Ingredient review

2-Ethylidenedecanal

INCI: 2-ETHYLIDENEDECANAL

A synthetic fragrance ingredient that adds a fresh scent but may cause skin irritation in sensitive individuals.

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In plain English

2-Ethylidenedecanal is a man-made chemical used to give skincare products a fresh, citrusy smell. It belongs to a group of fragrance ingredients called aldehydes, which are common in perfumes and scented lotions. While it makes products smell nice, it can sometimes irritate sensitive skin, especially if used in high amounts.

Quick decision guide

Useful, but context matters

2-Ethylidenedecanal 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.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging 2-Ethylidenedecanal.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. 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

moderate

Can bother some users, especially with frequent use, damaged skin, or strong companion ingredients.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

A synthetic aldehyde compound created in a lab, used primarily as a fragrance ingredient in cosmetics and personal care products.

How it works

It works by evaporating from the skin and interacting with scent receptors in the nose, providing a pleasant fragrance experience. In a product, it does not actively treat the skin but contributes to the sensory appeal.

Pros

Pleasant scent

Adds a fresh, citrusy fragrance that can make your skincare routine more enjoyable.

Low comedogenic risk

Unlikely to clog pores, making it suitable for most skin types in terms of acne risk.

Cons and cautions

Potential irritant

Can cause redness, stinging, or irritation, especially on sensitive or compromised skin.

Allergen concern

Classified as a potential allergen by regulatory bodies; may trigger contact dermatitis in susceptible individuals.

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 fragrance or aldehydes

Usage tips

Patch test any new product containing this ingredient on a small area of skin before full use.
If you have sensitive skin, opt for fragrance-free products to avoid potential irritation.

Safety summary

Generally considered safe for most people at low concentrations, but can cause skin irritation and allergic reactions in sensitive individuals. Regulatory bodies require labeling due to allergen potential.

Research notes

Studies show that aldehydes like 2-ethylidenedecanal can be skin sensitizers. The EU Scientific Committee on Consumer Safety (SCCS) has reviewed similar aldehydes and recommends safe use limits. More research is needed on long-term exposure.

Common label clues

Typical concentration
Typically used at very low concentrations (under 1%) as a fragrance component.
Regulatory status
Approved for use in cosmetics in most regions, but must be listed on the label if present above 0.001% in leave-on products and 0.01% in rinse-off products in the EU due to allergen concerns.
Common uses
Fragranced skincare, Perfumes, Body lotions, Cleansers
Environmental note
As a synthetic compound, its environmental impact depends on production methods and disposal; limited data on biodegradability.

Good to know

  • This ingredient is often listed under 'fragrance' or 'parfum' on labels, so it may not appear by name.
  • Regulations in the EU require this ingredient to be labeled separately if present above certain levels due to allergen potential.

Common questions

What is 2-Ethylidenedecanal in beauty products?

2-Ethylidenedecanal is a man-made chemical used to give skincare products a fresh, citrusy smell. It belongs to a group of fragrance ingredients called aldehydes, which are common in perfumes and scented lotions. While it makes products smell nice, it can sometimes irritate sensitive skin, especially if used in high amounts.

What does 2-Ethylidenedecanal do in a beauty product?

It works by evaporating from the skin and interacting with scent receptors in the nose, providing a pleasant fragrance experience. In a product, it does not actively treat the skin but contributes to the sensory appeal.

Is 2-Ethylidenedecanal safe for most people?

Generally considered safe for most people at low concentrations, but can cause skin irritation and allergic reactions in sensitive individuals. Regulatory bodies require labeling due to allergen potential.

Who should be careful with 2-Ethylidenedecanal?

Individuals with sensitive, reactive, or eczema-prone skin Anyone with a known allergy to fragrance or aldehydes

Research sources

European Commission - CosIng DatabaseOpenPubMed - Aldehyde skin sensitization studyOpenFDA - Fragrance ingredients in cosmeticsOpen

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.