Canthoxal aka. Anisyl Propanal Aroma Chemical
CAS# 5462-06-6

Canthoxal (CAS number: 5462-06-6) is a commercially significant synthetic aroma chemical belonging to the class of monocyclic aromatic aldehydes. In the industry, this product is also known by various other names such as para-anisyl propanal, Fennaldehyde, Foliaver, and its official INCI designation, Methoxyhydratropaldehyde. Although some databases may incorrectly state that it is derived from natural sources, chemical literature confirms that Canthoxal is a fully synthetic molecule and has never been found in nature. At room temperature, Canthoxal exists as a clear, mobile, colorless to pale yellow liquid that is highly soluble in ethanol and other organic solvents.

Canthoxal is highly regarded by perfumers for its sweet, anisic, herbal, and floral odor profile. Upon smelling, this compound delivers characteristic notes of licorice, basil, fennel, and anise, softened by a watery/ozonic freshness and a light fruity nuance like raspberry. In fragrance formulations, Canthoxal acts as a top-to-heart note with a strong substantivity of over 48 hours on a smelling strip. This ingredient particularly shines when used to create juicy fruit accords, floral notes such as lily-of-the-valley (muguet) and mimosa, or as a foundation for oriental perfumes.

Thanks to its alpha-methyl group providing steric hindrance, Canthoxal exhibits better resistance to oxidation compared to simple aromatic aldehydes, giving it excellent stability. This product is highly compatible and performs well in a wide range of applications, from fine fragrances to personal care and household products such as soap bars, fabric conditioners, body washes, shampoos, and antiperspirant deodorants containing acidic aluminum salts. However, it is important to limit the use of Canthoxal in chlorine bleach or dry powder detergents due to the risk of degradation and oxidation. Additionally, Canthoxal is frequently reacted with Methyl Anthranilate to form "Schiff bases" (such as Canthoxalia) in the form of a highly viscous paste, which provides extremely long-lasting orange blossom and powdery notes.

Regarding safety, Canthoxal has low acute toxicity and is readily biodegradable (achieving 81% biodegradation within 28 days), making it an environmentally friendly choice. Although it is classified as a skin sensitizer at high concentrations, its regulatory limits have been significantly relaxed recently. Based on the 51st Amendment of the International Fragrance Association (IFRA), the maximum acceptable concentration of Canthoxal in fine fragrances (Category 4) has been increased from 0.82% to 2.5%. This provides greater creative freedom for perfumers who want to incorporate the fresh and clean notes of Canthoxal into modern compositions.