2-Hexenal (CAS 16635-54-4) — Top Note Fragrance Ingredient

ByThe Good Scents



green

2-Hexenal

CAS 16635-54-4

Note
top
Volatility
very high
MW
98.14
Data as of: Jun 2026

What Is 2-Hexenal?

2-Hexenal (CAS 16635-54-4) is an aroma chemical used as a fragrance and flavour ingredient. Its odour is described as apple, fruity and green, placing it within the green family as a top note with very high volatility. With a molecular weight of 98.14 (formula C6H10O), it is handled by perfumers as a building block for compositions where a apple character is desired. The data below is compiled from public chemical and regulatory sources.

Safety Profile

USE WITH AWARENESS

Generally safeUse with awarenessProfessional use
CAS
16635-54-4
Formula
C6H10O
MW
98.14
InChIKey
MBDOYVRWFFCFHM-SNAWJCMRSA-N
2-Hexenal 2D structure

2-Hexenal
C6H10O
Layer 1 · Enthusiast

What Does 2-Hexenal Smell Like?

The odour profile of 2-Hexenal is reported as apple, fruity, green, leafy, fatty. The dominant facet is its apple character, with the remaining notes adding nuance and complexity. As a top note it contributes to the opening of a fragrance. Perceived intensity and exact character depend on concentration, the carrier and the surrounding accord.

Scent Profile

Profile derived from public odour-descriptor data; relative, not absolute.

Layer 2

Chemistry & Properties

The Chemistry

2-Hexenal has the molecular formula C6H10O and a molecular weight of 98.14 g/mol. Its canonical SMILES representation is CCC/C=C/C=O. Its reported log P (XLogP) of 1.50 indicates a moderately polar molecule, which informs how it partitions in a formula. Physical constants below are drawn from PubChem and EPA CompTox public datasets.

Physical & Chemical Properties

Molecular Weight 98.14 g/mol
Boiling Point 146.0 °C
Melting Point -37.62 °C
Flash Point 42.42 °C
Density 0.8291 g/cm³
Vapor Pressure 4.84 mmHg
Water Solubility 0.081 g/L
XLogP 1.50

Perfumer Guide

Note Position
Top
Volatility
Very High
Primary Odour
Apple

Alternatives & Comparisons

Ingredients occupying a similar odour space — useful as substitutes or companions when 2-Hexenal is unavailable or restricted.

1
2-Pentenal CAS 764-39-6

Shares green, leafy, apple character — a candidate substitute or companion in the same odour space.

2
(2E,6Z)-octa-2,6-dienal CAS 76917-23-2

Shares fatty, green, leafy character — a candidate substitute or companion in the same odour space.

3
(E,E)-2,4-Octadien-1-Ol CAS 18409-20-6

Shares green, fruity, leafy character — a candidate substitute or companion in the same odour space.

Layer 3

Safety & Regulatory

⚠ Regulatory Disclaimer

General reference only. IFRA, REACH and EU Cosmetics Regulation standards update periodically. Consult the current IFRA Standards Library before formulating. Not legal or regulatory advice.

IFRA Status

Subject to an IFRA restriction (51st Amendment) — maximum use levels apply by product category. Consult the current IFRA Standards Library before formulating.

GHS Classification

Signal word: Danger

H226H302H311H315H317H319H410
Formulating with 2-Hexenal?

Open 2-Hexenal in Fragrance Studio (Pro) for the calibrated vapour-pressure curve, the modelled odour-threshold estimate, and the substitute-matching engine across 2,900+ aromachemicals.

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References & Sources

  1. PubChem Compound Summary (NIH) — search by InChIKey
  2. EPA CompTox Chemicals Dashboard — physicochemical & fate data
  3. IFRA Standards Library (49th / 51st Amendment)
Sources: PubChem (NIH) · EPA CompTox · IFRA Standards Library · public GHS classification. Odour descriptors are original editorial summaries of public profiles, not reproduced from any single proprietary source.

Data: PubChem (NIH), EPA CompTox, IFRA. Last reviewed: Jun 2026.

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