Phenethyl acetate

Endpoint summary

Description of key information

Assessment of hydrolysis of flavouring esters by artificial gastric preparations and by fresh rat tissues.

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Absorption rate - oral (%):

90

Absorption rate - dermal (%):

33

Absorption rate - inhalation (%):

100

Additional information

The results of an in vitro study show relatively rapid hydrolysis of phenylethyl acetate by artificial gastro-intestinal juices and by liver and intestinal tissues and confirm the indications of rapid metabolic detoxification in the liver following repeat exposure and also the lack of bioaccummulation potential.

In a metabolism study used to provide read across data, benzyl acetate was absorbed from the gastrointestinal tract of rats and mice. Approximately 90% of the administered dose was recovered as various metabolites in the urine within 24 hr. The primary metabolite was hippuric acid, with minor amounts of mercapturic acid, and one or more unidentified metabolites. The capacity for absorption, metabolism, and disposition was unaffected by the amount or number of doses administered. In a chemical disposition study conducted by the NTP, male Fischer 344 rats and male B6C3F1 mice were shown to efficiently absorb and rapidly metabolize and excrete orally administered benzyl acetate. The doses used in this study were 5, 50, or 500 mg/ kg for rats and 10, 100, or 1000 mg/ kg for mice in single-dose corn oil gavage administrations and 500 mg/ kg for rats and 1,000 mg/ kg for mice daily five times per week for two weeks, also administered by gavage in corn oil. Most (90%) of the benzyl acetate-derived radioactivity was recovered in the urine and none was detected in the liver, blood, muscle, adipose tissue, skin, lung, kidney, or stomach of treated rats or mice. The major metabolite isolated in the urine was hippuric acid (94.6%-99.3% of the dose). Other metabolites found were mercapturic acid and benzyl alcohol. Benzyl acetate was not detected in the urine of treated animals. Neither the size of the dose nor the frequency of dosing had any effect on the absorption, metabolism, or excretion of this compound. There was no evidence to indicate any saturation of this metabolizing capacity in either species over the range of doses studied Oral absorption of benzyl acetate was approximately 90% based on urinary recovery of parent and metabolites. Dermal absorption was not quantified but was indicated to be considerably lower than oral absorption with marked losses due to volatilisation from appliaction sites and retention of unabsorbed dose on the dermal surface. An estimate of maximal dermal absorption was calculated and 33% dermal absorption is unlikely to be exceeded and may represent a combination of dermal penetration and unintended oral ingestion