2-phenoxyethanol

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

In a multi-generation study, fertility was minimally decreased at a dose that caused neonatal toxicity. The NOAEL for parental and neonatal toxicity was 375 mg 2-phenoxyethanol/kg bw/day.

Link to relevant study records

Reference

Endpoint:

two-generation reproductive toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13 Jul 1983 - 28 Mar 1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: Reproductive Assessment by Continuous Breeding (RACB); protocol devised by the NTP

Version / remarks:

The RACB protocol does not possess a defined pre-mating exposure. Especially potential effects on male fertility are less likely to become manifest than in the OECD 416 protocol. This deficiency is in part compensated by the cross-breeding (Task 3) which demonstrated the absence of effects on male fertility after a one-week pre-mating exposure.

Deviations:

no

GLP compliance:

yes

Remarks:

Research Triangle Institute

Limit test:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): Ethylene glycol monophenyl ether (EGPE)
- Physical state:
- Analytical purity: 94-95 % (according to Heindel, J. J. et al., 1990)
- Impurities (identity and concentrations): 6 impurities estimated at a total concentration of 5.5-6.0 % were reported, with none of them exceeding 1.0 %
- Lot/batch No.: C093082 / 01
- Stability under test conditions: Doses were freshly prepared on a weekly basis. Analysis of EGPE in the feed showed a 5.0 % loss in the course of one week.
- Storage condition of test material: stored tightly sealed at 25 °C

Species:

mouse

Strain:

CD-1

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding laboratories Inc., NY
- Age at study initiation: 11 weeks of age at the start of the continuous breeding
- Diet (e.g. ad libitum)
- Water (ad libitum)
- Housing: group housed in solid bottom polypropylene or polycarbonate cages
- Acclimation period: 5 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21±2
- Humidity (%): monitored by electronic hygrothermographs
- Air changes (per hr): 12-14 times per hour
- Photoperiod (hrs dark / hrs light): 10 /14

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

DIET PREPARATION
Each dose of ethylene glycol monophenyl ether (EGPhE) was independently blended into a small amount of ground feed. This mixture was added to a preweighed portion of feed and mixed in a blender for 15 min. Dosed feed was found to lose about 5% of test material over 7 days, therefore, dosed feed was prepared fresh weekly. Concentrations were found to be within 96-105 % of target levels.

Details on mating procedure:

Premating exposure period
Male : 7 days
Female : 7 days
Continuous breeding
Deviation from OECD 416: Differing from the defined pre-mating treatment period laid out in OECD 416, the RACB protocol involves a 98-day continuous breeding period. Unlike the OECD protocol, copulation takes place among animals without appreciable pre-treatment.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The analysis of aliquots of 6 representative samples over the study period revealed EGPE concentrations in the preparations which were within 96-105 % of the expected values.

Duration of treatment / exposure:

7 days prior to and during a 98-day cohabitation period

Frequency of treatment:

Oral feed:
in food, offered ad libitum

Details on study schedule:

Task 1: 14-day dose setting study (range finder)
Task 2: Both sexes were dosed for 7 days prior to and during a 98-day cohabitation period
Task 3: Pairs (P) are mated for 7 days or until a copulatory plug was detected. Treatment was discontinued for all animals during this week then reinstated at the appropriate dose until necropsy (3 weeks after the 7-day cross-over period).
Task 4: the last litter from task 2 is nursed, weaned, reared to sexual maturity while housed by sex two or three per cage and exposed to the same concentration of the test materials as their parents. At 74 ± 10 days of age, males and females from different litters within the same treatment group are cohabited for 7 days or until copulatory plug was seen and then housed individually until delivery. At the end of Task 4, the F1 mice were sacrificed and necropsied.

Dose / conc.:

0.25 other: % (nominal)

Remarks:

main study (concentrations selected on the basis of range finder)

Dose / conc.:

1.25 other: % (nominal)

Remarks:

main study (concentrations selected on the basis of range finder)

Dose / conc.:

2.5 other: % (nominal)

Remarks:

main study (concentrations selected on the basis of range finder)

Dose / conc.:

1 other: % (nominal)

Remarks:

range finder

Dose / conc.:

2.5 other: % (nominal)

Remarks:

range finder

Dose / conc.:

5 other: % (nominal)

Remarks:

range finder

Dose / conc.:

10 other: % (nominal)

Remarks:

range finder

No. of animals per sex per dose:

Task 1: 8 animals per sex per group
Task 2: 40 breeding pairs for control, 20 breeding pairs per treatment group
Task 3: 3 groups of 20 pairs
Task 4: 19 pairs/group

Control animals:

yes, plain diet

Details on study design:

Animals were 6 weeks old upon receipt and were quarantined for 2-5 weeks. During this period, 2 females and 2 males were killed and their sera was analyzed for 11 viruses. All tests were negative. They were randomly assigned to groups by body weight.

Parental animals: Observations and examinations:

Food consumption, parental body weights (time not specified), mortality and clinical signs of toxicity of parents were evaluated.

Oestrous cyclicity (parental animals):

examined

Sperm parameters (parental animals):

testes weight, epididymes weight, enumeration of cauda epididymidis sperm reserve, sperm motility, sperm morphology

Litter observations:

number and sex of pups, live births, live pup weight

Postmortem examinations (parental animals):

Organ weights:
Uterus, ovaries, testes, epididymes (total and cauda), prostate, seminal vesicles, brain, liver, pituitary
Histopathology:
Vagina
uterus
ovaries
oviduct
testis
epididymes
seminal vesicle
prostate
coagulating gland

Postmortem examinations (offspring):

Organ weights:
Uterus, ovaries, testes, epididymes (total and cauda), prostate, seminal vesicles, brain, liver, pituitary
Histopathology:
Vagina
uterus
ovaries
oviduct
testis
epididymes
seminal vesicle
prostate
coagulating gland

Statistics:

The Cochran-Armitage test was used to evaluate any dose-related trends in fertility. A chi square test was used to analyze data from Task 3. Pairwise comparisons between the control and dosed groups were made with the Fisher's exact test. The number of litters and the number of live pups per litter were computed on a fertile pair basis and treatment group means were determined. Dose groups means for these variables, the sex ratio and the proportion of live pups were analyzed using a Kruskal-Wallis test. Ordered differences were tested for by Jonckheere's test.
The Wilcoxon-Mann-Whitney U test was used to make intergroup pairwise comparisons.
An analysis of covariance was performed to correct for the potential effect of the number of pups per litter on the average pup weight. The covariate used was average litter size, including live and dead pups. Least squares estimated of dose group means, adjusted for litter size, were computed and tested for overall equality using an F test and pairwise equality was tested using a t test. Average organ weights adjusted for body weight were tested for equality an analysis of covariance. Absolute organ weights were analyzed by the Kruskal-Wallis and Wilcoxon-Mann-Whitney U tests. Dose-related trends were tested for by Jonckheere's test.

Analyses were performed on data for males and females separately and with both sexes combined. The criterion for significance was p<0.05.

Clinical signs:

effects observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

not specified

Other effects:

no effects observed

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

effects observed, treatment-related

Task 1: During the 14-days exposure 2 males and 3 females exhibited dehydration in the 7.5 % dose group, one of the females in the 7.5 % dose group died before conclusion of task 1. Three of 7 males and 2 of 4 females in the 10 % group that exhibited dehydration and piloerection during the first week died during the second week. By the Chi-Square and Fischer’s Exact Tests, the percent lethality was significantly elevated in the 10 % dose group. The LD10 and LD50 values were determined to be 8.2 % and 11 %, respectively (Probit Analysis). In addition the % weight gain for the sexes combined was significantly decreased (p = 0.05) in the 5 % group relative to the lower dose and control group. Based on these results dietary levels of, 0, 0.25, 1.25and 2.5 % test substance were selected for Task 2.

Task 2: Continuous exposure of CD-1 mice to these dietary levels had no effect on the number of pairs able to produce at least one litter. No effect on the sex (males/total) of pups born alive was observed. In contrast, exposure to 2.5 % in the feed tended to reduce the number of litters delivered perpair and significantly reduced the average litter size and proportion of pups born alive compared to the control and the 0.25 % and 1.25 % groups. Further there was a significant (p < 0.01) dose-related decrease in live pup weight during continuous exposure of F0 breeding pairs as revealed by Jonckheere’s Test. Live pup weight adjusted for total pups per litter showed a similar dose-related pattern.

Task 3: The proportion of detected matings, fertile pairs pups born alive, sex of pups born alive (males/total) or number of pups/litter did not differ significantly across the three combinations of breeding pairs, absolute live pup weight (sexes combined) adjust for total pups / litter was significantly (p>0.01) decreased for the control males x 2.5 % test substance females versus the control females x control males and 2.5 % test substance males x control females. The results implied that 2-phenoxyethanol was selectively fetotoxic in the F0 females. The control and 2.5 % test substance exposed F0 mice were necropsied three weeks after the 7-day crossover mating period. No significant effects were observed in % motile sperm, sperm concentration, or % abnormal sperm in cauda epididymidis between male control mice and males of the 2.5 % test group. Also no significant effects were observed with respect to brain, pituitary, left testis/epididymes, right testis and prostate weights. However, body weight and seminal vesicle weight were significantly reduced (p > 0.05) and liver weight significantly increased (p > 0.01). When adjusted to body weight the differences in seminal vesicle weight was no longer statistically significant different from control. Liver weight was also significantly increased in female mice fed 2.5 % test substance in the diet compared to control. Body, brain, pituitary, ovary/oviduct and uterine weights did not differ significantly when compared to control.

EGPE reduced reproductive performance at doses that increased liver weights in treated F0 mice.

Dose descriptor:

LOAEL

Remarks:

general effects

Effect level:

ca. 3 700 mg/kg bw/day

Sex:

male

Basis for effect level:

body weight and weight gain

organ weights and organ / body weight ratios

Dose descriptor:

LOAEL

Remarks:

reproductive effects

Effect level:

> 3 700 mg/kg bw/day

Sex:

male

Basis for effect level:

other: based on the absence of effects on male fertility

Dose descriptor:

LOAEL

Remarks:

general effects

Effect level:

ca. 3 700 mg/kg bw/day

Sex:

female

Basis for effect level:

organ weights and organ / body weight ratios

Dose descriptor:

LOAEL

Remarks:

reproductive effects

Effect level:

ca. 1 875 mg/kg bw/day

Sex:

female

Basis for effect level:

body weight and weight gain

Dose descriptor:

NOAEL

Remarks:

general effects

Effect level:

ca. 1 875 mg/kg bw/day

Sex:

male

Basis for effect level:

other: no adverse effects

Dose descriptor:

NOAEL

Remarks:

reproductive effects

Effect level:

ca. 3 700 mg/kg bw/day

Sex:

male

Basis for effect level:

other: no adverse effects

Dose descriptor:

NOAEL

Remarks:

general effects

Effect level:

ca. 1 875 mg/kg bw/day

Sex:

female

Basis for effect level:

other: no adverse effects

Dose descriptor:

NOAEL

Remarks:

reproductive effects

Effect level:

ca. 1 875 mg/kg bw/day

Sex:

female

Basis for effect level:

other: no adverse effects

Clinical signs:

no effects observed

Mortality / viability:

mortality observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Sexual maturation:

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

no effects observed

Histopathological findings:

not specified

Task 4: There was reduced body weight gain to weaning: the middle and high dose groups weighed 25 % and 58 % less than controls at weaning on postnatal day 21; on postnatal day 74, the weight differences were 11 % and 17 %, respectively. Mortality was also increased in the middle and high dose groups from weaning to mating postnatal day 74. This was most pronounced in the high dose group: of the 56 pups weaned in this group, only a total of 6 survived to mating at postnatal day 74. This provided too few animals for statistical analysis. At the mating of the second generation, there was no treatment-related effect on F2 pup number or sex ratio. F2 pup weight adjusted for litter size was reduced in the 1.25 % group by 7 %.
After the delivery of the F2 pups, the control and the 1.25 % group F1 mice were killed and necropsied. The 1.25 % mice weighed 13 % less than controls, their absolute testes weight was 16 % less, and relative seminal vesicles weight was 14 % less than control. The 1.25 % female test group weighed 7 % less than controls; there were no adjusted weight changes in the treated females. There were no treatment-related alterations in epididymal sperm concentration, motility, or morphology.

The test substance caused reduced body weight in neonates in Task 2, 3, and 4, and reduced post-natal survival in F1 animals that were raised to sexual maturity.

Dose descriptor:

LOAEL

Generation:

F1

Effect level:

ca. 1 875 mg/kg bw/day

Sex:

male

Basis for effect level:

body weight and weight gain

organ weights and organ / body weight ratios

Dose descriptor:

LOAEL

Generation:

F1

Effect level:

ca. 1 875 mg/kg bw/day

Sex:

female

Basis for effect level:

body weight and weight gain

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

ca. 375 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: no adverse effects

Dose descriptor:

NOAEL

Generation:

F2

Effect level:

ca. 375 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: no adverse effects

Reproductive effects observed:

not specified

Effect on fertility: via oral route

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

375 mg/kg bw/day

Study duration:

subchronic

Species:

mouse

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

A multi-generation reproduction study evaluating 2-phenoxyethanol according to the Reproductive Assessment by Continuous Breeding Protocol (NTP, 1984) was conducted by the National Toxicology Program and reported in a peer-reviewed journal (Heindel et al, 1990). In this study, male and female mice were given 2-phenoxyethanol in feed at dose levels of approximately 0, 375, 1875 or 3,700 mg/kg bw/day.

The oral feeding with 2-phenoxyethanol resulted in loss of body weights (-2%) of high-dose males compared to controls, while female body weights were unaffected. There were also no significant differences in feed consumption. Liver weights were increased at the highest-dose level. 2-Phenoxyethanol had no effect on fertility. However, the number of litters/pair, the litter size, proportion of pups born alive and pup body weights were decreased at the highest dose. The only effect observed at the mid-dose level consisted of an equivocal lower pup body weight. There were no effects on any of these parameters at the low-dose level. A crossover mating trial demonstrated no effects on mating or fertility, however, pup body weights of females given 3,700 mg/kg bw/day of the test substance were lower than the controls. In summary, fertility was minimally decreased at a dose that caused neonatal toxicity. Reproductive performance in the low- and mid-dose groups was unaffected. The NOAEL for parental and neonatal toxicity was 375 mg 2-phenoxyethanol/kg bw/day.

Effects on developmental toxicity

Description of key information

In a dermal rabbit and oral (gavage) rat teratogenicity study, no effects on the developing foetus were seen.

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27 Sep 2005 - 07 Oct 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.31 (Prenatal Developmental Toxicity Study)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.3700 (Prenatal Developmental Toxicity Study)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Landesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht; Experimental Toxicology and Ecology BASF Aktiengesellschaft

Limit test:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): 2-Phenoxyethanol
- Physical state: Liquid/colorless
- Analytical purity: >99.9 core peak-area %
- Lot/batch No.: 41183068E0
- Expiration date of the lot/batch: 23 Jul 2006
- Stability under test conditions: The stability of the test substance under storage
conditions over the test period was guaranteed by
the sponsor.
- Storage condition of test material: Room temperature, under N2 conditions, exclusion
of light

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Research Models and Services, Germany GmbH [former: Charles River Laboratories, Germany]
- Age at study initiation: 11 to 13 weeks
- Weight at study initiation: 144.9 – 185.3 g
- Housing: Rats were housed singly from day 0-20 p.c. in type DK III stainless steel wire mesh cages.
- Diet (ad libitum): Ground Kliba maintenance diet mouse/rat "GLP"
- Water (ad libitum): tap water
- Acclimation period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 30-70
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: 1st cohort From: 27 Sep 2005 To: 17 Oct 2005; 2nd cohort From: 28 Sep 2005 To: 18 Oct 2005

Route of administration:

oral: gavage

Vehicle:

water

Remarks:

and a few drops Tween 80

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The test substance emulsions were prepared at the beginning of the administration period and thereafter at intervals, which took into account the analytical results of the stability verification. For the preparation of the emulsions, appropriate amounts of the test substance were weighed into calibrated beakers and were topped up with tap water and a few drops Tween 80 (as emulsifier). Afterwards they were intensely mixed with a magnetic stirrer. A magnetic stirrer was used to keep the emulsions homogeneous during the procedure of dosing the animals.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analytical verifications of the stability of the test substance in demineralized water for a period of at least 96 hours at room temperature were carried out before the study was initiated (in a similar batch). Samples of the test substance emulsions were sent to the analytical laboratory twice during the study period (at the beginning and towards the end) for verification of the concentrations. The samples, which were taken for the first concentration control analyses at the beginning of the administration period, were also used to verify the homogeneity for the samples of the low and the high concentrations (100 and 1,000 mg/kg body weight/day). Three samples (one from the top, middle and bottom in each case) were taken for each of these concentrations from the beaker with a magnetic stirrer running.

Details on mating procedure:

The animals were paired by the breeder and supplied on day 0 post coitum (= detection of vaginal plug / sperm).

Duration of treatment / exposure:

gestation day 6-19 (post mating)

Frequency of treatment:

once daily

Duration of test:

28 days

Dose / conc.:

100 mg/kg bw/day (nominal)

Dose / conc.:

300 mg/kg bw/day (nominal)

Dose / conc.:

1 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

25

Control animals:

yes, concurrent vehicle

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily
Animals were checked from day 0 to 20 p.c. at least once daily for clinical symptoms whereas check for mortality was conducted twice a day on working days, and once a day during weekend or public holidays.

BODY WEIGHT: Yes
- Time schedule for examinations: Body weights were recorded on days 0, 1, 3, 6, 8, 10, 13, 15, 17, 19 and 20 post mating (p.c.).

FOOD CONSUMPTION was recorded on days 1, 3, 6, 8, 10, 13, 15, 17, 19 and 20 p.c..

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 20

The scope of examinations exceeded the respective test guideline requirements. It was enhanced by clinical pathology examinations (hematology and clinical chemistry). For this purpose, blood samples were collected from the retroorbital venus plexus at study termination.
Hematology
The following parameters were determined in blood:
• leukocytes
• erythrocytes
• hemoglobin
• hematocrit
• mean corpuscular volume
• mean corpuscular hemoglobin
• mean corpuscular hemoglobin concentration
• platelets
• differential blood count
• reticulocytes
• prothrombin time (Hepato Quick's test)

Clinical chemistry
An automatic analyzer was used to examine following clinical chemical parameters:
• alanine aminotransferase
• aspartate aminotransferase
• alkaline phosphatase
• γ-glutamyltransferase
• sodium
• potassium
• chloride
• inorganic phosphate
• calcium
• urea
• creatinine
• glucose
• total bilirubin
• total protein
• albumin
• globulins
• triglycerides
• cholesterol
• magnesium

Ovaries and uterine content:

At study termination and following blood samples collection, the animals were sacrificed. The sacrificed animals as well as the one animal of the 1,000mg/kg bw/day group that was prematurely killed because of moribund state were subjected to necropsy and gross pathology, and the ovaries and uterus were removed for following examination:

Gravid uterine weight (excepted for the prematurely sacrificed animal)
Number of corpora lutea
Number of implantations (implantation sites, live/dead implantations)
The conception rates, as well as the pre- and post-implantation losses, were calculated.

Fetal examinations:

Litter size, number of dead fetuses, fetal weight, sex ratio, external alterations. Furthermore, the viability of the fetuses and the condition of the placentae, the umbilical cords, the fetal membranes, and fluids were examined. Individual placental weights were recorded.

Following sacrifice, 50% of the fetuses were prepared for the purpose of skeletal examination.

The remaining half of the sacrificed fetuses was prepared for the purpose of visceral examination.

Statistics:

Simultaneous comparison of all dose groups with the control group using the DUNNETT-test (two-sided) for the hypothesis of equal means.
Pairwise comparison of each dose group with the control group using FISHER'S EXACT-test (one-sided) for the hypothesis of equal proportions.
Pairwise comparison of each dose group with the control group using the WILCOXON-test (one-sided) for the hypothesis of equal medians.
Non-parametric one-way analysis using KRUSKAL-WALLIS-test (two-sided). If the resulting p-value was equal or less than 0.05, a pair-wise comparison of each dose group with the control group was performed using Wilcoxon-test (two-sided) for the equal medians.

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Test group 3 (1,000 mg/kg b.w./day):
• one high dose female was sacrificed in moribund condition, preterminally, lateral position, unsteady gait, vaginal hemorrhage, salivation and respiratory sounds were observed
• all dams at least once showed unsteady gait (from day 6 p.c. onwards) and transient salivation (from day 8 p.c. onwards), although not all animals exhibited these findings on any one day, those findings persisted for a short time (up to 3.5 hours) after the dosing
• individual dams were found in lateral position shortly after treatment (5/25), had vaginal hemorrhage (2/25) and/or urine smeared fur (2/25) on several occasions during dosing
• mean food consumption was statistically significantly reduced (at maximum 10 % below control) on days 6 - 13 p.c., if calculated for the entire treatment period (days 6 - 19 p.c.), the food intake was about 6 % below control
• mean body weights were slightly, but statistically significantly below control on days 8 – 20 p.c., on day 20 p.c. mean body weight was about 4 % below control
• statistically significantly lower body weight gain was noted after initiation of treatment (days 6 - 8 p.c., about 44 % below control), average weight gain during entire treatment period (days 6 - 19 p.c.) was statistically significantly below control (about 12 %)
• net maternal body weight was about 4 % below control, net maternal body weight gain was about 14 % below control

No test substance-related adverse effects on dams in test group 1 (100 mg/kg bw/day) and test group 2 (300 mg/kg bw/day).

Dose descriptor:

LOAEL

Effect level:

ca. 1 000 mg/kg bw/day

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOAEL

Effect level:

ca. 300 mg/kg bw/day

Basis for effect level:

other: maternal toxicity

Dose descriptor:

LOAEL

Effect level:

> 1 000 mg/kg bw/day

Basis for effect level:

other: no adverse effects

Dose descriptor:

NOAEL

Effect level:

ca. 1 000 mg/kg bw/day

Basis for effect level:

other: no adverse effects

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
Gestational parameters:
At terminal sacrifice 22 - 25 females/group had implantation sites.
2-phenoxyethanol had no influence on gestational parameters up to and including the limit dose of 1,000 mg/kg bw/day.

Developmental toxicity:
2-phenoxyethanol induced no signs of developmental toxicity.

Fetal external, soft tissue and skeletal observations:
The external and skeletal malformations in one individual fetus from control and in 2 low dose group fetuses (0 and 100 mg/kg bw/day), which were related to the head/skull and sternebra, are considered to be spontaneous findings.
No soft tissue malformations were recorded at all. If all the different types of malformations are summarized, in total one out of 210 examined control fetuses [= 0.5 %] in one out of 25 litters [= 4.0 %], 2 out of 206 low dose fetuses [= 1.0 %] in 2 out of 25 litters [= 8.0 %], none of the 204 mid dose fetuses (from 23 litters) and none of the 180 high dose fetuses (from 22 litters) showed malformations.
The mean percentages of affected fetuses/litter with total malformations amounted to 0.4, 1.0, 0.0, and 0.0 % at 0, 100, 300 or 1,000 mg/kg bw/day respectively. These low, not dose-related incidences do not suggest any relationship to the test substance.
External variations did not occur in any of the fetuses in this study. Soft tissue variations, in the form of dilated renal pelvis or short innominate occurred in all test groups including the controls without any relation to dosing. The skeletal variations consisted primarily of small disturbances or transient delays of ossification. Most of the skeletal variations were equally distributed among the different test groups including controls, if normal biological variation is taken into account. All fetal and litter incidences for these variations and the corresponding mean percentages of affected fetuses/litter did not show a relation to dosing, were not considered to be of any toxicological relevance and/or can be found at a comparable frequency in the historical control data. If all variations are summarized, in total 119 of the 210 examined control fetuses [= 57 %] in all 25 litters [= 100 %], 107 of the 206examined low dose fetuses [= 52 %] in all 25 litters [= 100 %], 110 out of 204 mid dose fetuses [= 54 %] in all 23 litters [= 100 %] and 104 out of 180 high dose fetuses [= 58 %] in all 22 litters [= 100 %] showed variations. The mean percentages of affected fetuses/litter with total variations amounted to 57.2, 52.3, 54.0, and 58.1 % at 0; 100; 300 or 1,000 mg/kg bw/day, respectively. These overall incidences do not suggest a treatment-relationship, but reflect the usual biological variation inherent in the strain of rats used for this experiment. A spontaneous origin is assumed for the unclassified external and the unclassified cartilage observation, that were recorded for very few fetuses of test groups 0, 1, 2 and 3 (0; 100; 300 or 1,000 mg/kg bw/day). Distribution and type of these findings (i.e. blood coagulum around placenta, bipartite processus xiphoideus, notched cartilage between basisphenoid and basioccipital and notched manubrium) do not suggest any relation to treatment. Thus, the oral administration of phenoxyethanol to pregnant Wistar rats had no effect on development and morphology of offspring at any of the dose levels tested (100, 300 and 1,000 mg/kg bw/day).

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day

Sex:

not specified

Basis for effect level:

other: no signs of developmental toxicity

Abnormalities:

not specified

Developmental effects observed:

not specified

Hematology and serum enzyme examinations revealed no treatment-related changes. Clinical chemistry investigations showed decreased concentrations in total bilirubin, total protein, albumin and globulin as well as increased triglyceride values in the serum of the high dose animals (1,000 mg/kg bw/day). Similar effects on clinical chemistry parameters, with somewhat lower severity, were noted in the mid dose animals (300 mg/kg bw/day). All of these findings were rather related to adaptive metabolic changes, than indicative of particular organ toxicity. Although these effects were likely to be caused by the test material, they were not considered as adverse per se.

Reference 2

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

yes

Remarks:

test substance was applied dermal; gravid uterine weight was not determined

GLP compliance:

yes

Remarks:

Mammalian and Environmental Toxicology Research Laboratory

Limit test:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): 2-phenoxyethanol
- Analytical purity: 99.9 % active substance (GC)
- Lot/batch No.: #53 (C44172)
- Source: Nipa Laboratories, Ltd., UK

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Hazleton-Dutchland, Inc. (Denver)
- Weight at study initiation: 3.5-4.5 kg
- Housing: Animals were housed in wire-bottom cages.
- Diet (ad libitum): Certified Laboratory Rabbit Chow #5322, Ralston Purina Company, St. Louis, MO
- Water (ad libitum): municipal tap water
- Acclimation period: at least two weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22
- Humidity (%): 54-80
- Photoperiod (hrs dark / hrs light): 12

Route of administration:

dermal

Vehicle:

unchanged (no vehicle)

Analytical verification of doses or concentrations:

yes

Details on mating procedure:

artificial insemination according to Gibson et al., 1966

Duration of treatment / exposure:

days 6-18 of gestation

Frequency of treatment:

once daily

Duration of test:

28 days

Dose / conc.:

300 mg/kg bw/day (nominal)

Dose / conc.:

600 mg/kg bw/day (nominal)

Dose / conc.:

1 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

25

Control animals:

yes

Details on study design:

Control animals were treated with distilled water at a targeted volume of 0.91 ml/kg body weight. The targeted dose volume of undiluted 2-phenoxyethanol (specific gravity = 1.1) was 0.27, 0.55 and 0.91 ml/kg for the targeted dose levels. The highest dose of 1000 mg/kg/day was the maximum amount of liquid which could be applied to the clipped area on the animal´s back without excessive run off at the time of application or subsequent loss from absorption through he gauze liner into the cloth.
The methods of application and occlusion of the application site were similar to those developed by Quellette et al., 1983. A section (10x15 cm) on the back of each rabbit was clipped free of hair with electric clippers on day zero of gestation. On day 6 of gestation, an occlusive bandage of absorbent gauze, non-absorbent cotton and cloth held in place with adhesive tape was placed over the dosing area on the back. Rabbits remained in these bandages throughout the dosing period. The bandages were loosened in order to apply the test material each day and then retaped with adhesive tape. Bandages were replaced as needed during the treatment if they became loose or damaged due to the animal´s movement. On day 19 of gestation, the bandages were removed and the area of application wiped to remove any residue of test material.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: body weights were recorded daily throughout the treatment period (day 6 to 18 of gestation) and thereafter on days 19 and 28 of gestation.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 28

Animals were observed daily throughout the experimental period for indications of toxicity. Animals found dead or moribund were submitted to gross pathological examination. Statistical analysis of body weight and body weight gain were performed using data recorded on gestation days 6, 9, 12, 15, 19 and 28. In order to assess hematologic effects observed in dead and moribund animals, blood was collected from an ear vein from approximately 10 animals per dose group (0, 300 and 600 mg/kg b.w./day) on day 19 of gestation for the following measurements: packed cell volume (PCV), hemoglobin (HgB), erythrocyte count (RBC), total leukocyte count (WBC), red blood cell indices (MCV, MCM, MCHC), reticulocyte count, red cell osmotic fragility, WBC differential counts and platelet count. Urine was collected at the time of necropsy from the bladders of two moribund rabbits via aspiration for urinalysis. Maternal liver weights were recorded and sections of skin from the application site were collected from all animals at caesarean section. In addition, liver, kidney, spleen, bone marrow (sternum and vertebra) and urinary bladder were collected at either caesarean section or necropsy.

Ovaries and uterine content:

Following caesarean section, the number of corpora lutea and the number and position of implantations, resorptions and live or dead fetuses were recorded. The uteri of apparently non pregnant females were stained and examined for evidence of early implantation sites.

Fetal examinations:

Fetal examinations included litter size, number of dead fetuses, foetuses weights, crown-rump length measurement, sex determination and external alterations.

All fetuses were preserved and examined for skeletal alterations.

The number of fetuses (and litters) externally examined from the control, 300, 600 and 1000 mg/kg bw/day/ groups were 128 (17), 142 (20), 136 (15) and 49 (5), respectively; one half of each litter was examined for evidence of visceral alterations.

Statistics:

Statistical assessment: Maternal and fetal body weights, absolute and relative organ weights, hematologic variables and fetal length data were analyzed using a parametric or nonparametric analysis of variance followed by a Dunnett's test or the Wilcoxon rank sum test with Bonferroni's correction where appropriate. Preimplantation loss, resorptions, and fetal alterations were analyzed by a censored Wilcoxon test with Bonferroni's correction. Corpora lutea, implants and litter size were analyzed with a nonparametric analysis of variance followed by the Wilcoxon rank sum test with Bonferroni's correction. Pregnancy rates were analyzed by the Fisher's exact probability test and fetal sex ratios were analyzed by a binomial distribution test. The critical value for statistical significance was p<0.05.

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Four rabbits in the 600 mg/kg bw/day group and 3 in the 1000 mg/kg bw/day group had darkened areas of skin at the application site. Staining in the perineal region or dark colored urine was noted in several animals in these groups. Nine rabbits in the 1000 mg/kg bw/day and five in the 600 mg/kg bw/day groups died or were killed moribund. Most deaths occurred between gestation days 11 and 18. Most of these animals had dark colored urine in the bladder, jaundice and dark kidneys. Gross findings were consistent with hemolysis. In moribund animals for which hematological parameters were evaluated, red blood cell and platelet counts were severely depressed, reticulocytes were elevated, and red cell fragility was increased. There were no intact red blood cells in the urine sediment. Blood from animals that survived treatment with 600 or 1000 mg/kg bw/day appeared normal. The specific cause of death for 3 animals (2 at 600 mg/kg bw/day and one at 1000 mg/kg bw/day) could not be determined. With the exception of 5 animals that had already survived to day 28 due to staggered initiation, all remaining animals of the 1000 mg/kg bw/day group that survived to day 18 were killed on this day for humane reasons with no further observations. Animals in the 600 (N = 20) and 1000 mg/kg bw/day (N = 5) groups that survived to day 28 of gestation had no evidence of treatment-related effects. No signs of maternal toxicity were seen at 300 mg/kg bw/day. No differences in body weight gains or absolute or relative liver weights were observed between treated rabbits or controls.

Dose descriptor:

LOAEL

Effect level:

ca. 600 mg/kg bw/day (nominal)

Basis for effect level:

mortality

Dose descriptor:

NOAEL

Effect level:

ca. 300 mg/kg bw/day (nominal)

Basis for effect level:

other: maternal toxicity

Dose descriptor:

LOAEL

Effect level:

> 600 mg/kg bw/day (nominal)

Basis for effect level:

other: as no biologically significant effects were seen

Dose descriptor:

NOAEL

Effect level:

600 mg/kg bw/day (nominal)

Basis for effect level:

other: no adverse effects

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
Gestational parameters and developmental toxicity:
Treatment with 300 or 600 mg/kg bw/day had no adverse effect on the pregnancy rate, the number of corpora lutea, implantations, resorbed implantations, or live fetuses per litter or fetal body measurements.
Teratogenicity:
Treatment with up to 600 mg/kg bw/day had no effect on the incidence or type of external, visceral or skeletal malformations. Single occurrences of hemivertebrae and clinodactyly were observed among litters of dosed animals. The low incidences of these malformations are considered to be of sporadic occurrence and not indicative of a treatment-related effect. Fetuses from the 5 animals treated with 1000 mg/kg bw/day that survived to day 28also did not exhibit external, visceral or skeletal alterations (No statistical evaluations were performed on these data).

Dose descriptor:

NOAEL

Effect level:

600 mg/kg bw/day

Sex:

not specified

Basis for effect level:

other: no signs of teratogenicity at this dose level

Abnormalities:

not specified

Developmental effects observed:

not specified

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subacute

Species:

rat

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

600 mg/kg bw/day

Study duration:

subacute

Species:

rat

Additional information

In prenatal developmental toxicity studies, no effects on the developing foetus were seen in rats and rabbits (BASF AG, 2006 and Dow Chemical USA, 1985 and 1987).

In rats, oral administration of 2-phenoxyethanol elicited distinct signs of maternal toxicity at a dose level of 1,000 mg/kg bw/day (BASF AG, 2006). The test compound had no influence on gestational parameters and induced no signs of developmental toxicity up to and including the highest test dose of 1,000 mg/kg bw/day. In particular, there were no indications of teratogenic effects, which were causally related to the test substance. The NOAEL for maternal toxicity is 300 mg/kg bw/day. The NOAEL for prenatal developmental toxicity was 1,000 mg/kg bw/day.

In rabbits, dermal administration of 600 and 1000 mg/kg bw/day resulted in intravascular red blood cell haemolysis and death of some dams (Dow Chemical USA, 1985 and 1987). No treatment-related malformations occurred. Also fetuses from animals treated with 1000 mg/kg bw/day which survived to day 28 did not exhibit external, visceral or skeletal alterations. The NOAEL for teratogenicity and embryotoxicity was >600 mg/kg bw/day and for maternal toxicity was 300 mg/kg bw/day.

Toxicity to reproduction: other studies

Additional information

Not required.

No relevant data available (literature search was performed).

Justification for classification or non-classification

The available data is conclusive but not sufficient for classification.