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Toxicological information

Developmental toxicity / teratogenicity

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Administrative data

Endpoint:
developmental toxicity
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Study period:
04 February 1986 to 20 March 1986
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Performed to GLP and reported in a high level of detail, the study is not performed to a standardised guideline and uses lower group numbers than is recommended in OECD 414 guideline, however the study is in basic compliance with the current standardised guidelines and was performed in line with good scientific principles. The study was a range-finding study for a definitive developmental study. Although the study had very specific objectives, all the parameters for assessing developmental toxicity were included. The read-across approach has been used since phenylethyl alcohol is structurally similar to the test material but is more toxicologically active. The results presented are therefore taken to be the worst case scenario.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report Date:
1988

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Principles of method if other than guideline:
Undiluted phenethyl alcohol was administered to Crl rats dermally at 0.07, 0.14, 0.28, 0.43 or 0.70 mL/kg/day from gestation day 6 through 15 at 24 hour intervals under an occluded dressing. Emphasis was placed on identifying whether vestigial cervical ribs in offspring were the most sensitive end point for developmental toxicity and whether they occurred in the absence of maternal toxicity. Signs of irritation were noted in all dams dosed with the test material, dose-dependently for onset, severity and duration.
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid (undefined)
Details on test material:
- Name of test material: 2-phenylethyl alcohol (PEA)
- Physical state: Liquid (clear, slightly yellowish, oily with a characteristic odour)
- Storage condition of test material: Ambient (room) temperate
- Calculated specific gravity: 11.2 g

Test animals

Species:
rat
Strain:
other: Crl
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: 61 days at receipt. Born on the 05 December 1985 and dosed on 04 March 1986.
- Weight at study initiation: 221-273 g (157 - 205 g on arrival).
- Housing: Individually in wire bottomed stainless steel cages, following cohabitation during mating period.
- Diet: ad libitum.
- Water: Reverse osmosis tap water, ad libitum.
- Acclimation period: 3 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 70 ± 2 ºF
- Humidity (%): 48-58%
- Air changes (per hr): 10 changes per hour
- Photoperiod (hrs dark / hrs light): 12 hours dark / 12 hours light

IN-LIFE DATES: From 04 February 1986 to 20 March 1986

Administration / exposure

Route of administration:
dermal
Vehicle:
unchanged (no vehicle)
Details on exposure:
TEST SITE
- Area of exposure: 7 x 5 cm area (shaved) from the intrascapular region.
- Type of wrap if used: Occluded dressing (5 x 5 cm), consisting of an aluminium foil patch (7 x 5 cm) covering all the shaved dorsal area, held in place by a medical-type adhesive bandage.
- Time intervals for shavings or clippings: Shaving was performed when necessary.

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): Dosages were applied using computer calculated mL/kg volumes of the neat test material. Up to 0.70 mL/kg bw/day (high dose and control animals).
- Constant volume used: no

USE OF RESTRAINERS FOR PREVENTING INGESTION: no
Analytical verification of doses or concentrations:
no
Details on analytical verification of doses or concentrations:
The test substance was applied neat, as supplied. The purity of the test substance was confirmed at the beginning and the end of dosing.
Details on mating procedure:
- Impregnation procedure: 130 health females were co-housed with male breeders.
- M/F ratio per cage: 1:1
- Length of cohabitation: Maximum of 4 days.
- Proof of pregnancy: vaginal plug or sperm in vaginal smear referred to as day 0 of presumed gestation.
Duration of treatment / exposure:
Gestation days 6 to 15.
Frequency of treatment:
Daily
Duration of test:
Up to gestation day 20 (sacrifice).
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
0, 0.07, 0.14, 0.28, 0.43, 0.70 mL/kg/day
Basis:
nominal conc.
Remarks:
Doses / Concentrations:
0, 71.4, 143, 286, 439 and 714 mg/kg bw/day
Basis:
nominal conc.
No. of animals per sex per dose:
10 female rats were dosed at each test concentration.
Control animals:
other: yes, reverse osmosis water (0.70 mL/kg bw/day)
Details on study design:
- Dose selection rationale: In a previous study, dermal application of the test material to pregnant rats was associated with an increased incidence of fetuses with structural abnormalities. Increased incidences of very small cervical ribs were reported to be the only consistent and reliable indication of altered development at the low (0.14 mL/kg/day) and middle (0.43 mL/kg/day) dosages. The doses selected for this study were chosen to determine whether cervical ribs were the most sensitive indicator of developmental toxicity and whether the cervical ribs occurred in the absence of both maternal toxicity and/or other developmental effects of the test material and whether data appropriate for defining dosages for use in a definitive developmental toxicity study demonstrating both maternal and developmental no-effect levels could be obtained.

Examinations

Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily for viability.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Several times during acclimation cohabitation and pre-dosing periods. All mated female rats were evaluated on day 0 of presumed gestation and animals were checked several times daily during administration of the test material (including observations prior to administration and within 30 minutes of application). During the post-dosing period up until the end of the study, animals were examined daily.

BODY WEIGHT: Yes
- Time schedule for examinations: Bodyweights were recorded 4 times prior to the study assignment, on day 0 and daily throughout the dosage and post-dosage periods.

FOOD CONSUMPTION: Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Time schedule for examinations: Feed consumption was recorded for day 0 to 6 of presumed gestation, and daily throughout the dosing and post-dosing periods. Feed utilisation was calculated as g/kg of bodyweight/day.

POST-MORTEM EXAMINATIONS: Yes, animals were assessed for gross external and visceral lesions.
- Sacrifice on gestation day 20.
- Organs examined: Maternal tissues with gross lesions were retained for further assessment, with the exception of the uterus, all other tissues were discarded.
Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:
- Foetal weight: Yes: all per litter
- Foetal sex: Yes: all per litter
- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: one third of live foetuses per litter
- Skeletal examinations: Yes: all per litter
- Head examinations: Yes: one third of live foetuses per litter
Statistics:
The level of statistical significance for all observations in this study was considered to be P ≤ 0.05.
Maternal clinical signs, pregnancy incidence, abortion, death and total resorption were analysed for homogeneity using the variance test of the binomial distribution.
Maternal bodyweight, bodyweight change, feed consumption and feed utilisation were based on surviving pregnant dams with at least one live pup on day 20. Bartlett’s test of homogeneity of variances and the Analysis of Variance was used to assess maternal bodyweight data and the litter averages for foetal bodyweight, foetal ossification sites, percent dead or resorbed conceptus, percent male foetuses and percent of foetuses with alterations. Where the analysis of Variance was significant, where appropriate the parameters were assessed by Dunnett’s test in order to identity statistical significance of individual groups. If Analysis of Variance was not appropriate, then the Kruskal-Wallis test was used. Where this reached statistical significance, Dunn’s method of multiple comparisons was used to identify the statistical significance of individual groups.
Count data at Caesarean-sectioning were evaluated by the Kruskal-Wallis test. Where these reached statistical significance, Dunn’s method of multiple comparisons was employed to identify statistical significance of individual groups.
The variance test for homogeneity of the binomial distribution was used to analyse all data represented as a proportion.
Indices:
Presence of cervical rib
Average percentage of resorbed conceptuses
Live male foetuses per litter

Foetal alterations were defined as: 1) malformations (irreversible changes); and 2) developmental changes (reversible accelerations or delays of development).
Historical control data:
Historical control data was available for comparison. The historical control data was generated by the testing laboratory between 1983 and 1985.

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:
Maternal toxic effects:yes

Details on maternal toxic effects:
No maternal animals died during the course of the study.
At 0.70 mL/kg bw/day, ptosis and urine-stained abdominal fur was noted. Ptosis occurred in six (p<0.01) high dosage group dams on a total of 19 days; this sign was not observed in any other test groups in the study. Urine stained abdominal fur was observed for two or three rats in each dosage group. Two high dosage group rats exhibited this for a total of 12 days; this generally occurred no more than twice for the control rats and the rats in the other four dose groups.
No other clinical observation was attributed to administration of the test material. All other clinical signs were single events or were not statistically significant (p>0.05).
Skin reactions were noted at all dose levels with the test material, with increased incidences of rats with low levels (grade 1) of erythema and/or desquamation. The onset, severity and duration were dose-dependent.
At necropsy, one dam in the 0.28 mL/kg/day group and three rats in the 0.70 mL/kg/day group had small lesions present within the application area. In the high dose group the incidence of these skin lesions was significantly increased (p<0.01). The skin lesions were considered effects of dermal application of neat test material.
No other lesions observed at necropsy were attributed to an effect of exposure to the test material, as the incidences were not dosage-dependent or statistically significant.
Administration of the test material did not inhibit average maternal body weight or body weight gain in a consistent dose-dependent manner. Administration of the initial dosage on day 6 of gestation resulted in weight loss (decreased average maternal body weight) in all dose groups, compared with the pre-dosage bodyweights; weight loss was greatest for the control group. The control group had the greatest average weight gain after the second dose was given on day 7 of gestation. A small, inhibitory effect on the average maternal body weight gain occurred for dams given the 0.14 (P<0.01), 0.43 (P > 0.05) and 0.70 mL/kg/day (P<0.01) doses. This response pattern did not persist; no other significant difference (P>0.05) for average maternal body weight change values occurred among the six treatment groups.
Average maternal feed consumption and feed utilization values did not reveal and dose-related patterns. Both were increased after the first and tenth doses were given to dams in all groups administered with the test material compared to the control. For the treated groups, these parameters were decreased, after the third dose was administered. Average maternal feed consumption between days 12-13 of gestation was found to be significantly increased (P<0.05) for the high dose group. There were no other dose-dependent patterns or significant differences.
Pregnancy occurred for in all of the control rats. In the treatment groups, nine, ten, nine, ten and eight of the ten rats per group administered with 0.07, 0.14, 0.28, 0.43 and 0.70 mL/kg bw/day test material, respectively were pregnant. No pregnant dam resorbed all of its litter.
Administration of the test material did not adversely affect the averages for corpora lutea, implantations, litter sizes or resorptions. Values for these parameters were similar and did not reach statistical significance.

Effect levels (maternal animals)

open allclose all
Dose descriptor:
NOAEL
Effect level:
<= 0.43 other: mL/kg bw/day
Based on:
test mat.
Basis for effect level:
other: maternal toxicity
Dose descriptor:
NOAEL
Effect level:
<= 0.07 other: mL/kg bw/day
Based on:
test mat.
Basis for effect level:
other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
Litter Data:
Average live foetal bodyweights were decreased for litters of dams administered with the test substance. This was statistically significant (P < 0.05 to P<0.01) for litters of dams administered with and above 0.14 mL/kg bw/day. The average foetal weight in the control litters averaged 3.40 g, in the lowest dose group, the average foetal weight was 3.16 g; and 3.14 (P < 0.05), 3.11(P < 0.05), 2.97 (P < 0.01) and 2.99 (P < 0.01) g for litters of dams dosed with 0.14, 0.28, 0.43 and 0.70 mL/kg bw/day, respectively.
Administration of the test substance did not affect the average percentage of resorbed conceptuses or of live male foetuses per litter, as compared with control values. Differences observed for these parameters were neither dose—dependent nor significant (P>0.05).
Foetal Alterations:
Foetal alterations were defined as: 1) malformations (irreversible changes); and 2) developmental changes (reversible accelerations or delays of development).

126, 111, 134, 143, 143 and 122 foetuses from 10, 9, 10, 9, 10 and 8 litters from the 0(Vehicle), 0.07, 0.14, 0.28, 0.43 and 0.70 mL/kg bw/day, respectively, were examined for gross external alterations and skeletal alterations and for average numbers of foetal ossification sites. The thoracic and abdominal viscera of 45, 40, 49, 52, 51, and 45 of these respective foetuses were examined for soft tissue alterations.
Administration of 0.43 and 0.70 mL/kg bw/day was found to increase the number of litters with foetal alterations; these increased litter values did not reach statistical significance (P > 0.05). The incidence of altered foetuses was significantly increased (P < 0.05 to P < 0.01) for the two highest dosing groups, as was the average percentage of altered foetuses per litter.
These increased incidences of foetal alteration indicated a dose-dependent pattern of significant increases (P < 0.05 to P < 0.01) in the number of foetuses that had incompletely ossified (hypoplastic) ribs, wavy ribs (0.43 and 0.70 mL/kg bw/day) and/or cervical rib(s) (0.70 ml/kg bw/day only).
Increased incidences of foetuses with delayed ossification of the sternebrae and/or pelvis occurred in all treatment groups. These foetal alterations were not observed for the control group. The litter incidence for foetuses with delayed pelvic ossification was significantly increased (P < 0.05 to P < 0.01) for all dose groups. Neither of these foetal alterations had incidences that demonstrated a clear dose-dependent pattern. Further analysis of the foetal ossification site averages for each litter clearly demonstrated delayed foetal development. Dosage-dependent decreases in ossification site averages occurred for litters of dams in all groups administered with the test substance. The decreases were statistically significant (P < 0.05 to P < 0.01) for metacarpals, hind paw phalanges (0.14 mL/kg bw/day and above), caudal vertebrae (0.28 mL/kg bw/day and above), forepaw phalanges (0.43 mL/kg bw/day and above) and sternal centers (0.07 mL/kg bw/day dosage).
Gross external, soft tissue and/or skeletal examination of the foetuses in this study did not reveal any other foetal alteration attributed the test substance. All other observed foetal alterations (both litter and individual) were not dose-dependent and/or did not reach statistical significance.

Gross External Alterations:
One 0.70 mL/kg bw/day foetus had a thread-like tail.

Soft Tissue Alterations:
No soft tissue alteration was observed for any foetus in this study

Skeletal Alterations:
- Malformation
Cervical rib occurred in 39(32.0%) (P < 0.01) of the foetuses from the eight (100%) (P < 0.01) litters in the high dose group. Differences between the control and those observed for all other dosage groups were not significant (P>0.05). Cervical rib occurred for three (2.4%) foetuses from three (30.0%) control litters and also one 0.07 mL/kg bw/day foetus (foetal incidence = 0.9%; litter incidence = 11.1%). No foetus of the 0.14 mL/kg bw/day dosage group had this alteration. Two (1.4%) foetuses from two (22.2%) litters of the 0.28 mL/kg bw/day group, and five (3.5%) foetuses from two (20.0%) litters of the 0.43 mL/kg bw/day group had cervical rib(s).
No other foetal skeletal malformations were observed.

- Delayed Ossification:
Incompletely ossified (hypoplastic) ribs occurred for 2(1.6%), 1(0.9%), 0, 0, 7(4.9%) (P < 0.05) and 9(7.4%) (P < 0.01) foetuses from 2(20.0%), 1(11.1%), 0, 0, 2(20.0%) and 4(50.0%) litters of the control, 0.07, 0.14, 0.28, 0.43 and 0.70 mL/kg bw/day groups, respectively.
In these same respective groups, wavy ribs occurred for 2(1.6%), 7(6.3%) (P < 0.01), 1(0.7%), 0, 9(6.3%) (P < 0.01) and 11(9.0%) (P < 0.01) foetuses from 2(20.0%), 3(33.3%), 1(10.0%), 0, 4(40.0%) and 4(50.0%) litters.
No control foetuses had incomplete ossification of sternal centers. In the 0.07, 0.15, 0.28 and 0.43 mL/kg bw/day dosage groups, respectively, 7(6.3%) (P < 0.01), 9(6.7%) (P < 0.01), 10(7.0%) (P < 0.01) foetuses and 13(9.1%) (P < 0.01) foetuses from 2(22.2%). 4(40.0%), 4(44.4%) and 5(50.0%) (P < 0.05) litters had one or more incompletely ossified sternal center. One (0.8%) foetus from a 0.70 mL/kg bw/day litter (12.5%) had this alteration.
Delayed ossification of the pelvis (incompletely ossified pubes and/or ischia) was observed only for foetuses of dams administered with the test substance. In the five respective dosage groups, 10(9.0%) (P < 0.01), 7(5.2%), 12(8.4) (P < 0.01), 24(16.8%) (P < 0.01) and 10(8.2%) (P < 0.01) of the foetuses from 3(33.3%) (P < 0.05), 3(30.0%) (P < 0.05), 4(44.4%) (P < 0.01), 8(80.0%) (P < 0.01) and 5(62.5%) (P < 0.01) litters had delayed pelvic ossification.

No other delay in ossification demonstrated a dose-dependent pattern. Low incidences of bifid centra in thoracic vertebra, incomplete ossification of the arches of lumbar vertebrae, incomplete ossification of the manubrium, and unossified sternal centers were recorded but not attributed to the administration of the test substance.

- Foetal Ossification Sites:
The number of ossified metacarpals per foetus averaged 3.74, 3.46, 3.30 (P < 0.01), 3.29 (P < 0.01), 3.26 (P < 0.01) and 3.10(P < 0.01) for the control, 0.07, 0.14, 0.28, 0.43 and 0.70 mL/kg bw/day dose groups, respectively. In these same respective litters, there was an average of 4.56, 3.18, 3.37 (P < 0.05), 3.03 (P < 0.05), 1.67 (P < 0.01) and 1.19 (P < 0.01) ossified hindpaw phalanges per foetus.
In the control, 0.07, 0.14, 0.28, 0.43 and 0.70 mL/kg bw/day dose groups, respectively there was an average of 5.13, 4.66, 4.75, 4.58 (P < 0.05), 4.43 (P < 0.05) and 3.85(P < 0.01) ossified caudal vertebrae per foetus. In these same respective litters, foetuses had an average of 4.92, 3.86, 4.42, 3.97, 2.80 (P < 0.01) and 2.64 (P < 0.01) ossified forepaw phalanges; sternal centers per foetus, the groups averages were 3.80, 3.73, 3.68, 3.70, 3.54 and 3.28 (P < 0.01), respectively.
All other differences in the average numbers of foetal ossification sites per litter were not dose—dependent, were within the expected range for foetuses of this strain and age and/or did not reach statistical significance.

Fetal abnormalities

Abnormalities:
not specified

Overall developmental toxicity

Developmental effects observed:
not specified

Any other information on results incl. tables

Table 1: Skin Reaction Summary

Dosage (mL/kg/day) Erythema Index Maximum Number Desquamation Index Maximum Number Fissuring Index Maximum Number
0 (vehicle) 16.0 5/10 12.0 3/10 0.0 0/10
7.5 1/10 0.0 0/10 0.0 0/10
0.07 24.0 4/10 20.0 5/10 0.0 0/10
12.5 2/10 22.5 3/10 0.0 0/10
0.14 41.0 7/10 57.0 9/10 3.0 1/10
5.0 2/10 60.0 7/10 0.0 0/10
0.28 43.0 7/10 59.0 7/10 3.0 1/10
50.0 6/10 72.5 6/10 0.0 1/10
0.43 76.0 9/10 80.0 9/10 4.0 2/10
57.5 8/10 102.5 8/10 5.0 1/10
0.70* 120.0 10/10 119.0 10/10 4.0 3/10
130.0 10/10 160.0 10/10 1.0 1/10

* Atonia and eschar were also observed for the high dosage group. During the dosage period, atonia had an index of 1.0 and occurred for 1/10 rats; during the post dosage period, atonia had an index of 10.0 and occurred for 1/10 rats. During the dosage period, eschar had an index of 11.0 and occurred for 3/10 rats; during the postdosage period, eschar had an index of 4.0 and occurred for 2/10 rats. Exfoliation and edema were not observed for rats in any of the dosage groups.

Table 2: Litter Data Summary

  Dosage Group (mL/kg/days 5-15 of presumed gestation)
0 (vehicle) 0.07 0.14 0.28 0.43 0.70
Litters examined day 20 N 10 9 10 9 10 8
Implantations mean± S.D. 13.5± 4.0 12.9 ± 4.9 14.3 ± 4.5 16.7 ± 1.0 15.4 ± 2.1 16.1 ± 1.2
Live foetuses mean± S.D. 12.6 ± 3.8 12.3 ± 4.89 13.4 ± 4.3 15.9 ± 0.8 14.3 ± 2.2 15.2 ± 2.0
Live fetal body weights (g/litter) mean± S.D. 3.40 ± 0.25 3.16 ± 0.22 3.14 ± 0.18* 3.11 ± 0.19* 2.97 ± 0.27** 2.99 ± 0.24**
Male foetuses mean± S.D. 3.49 ± 0.27 3.23 ± 0.27 3.21 ± 0.22* [9] 3.20 ± 0.22* 3.03 ± 0.27** 3.06 ± 0.26**
Female foetuses mean± S.D. 3.30 ± 0.24 3.11 ± 0.20 [8] 3.08 ± 0.19 3.01 ± 0.19* 2.89 ± 0.28** 2.93 ± 0.22**
% resorbed conceptuses/litter mean± S.D. 6.2 ± 6.6  4.1 ± 4.0 5.6 ± 7.0 4.5 ± 4.8 7.2 ± 5.3 5.7 ± 6.4
Live foetuses N 126 111 134 143 143 122
Live male foetuses N 70 54 70 73 82 55
% live male foetuses/total foetuses per litter mean± S.D. 56.2 ± 14.1 53.1 ± 22.4 47.5 ± 18.3 51 ± 8.9 56.8 ± 13.0 45.2 ± 9.8

* Significantly different from the vehicle control at P ≤0.05.

**Significant different from the vehicle control at P ≤ 0.01.

[N] number of values averaged.

Table 3: Fetal Alterations Summary

Dosage Group (mL/kg/days 6-15 of presumed gestation)
0 (vehicle) 0.07 0.14 0.28 0.43 0.70
Litters evaluated N 10 9 10 9 10 8
Foetuses evaluated N 126 111 134 143 143 122
Live foetuses N 126 111 134 143 143 122
Dead foetuses N 0 0 0 0 0 0
Litters with foetuses with any alteration observed N (%) 5 (50.0) 6 (66.7) 5 (50.0) 5 (55.6) 9 (90.0) 8 (100.0)
Foetuses with any alterations observed N (%) 6 (4.8) 20 (18.0) 15 (11.2) 23 (16.1) 44 (30.8)** 59 (48.4)**
% foetuses with an alteration/litter mean ± S.D. 4.40 ± 5.50 14.76 ± 21.54 13.89 ± 18.94 16.21 ± 21.32 30.18 ± 21.60* 49.60 ± 17.42**

* Significantly different from the vehicle control at P ≤0.05.

**Significant different from the vehicle control at P ≤ 0.01.

Table 4: Gross External Fetal-Alterations Summary

  Dosage Group (mL/kg/days 6-15 of presumed gestation)
0 (vehicle) 0.07 0.14 0.28 0.43 0.70
Litters evaluated N 10 9 10 9 10 8
Foetuses evaluated N 126 111 134 143 143 122
Live foetuses N 126 111 134 143 143 122
Dead foetuses N 0 0 0 0 0 0
TAIL:              
Thread-like              
Litter incidence N % 0 0 0 0 0 1 (12.5)
Fetal incidence N % 0 0 0 0 0 1 (0.8)

Table 5: Soft Tissue Fetal Alterations Summary

  Dosage Group (mL/kg/days 6-15 of presumed gestation)
0 (vehicle) 0.07 0.14 0.28 0.43 0.70
Litters evaluated N 10 9 10 9 10 8
Foetuses evaluated N 45 40 48 51 51 45
Live foetuses N 45 40 48 51 51 45
Dead foetuses N 0 0 0 0 0 0

** No soft tissue fetal alterations were found in this study

Table 6: Skeletal Fetal Alterations Summary

  Dosage Group (mL/kg/days 6-15 of presumed gestation)
0 (vehicle) 0.07 0.14 0.28 0.43 0.70
Litters evaluated N 10 9 10 9 10 8
Foetuses evaluated N 126 111 134 143 143 122
Live foetuses N 126 111 134 143 143 122
Dead foetuses N 0 0 0 0 0 0
SKULL:              
Supraoccipital, incompletely ossified              
Litter incidence N % 0 0 1 (10.0) 0 0 0
Fetal Incidence N % 0 0 1 (0.7) 0 0 0
Supraoccipital, not ossified              
Litter incidence N % 0 0 1 (10.0) 0 0 0
Fetal Incidence N % 0 0 1 (0.7) 0 0 0
VERTEBRAE:              
Cervical rib              
Litter incidence N % 3 (30.0) 1 (11.1) 0 2 (22.2) 2 (20.0) 8 (100.0)**
Fetal Incidence N % 3 (2.4) 1 (0.9) 0 2 (1.4) 5 (3.5) 39 (32.0)**
Thoracic, centra, bifid              
Litter incidence N % 1 (10.0) 3 (33.3) 2 (20.0) 0 1 (10.0) 2 (25.0)
Fetal Incidence N % 1 (0.8) 3 (2.7) 2 (1.5) 0 1 (0.7) 2 (1.6)
Lumbar, arch(es), incompletely ossified              
Litter incidence N % 0 0 0 1 (11.1) 0 2 (25.0)
Fetal Incidence N % 0 0 0 1 (0.7)  0 2 (1.6)
RIBS:              
Incompletely ossified (hypoplastic)              
Litter incidence N % 2 (20.0) 1 (11.1) 0 0 2 (20.0) 4 (50.0)
Fetal Incidence N % 2 (1.6) 1 (0.9) 0 0 7 (4.9)* 9 (7.4)**
One or more wavy              
Litter incidence N % 2 (20.0) 3 (33.3) 1 (10.0) 0 4 (40.0) 4 (50.0)
Fetal Incidence N % 2 (1.6) 7 (6.3)** 1 (0.7) 0 9 (6.3)** 11 (9.0)**
MANUBRIUM:              
Incompletely ossified               
Litter incidence N % 0 0 1 (10.0) 1 (11.1) 1 (10.0) 0
Fetal Incidence N % 0 0 1 (0.7) 1 (0.7) 1 (0.7) 0
STERNABRAE:              
One or more incompletely ossified              
Litter incidence N % 0 2 (22.2) 4 (40.0) 4 (44.4) 5 (50.0) 1 (12.5)
Fetal Incidence N % 0 7 (6.3)** 9 (6.7)** 10 (7.0)** 13 (9.1)** 1 (0.8)
One or more not ossified              
Litter incidence N % 0 1 (11.1) 2 (20.0) 1 (11.1) 2 (20.0) 3 (37.5)
Fetal Incidence N % 0 2 (1.8) 3 (2.2) 2 (1.4) 4 (2.8) 3 (2.4)
PELVIS:              
Pubes and/or ischia, incompletely ossified              
Litter incidence N % 0 3 (33.3)* 3 (30.0)* 4 (44.4)** 8 (80.0)** 5 (62.5)**
Fetal Incidence N % 0 10 (9.0)** 7 (5.2) 12 (8.4)** 24 (16.8)** 10 (8.2)**
Pubes and/or ischia, not ossified              
Litter incidence N % 0 0 1 (10.0) 0 2 (20.0) 1 (12.5)
Fetal Incidence N % 0 0 1 (0.7) 0 2 (1.4) 1 (0.8)

* Significantly different from the vehicle control at P ≤0.05.

**Significant different from the vehicle control at P ≤ 0.01.

Applicant's summary and conclusion

Conclusions:
Dosage dependent increasing scores for dermal irritation resulted from administration of all dosages of the test material as compared with control values. In addition, the 0.7 mL/kg/day dosage of the test material caused incidences of ptosis and/or urine-stained abdominal fur in the dams. On the basis of these findings, the neat test material was considered irritating to the skin of pregnant rats. Secondary effects of this irritation may have resulted in the observed altered fetal development.

Dosage dependent statistically significant observations of delays in fetal development (decreased average fetal body weight and delayed fetal ossification) resulted from administration of the test material at 0.14 mL/kg/day dosages and above. There were no treatment related soft tissue effects in foetuses. Significant increase in the incidence of foetuses with cervical ribs occurred for the 0.70 mL/kg/day group. All other foetal observations were considered to be reversible delays in ossification. Delayed ossification (sternum and/or pelvic) was noted in the all test material administered groups. Delayed pelvic ossification was found to be significant in all groups dosed with the test material, but neither alteration demonstrated a clear dosage dependent pattern. No skeletal malformations were observed.

Under the conditions of the study, on the basis of reduced fetal body weight, and ptosis and/or urine-stained abdominal fur in dams developmental and maternal no-effect levels for the test material were 0.07 and ≤ 0.43 mL/kg/day respectively, equivalent to 71.4 and ≤ 439 mg/kg bw/day.
Executive summary:
The developmental toxicity of phenylethyl alcohol was investigated by administering undiluted phenethyl alcohol to rats dermally at 0.07, 0.14, 0.28, 0.43 or 0.70 mL/kg/day from gestation day 6 through 15 at 24 hour intervals under an occluded dressing. Emphasis was placed on identifying whether vestigial cervical ribs in offspring were the most sensitive end point for developmental toxicity and whether they occurred in the absence of maternal toxicity. Signs of irritation were noted in all dams dosed with the test material, dose-dependently for onset, severity and duration. No maternal deaths occurred. Clinical signs of toxicity (ptosis and/or urine stained abdominal fur) were noted in the dams dosed with 0.70 mL.kg bw/day of the test material. Live foetal body weights were lower in litters from dams dosed with the test material, attaining statistical significance at doses of 0.14 mL/kg/day and above. Significant increase in the incidence of foetuses with cervical ribs occurred for the 0.70 mL/kg/day group. All other foetal observations were considered to be reversible delays in ossification. Delayed ossification (sternum and/or pelvic) was noted in the all test material administered groups. Delayed pelvic ossification was found to be significant in all groups dosed with the test material, but neither alteration demonstrated a clear dosage-dependent pattern. Under the conditions of the study, on the basis of reduced fetal body weight, and ptosis and/or urine-stained abdominal fur in dams (and excluding irritation), the developmental and maternal no-effect levels for the test material were ≤0.07 and ≤0.43 mL/kg/day respectively.