A 90-day toxicity study of phenylethyl alcohol in the rat

RIFM fragrance ingredient safety assessment, phenylethyl anthranilate, CAS Registry Number 133-18-6

The existing information supports the use of this material as described in this safety assessment. Phenylethyl anthranilate was evaluated for genotoxicity, repeated dose toxicity, developmental and reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data from phenylethyl anthranilate and the read-across analog cinnamyl anthranilate (CAS # 87-29-6) show that phenylethyl anthranilate is not expected to be genotoxic. The skin sensitization endpoint was completed using the DST for non-reactive materials (900 μg/cm²); exposure is below the DST. The reproductive and local respiratory toxicity endpoints were evaluated using the TTC for a Cramer Class II material, and the exposure to phenylethyl anthranilate is below the TTC (0.009 mg/kg/day and 0.47 mg/day, respectively). Data on read-across analogs phenethyl alcohol (CAS # 60-12-8) and anthranilic acid (CAS # 118-92-3) provide a calculated MOE >100 for the repeated dose and developmental toxicity endpoints. The phototoxicity/photoallergenicity endpoints were evaluated based on UV spectra; phenylethyl anthranilate is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; phenylethyl anthranilate was found not to be PBT as per the IFRA Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., PEC/PNEC), are <1.

4 Final Report on the Safety Assessment of Phenethyl Alcohol

Phenethyl Alcohol (PEA) is an aromatic alcohol that is used as a fragrance and an antimicrobial preservative in cosmetic formulations. PEA is metabolized to phenyl-acetic acid in mammals. In humans, it is excreted in urine as the conjugate phenylacetylglutamine.

The acute oral LD50s of PEA to rats ranged from 2.5 to 3.1 ml/kg, and for mice and guinea pigs was 0.8 to 1.5 g/kg and 0.4 to 0.8 g/kg, respectively. The dermal LD50s for rabbits and guinea pigs were 0.8 g/kg and 5 g/kg, respectively. PEA was slightly to moderately irritating to the skin of rabbits and guinea pigs and was not a guinea pig sensitizer. PEA, in concentrations of 1 % or greater, was irritating to the eyes of rabbits. PEA was neither an irritant nor a sensitizer in human studies.

PEA was not mutagenic in the Ames test or in an Escherichia coli DNA-polymerase-deficient assay system. PEA did inhibit the repair of radiation-induced breaks in the DNA of E. coli. PEA did not increase the number of sister chromatid exchanges in human lymphocytes.

Maternal exposure to PEA, microencapsulated in the feed, at concentrations of 1000, 3000, and 10,000 ppm had no effect on embryo-fetal loss, or embryo-fetal development and morphology. There was an increased incidence of incomplete ossification in the 10,000 ppm PEA group litters. Doses of 0.14, 0.43, and 1.40 ml/kg of PEA were applied to the skin of pregnant rats. Maternal toxicity was marked at the highest dose, Morphological abnormalities in fetuses in the 1.40 ml/kg PEA group were observed. The number of fetuses with moderate degrees of reduced ossification and with cervical rib(s) was significantly greater in the 0.43 ml/kg PEA group than in the controls. The incidence of structural changes was slightly greater in 0.14 ml/kg PEA-treated rats than in control rats. Dermal doses of 0.07,0.14,0.28,0.43, and 0.70 ml/kg/day PEA to pregnant rats significantly increased cervical ribs in the 0.70 ml/kg/day group litters.

The highest no observed adverse effect level (NOAEL) was 0.43 ml/kg/day for cervical rib malformation (teratogenic effect). The dermal applied teratogenicity NOAEL of 0.43 ml/kg/day was used to estimate a safe use level of 1.0% PEA in cosmetic products.

Oral and Dermal Developmental Toxicity Studies of Phenylethyl Alcohol in Rats

Phenylethyl alcohol (PEA) was tested for developmental toxicity. Pregnant rats were fed 0, 83, 266, or 799 mg/kg/d PEA on gestation days (GDs) 6 to 15; only minimal, nonsignificant effects were observed. In dermal studies, PEA (neat) was applied to the skin on GDs 6 to 15 at dosages of 0, 140, 430, or 1400 mg/kg/d and at 0, 70, 140, 280, 430, or 700 mg/kg/d in a corroborative study. Observations included maternal and embryo-fetal toxicity/abnormalities at 1400 mg/kg/d, increased incidences of rudimentary cervical ribs at ≥430 mg/kg/d, and reduced fetal body weights at ≥140 mg/kg/d. Dermal maternal and developmental no-observed-adverse-effect levels are 70 mg/kg/d, based on dermal irritation and reductions (nonsignificant) in fetal body weights. Human exposure from fragrances is 0.02 mg/kg/d, resulting in a margin of safety >2600, when marked differences in dermal absorption between rats and humans are considered. Under normal fragrance use conditions, PEA is not a developmental toxicity hazard for humans.

Fragrance material review on linalyl phenylacetate

A toxicologic and dermatologic review of linalyl phenylacetate when used as a fragrance ingredient is presented.

Antibacterial activity of phenethyl alcohol and resulting membrane alterations

The antibacterial activity of phenethyl alcohol (PEA) towards Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus and Enterococcus faecium) was investigated. This activity was expressed as IC (inhibitory concentration) and BC (bactericidal concentration). PEA was bactericidal in the concentration range of 90 to 180 mM, these concentrations being 4- to 5-fold higher than the corresponding IC. The mechanism of action of PEA upon the cell membrane of bacteria was also studied. Morphological examination with a transmission electron microscope showed that Gram-negative cell envelopes were permeabilized; for Gram-positive bacteria, the plasmic membrane in S. aureus was solubilized, whereas lesser changes were observed in E. faecium. At lethal concentrations, PEA also induced a rapid and total leakage of K+ ions from the four strains studied. Despite the correlation between alterations in the structural integrity of the cytoplasmic membrane in Gram-negative cells and the loss of cell viability, it cannot be inferred that membrane damage is the only cause of the lethal effect.

Effects of various exposure levels of 2-phenylethanol on fetal development and survival in Long-Evans rats

Phenylethanol was given at different levels (432, 43, or 4.3 mg/kg) by gavage to pregnant Long-Evans rats during the "critical period" of organogenesis. Examination of offspring revealed adverse reproductive and teratogenic effects in a dose-related manner. Intrauterine growth retardation occurred at levels of 432 and 4.3 mg/kg. Embryolethality was 18% at 43 mg/kg and 10% at 4.3 mg/kg. Malformations occurred in the following sequence: 100% at 432 mg/kg; 93% at 43 mg/kg, and 50% at 4.3 mg/kg. Noteworthy dose-related teratogenic effects of phenylethanol in offspring manifested themselves in increased incidences of malformed eyes, neural-tube defects, hydronephrosis, and limb defects.