Citronellal
[CAS# 106-23-0]

Identification

• Classification: Flavors and spices >> Synthetic spice >> Aldehyde fragrance >> Nonenal
• Name: Citronellal
• Synonyms: 3,7-Dimethyl-6-octenal; Rhodinal
• Molecular Formula: C₁₀H₁₈O
• Molecular Weight: 154.25
• CAS Registry Number: 106-23-0
• EC Number: 203-376-6
• FEMA: 2307
• SMILES: CC(CCC=C(C)C)CC=O

Properties

• Density: 0.85
• Boiling point: 89 °C (11 torr)
• Refractive index: 1.445-1.45
• Flash point: 78 °C

Safety Data

• Hazard Symbols: GHS07;GHS09 Warning
• Risk Statements: H315-H317-H319-H411
• Safety Statements: P261-P264-P264+P265-P272-P273-P280-P302+P352-P305+P351+P338-P321-P332+P317-P333+P317-P337+P317-P362+P364-P391-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Skin sensitization	Skin Sens.	1	H317
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Skin sensitization	Skin Sens.	1B	H317
Specific target organ toxicity - single exposure	STOT SE	3	H335
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Eye irritation	Eye Irrit.	2A	H319

Discovery and Applications

Citronellal, a monoterpene aldehyde, was first identified in the mid-19th century by the French chemist Ferdinand Tiemann. It was isolated from the essential oils of various aromatic plants, including citronella, lemon-scented gum, and lemongrass. Tiemann's discovery of citronellal marked a significant advancement in the understanding of natural fragrance compounds and their potential applications in perfumery and medicine.

Citronellal is a prominent ingredient in perfumery, valued for its fresh, citrusy scent reminiscent of lemon and citronella. It is widely used in perfumes, colognes, and fragrances for its uplifting and invigorating aroma. Citronellal adds brightness and vibrancy to fragrances, often serving as a top or middle note. Its versatility allows it to blend harmoniously with other citrus, floral, and woody notes, contributing to complex and sophisticated scent compositions.

In the food and beverage industry, citronellal is used as a flavoring agent and natural additive. Its citrusy flavor profile enhances the taste of various products, including candies, beverages, and baked goods. Citronellal is commonly found in lemon-flavored desserts, herbal teas, and confectionery, providing a refreshing and tangy taste.

Citronellal is utilized in aromatherapy for its therapeutic properties and uplifting aroma. It is known for its energizing and mood-enhancing effects, making it valuable for promoting mental clarity and emotional well-being. Citronellal essential oil is diffused or used in massage blends to create an uplifting atmosphere and alleviate stress and fatigue.

Due to its natural insect-repelling properties, citronellal is used in insect repellent formulations. It is effective against mosquitoes, flies, and other insects, making it a popular alternative to synthetic repellents containing DEET. Citronellal-based repellents are commonly found in sprays, lotions, candles, and outdoor products, offering protection against insect bites while enjoying outdoor activities.

Citronellal exhibits potential pharmacological properties, including antimicrobial, antifungal, and anti-inflammatory effects. It is being studied for its therapeutic potential in various medicinal applications, including herbal medicine and traditional remedies. Citronellal may have applications in treating skin conditions, respiratory ailments, and inflammatory disorders.

Citronellal has industrial applications beyond fragrance and flavoring. It is used as a starting material in the synthesis of other compounds, including perfumery ingredients, pharmaceuticals, and specialty chemicals. Its reactivity and versatility make it a valuable intermediate in chemical manufacturing processes, contributing to the production of diverse products across industries.

References

2024. Unveiling the anxiolytic and analgesic effects of citronellal in Swiss mice: in vivo and in silico insights into COX and GABAA receptor pathways. Naunyn-Schmiedeberg's Archives of Pharmacology, 482.
DOI: 10.1007/s00210-024-03665-9

2025. The potency of Cupressus sempervirens and Eucalyptus globulus Essential Oils Against Antibiotic-Resistant Escherichia coli and Mammaliicoccus sciuri from Diseased Animals in Tunisia. Current Microbiology, 82(14).
DOI: 10.1007/s00284-024-03981-6

2010. One-step microwave-assisted asymmetric cyclisation/hydrogenation of citronellal to menthols using supported nanoparticles on mesoporous materials. Organic & Biomolecular Chemistry, 8(13).
DOI: 10.1039/c003600e