Registration Dossier

Administrative data

Link to relevant study record(s)

Description of key information

No bioaccumulation potential expected based on several studies on cinnamaldehyde and cinnamyl derivatives. Studies indicate that cinnamyl derivatives can be anticipated to be rapidly absorbed, metabolized, and excreted, mainly in the urine, within 24 h.

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential
Absorption rate - oral (%):
85
Absorption rate - dermal (%):
85
Absorption rate - inhalation (%):
100

Additional information

Alpha methyl-cinnamaldehyde is a cinnamyl derivative and as such has been extensively researched. Cinnamyl alcohol and related substances have been examined by the US FDA as part of the Food additives series research. The Committee evaluated a group of flavouring agents that included cinnamyl alcohol, cinnamaldehyde, cinnamic acid, and 52 structurally related substances. The evaluations were conducted according to the Procedure for the Safety Assessment of Flavouring Agents.

 

The position and size of the substituent play a role in the metabolism of cinnamyl derivatives. Those containing alpha-methyl substituents (e.g. alpha-methylcinnamaldehyde) are extensively metabolized via beta-oxidation and cleavage to yield mainly the corresponding hippuric acid derivative. A benzoic acid metabolite was isolated from the urine of dogs given either alpha-methylcinnamic acid or alpha-methylphenylpropionic acid (Kay & Raper, 1924). Larger substituents located at the alpha- or beta-position inhibited beta-oxidation to some extent (Deuel, 1957; Kassahun et al., 1991), in which case there may be direct conjugation of the carboxylic acid with glucuronic acid, followed by excretion. While alpha-methylcinnamic acid undergoes oxidation to benzoic acid, alpha-ethyl- and alpha-propylcinnamic acids are excreted unchanged (Carter, 1941). alpha-Ethylcinnamic alcohol and alpha-ethylcinnamaldehyde administered orally to rabbits resulted in urinary excretion of alpha-ethylcinnamic acid and of small amounts of benzoic acid (Fischer & Bielig, 1940). These observations suggest that alpha-methylcinnamaldehyde undergoes oxidation to benzoic acid, while higher homologues are excreted primarily unchanged or as the conjugated form of the cinnamic acid derivative.

In 5 reliable good quality studies (Nutley, 1990), (Sapienza et al., 1993), (Peters & Caldwell, 1994), (Caldwell & Nutley, 1986), (Nutley et al., 1994) it was showed that cinnamaldehyde, cinnamyl alcohol and cinnamic acid are all excreted via urine and faeces at 85 -98% within 24h and 90 -100% with 72h of oral ingestion.

 

Studies therefore indicate that cinnamyl derivatives such as alpha methylcinnamaldehyde can be anticipated to be rapidly absorbed, metabolized, and excreted, mainly in the urine, within 24h and totally excreted with 72h. There is therefore no bioaccumulation potential.