Ethyl acetate

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

Effects on sperm: NOAEL >5.49mg/L, NOAEL >22mg/L

Reproductive toxicity( 2 generation study read across from ethanol after correction for molecular weight): NOAEL=26.4, 39.6g/kgbw/day. (Note, this is the prediction of the effect of the ethanol produced by hydrolysis. At such doses, the acidosis produced by the acetic acid released is likely to cause severe disturbance to homeostatis.)

Effect on fertility: via oral route

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

26 400 mg/kg bw/day

Species:

mouse

Effect on fertility: via inhalation route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

22 000 mg/m³

Species:

rat

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

A recent inhalation toxicity study conducted according to US EPA test guidelines in the Sprague-Dawley rat examined sperm parameters in male rats exposed over 94 days to ethyl acetate concentrations ranging from 350 to 1500 ppm (approx. 1.28 to 5.49 mg/L). There were no exposure-related changes in the number or concentration of spermatids in the testes, the number or concentration of sperm in the epididymides, sperm motility, or sperm morphology. Another less well reported study showed that subchronic inhalation exposures of concentrations as high as 6000 ppm (approx. 22.0 mg/L) ethyl acetate did not affect sperm counts, motility, or sperm concentration in Wistar rats. Further experiments in the same study did show that 5 minute acute exposures of around 16,000 ppm (approx. 58.6 mg/L) given twice daily for 7 days adversely affected plasma testosterone levels and spermatozoa counts; however, this concentration is close to the LD50 and the exposure time was sufficient to induce anaesthesia.

The rapid in vivo hydrolysis of ethyl acetate to ethanol allows data from the latter to be used as a surrogate to predict the toxicity of ethyl acetate to systemic end point such as fertility. A full justification for such a read across is attached as a report in chapter 13. A two-generational study investigated the effects of 5%, 10% and 15% ethanol in drinking water in reproduction and fertility. Male and female CD-1 mice were continuously treated for 1 week prior to mating and for a 14 week breeding period followed by a 21 day holding period when they were separated and housed individually. The F1 offspring of the 15% ethanol pairs had fewer live pups per litter but ethanol treatment had no effect on the proportion of breeding pairs producing at least 1 litter during the continuous breeding phase or the number of litters per pair. The F1 offspring from the 15% group had decreased bodyweight at weaning and mating, and a decreased weight of testis, epididymides and seminal vesicles which was no longer evident when these were adjusted for body weight. There was also a significantly decreased percentage motile sperm but no changes in sperm concentration, and percentage of abnormal sperm or tailless sperm. When reproductive performance of F1 control and 15% ethanol-treated breeding pairs was assessed at 74 days of age, there was no significant difference in mating and fertility between the groups. However, adjusted live pup weight for the ethanol group was significantly reduced compared to controls which was likely due to generalized maternal toxicity. The lowest NOAEL seen in this study 13800mg/kg/day ethanol for the F1 generation, which is equivalent to a dose of 26,400mg/kg/day ethyl acetate.

A single generation study is also available for ethanol by the inhalation route. Male Sprague-Dawley rats were exposed 7 hours per day for six weeks to 10,000 or 16,000ppm ethanol by inhalation and then mated with untreated female rats. Pregnant females received the same experimental treatment from day 1 -19 of gestation and were allowed to deliver their offspring. Treatment with ethanol did not affect the weight gain of parental animals. Incidence of fertility did not differ from controls and no group differences were found for litter size, number of dead pups, or length of pregnancy. Offspring survival and weight gain was also not affected by ethanol treatment. The direct rapid in vivo hydroylsis of ethyl acetate to ethanol allows the use of this study for ethyl acetate hazard assessment. The NOAEL from this study was 16000ppm.

Overall, the evidence suggests that the potential for ethyl acetate to cause fertility effects is low. A two generation study on the surrogate substance shows no effects with oral doses up to 13800mg/kg/day for ethanol (equivalent to 26400mg/kg/day ethyl acetate). By inhalation, ethyl acetate itself produced no effects at exposures of 6000ppm (22mg/l). Effects were reported following acute exposures to 16000ppm ethyl acetate. However, since this exposure is close to the LD50 and produced anaesthesia, this may not be a specific toxicity, a conclusion supported by the results from exposure to the surrogate substance ethanol which as the same equivalent concentration produced no adverse effects on fertility over prolonged exposure periods.

Short description of key information:
Ethyl acetate: No effect seen at 6000ppm (22000mg/m3) inhalation, maximum dose tested
Ethanol surrogate substance: No effects seen at 13800mg/kg in a 2 generation study, equivalent to NOAEL of 26400mg/kg/day ethyl acetate

Effects on developmental toxicity

Description of key information

Data for ethanol (surrogate):

NOAEC (inhalation, rat) maternal toxicity 16000ppm, teratogenicity >20000ppm

NOAEL (oral diet, mouse) maternal toxicity ~13.7, <12, 16 g/kg; teratogenicity 13.7, <12, 16g/kg respectively

NOAEL (oral, gavage, mouse): maternal toxicity 2.2g/kg, embryotoxicity >3.6g/kg, teratogenicity >6400g/kg

Effect on developmental toxicity: via inhalation route

Dose descriptor:

NOAEC

73 300 mg/m³

Additional information

There are no developmental toxicity studies available for ethyl acetate.  However, the rapid in vivo hydrolysis of ethyl acetate to ethanol allows data from the latter to be used as a surrogate to predict the toxicity of ethyl acetate to systemic end point such as fertility.  A full justification for such a read across is given in the report attached to chapter 13 of this dossier. Data for ethanol is described below:

Pregnant female rats were exposed to ethanol by inhalation at concentrations of 10000, 16000, or 20000ppm in a chamber for 7 hours per day on gestation days 1 -19. On day 20 the animals were euthanized and their fetuses examined. There was no definite increase in malformations at any level of ethanol exposure, although the incidence in the 20000ppm group was of borderline significance. There was clear maternal toxicity evident at the highest dose (narcosis, food intake reduction).  A NOAEL  for maternal toxicity of 16,000ppm was established (30,400mg/m3 ethanol, 58,6000mg/m3 ethyl acetate equivalent theoretical concentration) and a NOAEL  for teratogenicity of 20,000ppm (38,000mg/m3 ethanol, 73,300mg/m3 ethyl acetate equivalent theoretical concentration) was established.

Pregnant female mice were exposed to ethanol at 2200, 3600, 5000, 6400 and 7800 mg/kg/day by gavage from day 8 to 14 of gestation. Dams were sacrificed on day 18 and the content of the uterus and litters examined. Maternal mice treated at concentrations of 3600mg/kg ethanol and higher were lethargic and showed staggered gait and/or laboured breathing. Lethality in maternal animals increased dose dependently from 3600 mg/kg up to the highest dose group resulting in the death of all animals. At 5000 mg/kg, resorption of litters were increased and live foetuses/litters were decreased. This was not apparent in the one litter at 6400 mg/kg. No other fetal effects were seen.  This study determined a NOAEL of 3600mg/kg ethanol (equivalent to 6900mg/kg for ethyl acetate) for embryotoxicity and 2200mg/kg (equivalent to 4200mg/kg for ethyl acetate) for maternal toxicity.  No teratogenic effects were seen even at the highest dose tested.

Pregnant mice were fed a liquid diet containing 17%, 25%, or 30% ethanol-derived calories from day 4 to day 9 of gestation. Dams were sacrificed on day 18 of gestation. Ethanol treatment in dams did not induce any increase in mortality or change in weight gain with respect to controls. The incidence of fetal resoprtions and congenital malformations increased in a dose-related manner with significant effects in the groups treated with 25% and 30% ethanol-derived calorie diets, but no significant adverse effects were seen in the low dose group (estimated daily dose ~13-14g/day).

Female CBA and CH3 mice were exposed to liquid ethanol diet providing between 15%, and 25% ethanol derived calories for a period of at least 30 days before mating untreated males, and throughout gestation. Females were killed on day 18 of gestation and offspring examined for skeletal and soft tissue abnormalities. The CBA mice were more sensitive: at 15% and higher doses an increase in resorptions and significant number of abnormalities were noted.  However, the high doses used in this study and the fact that no NOAEL was established makes it of limited use in predicting the effects from non-oral consumption of ethanol.

Pregnant female New Zealand rabbits were exposed to 15% v/v ethanol in drinking water from day 6 through 18 of gestation. Animals were sacrificed on day 29 of gestation and their litters examined for resorption, number, vitality, weight, size, sex, cleft palate and external alterations of fetuses. Fetuses and heads were sectioned for analysis. There was an increase in resorptions, primarily due to the complete resorption of two litters in the ethanol group which was attributed to the severe reduction of water intake and marked loss of weight observed in this group. Fetal body measurements and the number of malformed fetuses were comparable between the control and experimental litters. The estimated dose of 4.1kg/day does not appear to cause developmental toxicity in rabbits.

There are studies that describe the results from screening assays using ethyl acetate in the chicken egg hatching assay.  These provide conflicting results, with the more recent of the two providing a negative outcome.  As these are non-standard assays, no significant weighting is given to the results and they are considered unreliable to predict the developmental toxicity in mammals.

The blood ethanol concentrations required to cause adverse developmental consequences, known as 'foetal alcohol syndrome' in humans, have been found to be in the range commonly found in alcoholics (150-200 mg/100 ml) and higher (350-800 mg/100 ml). Adverse effects similar to those reported for humans have been induced in rats by large intraperitoneal or gavage doses of ethanol. However, inhalation exposure of up to 20,000 ppm ethanol did not cause fertility, developmental or neurotoxic effects. Blood ethanol concentrations following the 0, 10,000, 16,000 and 20,000 ppm ethanol inhalation exposures were 0, 3, 50 and 180 mg/100 ml respectively.

Justification for classification or non-classification

There is no evidence from the data that ethyl acetate causes specific effects on fertility or cause developmental toxicity sufficient to warrant classification.