Common Name(s): 3,7-dimethyl-2,6-octadienal,geranial+neral mix

CAS Number: 5392-40-5

DESCRIPTION

What It Does: Provides the defining intense lemon-citrus fragrance note.

Why It's Used: The lemon scent compound – citral defines the fresh lemon scent in lemon essential oil and lemongrass with potent antimicrobial activity.

How It Works: Mixture of e-isomer (geranial) and z-isomer (neral). antimicrobial via michael addition to thiol enzymes. inhibits nf-kb for anti-inflammatory activity. antioxidant via allylic aldehyde.

Typically Found In: Citrus fragrances,antibacterial products,lemon-scented cosmetics

TECHNICAL DETAILS

Primary Category: Fragrance component – lemon aldehyde

Secondary Functions: Skin conditioning

Application Areas:

Typical Concentration Range: 0.001%–0.5%

SOURCING & ETHICS

Vegan Status: Conditional - supplier confirmation required

Halal Status: Unverified - supplier confirmation required

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier. [audit 2026-07-29 rev2: the record's own source_notes does not assert a non-animal origin, or instructs the reader to verify with the supplier; "yes" asserts knowledge the record does not hold. determination requires shariah-panel sign-off.]

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Eu cosmetics regulation: declared fragrance allergen. high sensitisation potential from alpha,beta-unsaturated aldehyde structure. ifra strict limits.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Citral's high sensitisation potential (llna ec3 ~0.11%) is a consequence of its alpha,beta-unsaturated aldehyde structure providing a highly reactive michael acceptor for skin protein covalent binding. the e/z mixture (geranial/neral) in natural citral means both isomers contribute to the sensitisation burden – explaining why lemongrass oil (very high citral content, ~60-80%) is one of the more common essential oil allergens.

Last Verified: 2026-03-12

Primary Sources: Cosing database,ifra standards