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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:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: According to ECHA Practical Guide 6 the maximum score for read across is rel. 2

Data source

Reference
Reference Type:
publication
Title:
Postnatal developmental of rat pups after maternal exposure to Diethanolamine
Author:
Price CJ et al.
Year:
2005
Bibliographic source:
Birth Defects Research (Part B) 74, 243-254

Materials and methods

Principles of method if other than guideline:
Timed-mated Sprague-Dawley rats were dosed (0, 50, 125, 200, 250, or 300 mg DEA/kg/day, p.o.) on gestational days (GD) 6–19. Dams and pups were monitored for body weight, feed/water intake, clinical signs, litter size, and sex ratio. At necropsy (PND 21), maternal liver and kidney weights and number of uterine implantation sites were recorded.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Diethanolamine
- Molecular formula (if other than submission substance): C4H11NO2
- Molecular weight (if other than submission substance): 105.136

Test animals

Species:
rat
Strain:
Sprague-Dawley
Details on test animals and environmental conditions:
TEST ANIMALS
- Strain: Sprague-Dawley-derived outbred albino CD rats (Crl:CD (SD)BR VAF/Plus)
- Source: Charles River Laboratories, Raleigh, NC, US
- Weight at study initiation: 221-275 g (mean body weight did not differ among groups on GD 0)
- Housing: individually in solid-bottom polycarbonate cages with stainless steel wire lids
- Diet and water: ad libitum
- Acclimation period: 10 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-23 (65.6-75.2 °F)
- Humidity (%): 39-70
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on exposure:
Administration volume: 5 mL/kg
Diethanolamine was formulated in distilled (Pico) water at nominal concentrations of 10–60 mg/mL, and pH was adjusted to 7.4 +/- 2 with hydrochloric acid.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Each nominal concentration of DEA in water was sampled before use and analyzed by G.C. to verify concentration of the test chemical. Found concentrations ranged from 97.8–101.2 % of their respective nominal concentrations.
Details on mating procedure:
After a 10-day quarantine, individual breeding pairs were cohabited overnight. The morning on which sperm were found in the vaginal lavage (Hafez, 1970) was designated as GD 0.
Duration of treatment / exposure:
gestation day 6 - 19
Frequency of treatment:
once daily in the mornings
Duration of test:
approx. 40 days
No. of animals per sex per dose:
12 pregnant females plus 10 additional sentinel females
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: Dose selection was based primarily on earlier studies in rats. The lowest dose (50 mg/kg/day) was within the range associated with mild hematotoxicity in F344 female rats in a 13-week study. The highest dose (300 mg/kg/day) was expected to cause significant maternal toxicity including possible morbidity or mortality.

Examinations

Maternal examinations:
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: at least once daily on GD 0–5 and on GD 20 through termination; on GD 6–19 daily for clinical condition and signs of toxicity at dosing and approx. 1–2 hr after each dose administration. Beginning on GD 20, timed-mated females were checked twice daily (morning and afternoon) for evidence of littering.

FOOD CONSUMPTION: Yes
- Time schedule for examinations: GD 0, 6, 9, 12, 15, 18, and 20 for all timed-mated females, as well as PND 0, 4, 7, 14, and 21 for dams with litters.

WATER CONSUMPTION: Yes
- Time schedule for examinations: GD 0, 6, 9, 12, 15, 18, and 20 for all timed-mated females, as well as PND 0, 4, 7, 14, and 21 for dams with litters.

BODY WEIGHT: Yes
- Time schedule for examinations: GD 0, 6-20, and PND 0, 4, 7, 14, and 21 for dams with litters

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 24 if female sfailed to deliver a litter or on PND21 for dams with litter
The body, liver, and paired kidneys of each timed-mated female were weighed. Thoracic and abdominal cavities were examined. Visible uterine implantation sites were counted.
Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:
Naturally delivered litters were evaluated for clinical signs, litter size, pup sex and individual pup body weight on PND 0, 4, 7, 14, and 21. Pups were examined for external malformations or variations on PND 0. Pups were subjected to gross necropsy on PND 7 (culling) or PND 21 (scheduled termination).
Statistics:
Statistical procedures were based on SAS software (Version 6.12; SAS Institute, Inc., Cary, NC), and the alpha level was 0.05. Nonparametric tests applied to continuous variables included the Kruskal-Wallis one-way analysis of variance by ranks for among-group differences and, if significant (p < 0.05), the Mann- Whitney U-test for pairwise comparisons to the vehicle control group. A one-tailed Mann-Whitney U-test was used for all parameters, except that maternal and pup body weight parameters, and maternal feed and water consumption were examined using a two-tailed test. Jonckheere's test for k-independent samples was used to identify significant dose-response trends. Nominal scale measures were analyzed by Chi-Square test for independence for differences among treatment groups and by the Cochran-Armitage test for linear trend on proportions. When Chi-Square test showed significant (p < 0.05) differences among groups, then a one-tailed Fisher's exact probability test, with appropriate adjustments for multiple comparisons, was used for pairwise comparisons between control and DEA treated groups. A probit analysis was used to determine the maternal LD10 in this study.

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:
Maternal toxic effects:yes

Details on maternal toxic effects:
Cited from publication: "Exposure to DEA at 50 mg/kg/day on GD 6–19 was not associated with any significant maternal toxicity during or after the treatment period. Maternal relative water intake was transiently affected during early gestation (125 and 250 mg/kg/day) but was comparable to controls for all measurement periods after GD 12. Maternal absolute kidney weight was increased on PND 21 (>/= 125 mg/kg/day), thus
indicating persistence of DEA-induced toxicity for up to ~3 weeks after cessation of exposure. Reduced maternal body weight and weight change, as well as reduced relative feed intake, were noted at >/= 200 mg/kg/day." "Maternal morbidity or mortality occurred at 200 and 250 mg DEA/kg/day, and all females at 300 mg/kg/day were terminated early due to excessive toxicity."

Effect levels (maternal animals)

Dose descriptor:
NOAEL
Effect level:
50 mg/kg bw/day
Basis for effect level:
other: maternal toxicity

Maternal abnormalities

Abnormalities:
effects observed, treatment-related
Localisation:
other: "Maternal morbidity or mortality occurred at 200 and 250 mg DEA/kg/day, and all females at 300 mg/kg/day were terminated early due to excessive toxicity." (Cited from the publication)

Results (fetuses)

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

Details on embryotoxic / teratogenic effects:
Cited from publication: " Significant developmental toxicity was observed after maternal exposure to DEA throughout the embryo/fetal period of gestation (GD 6–19). Specifically, postimplantation mortality was increased at >/= 200 mg/kg/day on PND 0, and early postnatal mortality (PND 0–4) was increased at >/=125 mg/kg/day. Pup body weight was reduced at >/= 200 mg/kg/day, with females somewhat more affected than males. When expressed as a percentage of control weight, pup body weight deficits were at their greatest during the early postnatal period. Statistically significant differences were also evident at the end of the lactational period, however, approximately 3 weeks after cessation of exposure.

Effect levels (fetuses)

Dose descriptor:
NOAEL
Effect level:
50 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Postimplantation mortality was increased at >/= 200 mg/kg/day on PND 0, and early postnatal mortality (PND 0–4) was increased at >/=125 mg/kg/day. Pup body weight was reduced at >/= 200 mg/kg/day, with females somewhat more affected than males.

Fetal abnormalities

Abnormalities:
not examined

Overall developmental toxicity

Developmental effects observed:
not specified

Any other information on results incl. tables

The substance contains approx. 40 % 2,2'-iminodiethanol (CAS No 111-42-2), therefore data of 2,2'-iminodiethanol are relevant for toxicological assessment and were thus included in the IUCLID.

Applicant's summary and conclusion

Executive summary:

Summary according to abstract of publication: Timed-mated Sprague-Dawley rats were dosed (0, 50, 125, 200, 250, or 300 mg DEA/kg/day, p.o.) on gestational days (GD) 6–19. Dams and pups were monitored for body weight, feed/water intake, clinical signs, litter size, and sex ratio. At necropsy (PND 21), maternal liver and kidney weights and number of uterine implantation sites were recorded.

The high-dose group was terminated early due to excessive toxicity. Maternal effects included decreased body weight and relative feed intake (>/= 200 mg/kg/day), transiently reduced relative water intake (125 and 250 mg/kg/day), and increased absolute kidney weight (>/= 125 mg/kg/day). Postimplantation loss (PND 0) and pup mortality (PND 0–4) were increased (>/= 200 and >/= 125 mg/kg/day, respectively). Pup body weight was reduced (>/= 200 mg/kg/day) as late as PND 21.

This study demonstrates reduced postnatal growth and survival after gestational exposure to DEA, persistence of toxic effects through the end of lactation, possibly due to long elimination half-life, and maternal and developmental toxicity no-observed-adverse-effect level (NOAELs) (50 mg/kg/day) and lowest-observed-adverse-effect level (LOAELs) (125 mg/kg/day) for oral DEA exposure during embryo/fetal development in the rat.