a synthetic compound, its environmental impact is not well-studied. It is not biodegradable in the same way as natural fragrances, but its low usage levels may limit environmental accumulation.
Good to know
- This ingredient is often not listed separately on labels; it may be hidden under 'fragrance' or 'parfum'.
- Regulatory bodies like the EU CosIng database require labeling of certain fragrance allergens, but Undecenal Cyanoacetate is not currently on that specific list.
Common questions
What is Undecenal Cyanoacetate in beauty products?
Undecenal Cyanoacetate is a man-made chemical used in cosmetics to create a fresh, citrus-like smell. It belongs to a group of fragrance ingredients that are added in tiny amounts because they are very potent. While it makes products smell nice, it can sometimes irritate sensitive skin or trigger allergic reactions, especially in people who are prone to fragrance sensitivities.
What does Undecenal Cyanoacetate do in a beauty product?
In a cosmetic product, Undecenal Cyanoacetate acts solely as a fragrance ingredient. It evaporates from the skin after application, releasing its scent molecules into the air. It does not provide any skincare benefits like moisturizing or anti-aging.
Is Undecenal Cyanoacetate safe for most people?
Undecenal Cyanoacetate is considered safe for most people when used at low concentrations in cosmetics. However, it carries a moderate risk of skin irritation and allergic reactions, particularly for those with sensitive skin or fragrance allergies. The Cosmetic Ingredient Review (CIR) panel has not specifically evaluated this ingredient, but similar fragrance aldehydes have been deemed safe with restrictions.
Who should be careful with Undecenal Cyanoacetate?
Individuals with sensitive, reactive, or eczema-prone skin Anyone with a known allergy to synthetic fragrances or aldehydes
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.