2-ethylaminoethanol

Developmental toxicity / teratogenicity

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:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study; GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EPA OPPTS 870.3650 Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-methylaminoethanol

EC Number:

203-710-0

EC Name:

2-methylaminoethanol

Cas Number:

109-83-1

IUPAC Name:

2-(methylamino)ethanol

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report): Methylaminoethanol (Test item No.07/0540-2)
- Substance type: organic
- Physical state: colorless liquid
- Analytical purity: 99.7 area-% (Analytical Report: 07L00323)

- Purity test date: November 06-07, 2007
- Lot/batch No.: from continuous production, production date 24 Oct 2007
- Expiration date of the lot/batch: 24 Oct 2009


- Stability under test conditions: The stability of the test item under storage conditions over the test period was guaranteed by the sponsor, and the sponsor holds this responsibility
- Storage condition of test material: Room temperature, under N2

Test animals

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
- Age at study initiation: 11-13 weeks
- Weight at study initiation: The weight variation of the animals used did not exceed 20 percent of the mean weight of each sex.
- Fasting period before study: Animals were fasted prior to blood collection for clinical chemistry and haematology
- Housing: individually in type M III polycarbonate cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: yes, 10 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C):20-24 °C,
- Humidity (%):30-70%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: The test substance was applied as a solution. To prepare the solution, the appropriate
amount of test substance was weighed out depending on the desired concentration. Then the vehicle (highly deionized water) was filled up to the desired volume, subsequently mixed using a magnetic stirrer.
The test-substance solutions were prepared in such intervals that the stability was guaranteed.

VEHICLE
- highly deionized water
- Concentration in vehicle:0.5, 1.5 and 4.5 g/100 mL
- Amount of vehicle (if gavage): 100 mL

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The analyses of the test-substance preparations were carried out at the Analytical Chemistry Laboratory of the Experimental Toxicology and Ecology of BASF SE. The stability of the test substance in highly deionized water at room temperature for a period of 10 days was proven before the start of the administration period (Project No.: 01Y0540/078008). The concentration control analyses revealed that the values were in the expected range of the target concentration, i.e. were in a range of about 90.1-102.2% of the nominal concentration.

Details on mating procedure:

- M/F ratio per cage: 1/1
- Length of cohabitation: overnight starting at 13 days after the beginning of treatment to produce litter (F1 generation pups). Mating pairs were from the same test group. Mating was discontinued as soon as sperm was detected in the vaginal smear.
- Proof of pregnancy: [sperm in vaginal smear] referred to as [day 0 ] of pregnancy
- Further matings after two unsuccessful attempts: [no]
- After successful mating each pregnant female was caged ( Pregnant females were provided with nesting material (cellulose wadding) toward the end of pregnancy.):
- Any other deviations from standard protocol: no

Duration of treatment / exposure:

The duration of treatment covered a 2-week pre-mating and mating period in both sexes, approximately 1 week post-mating in males, and the entire gestation period as well as 4 days of lactation in females (35 days for males and 55 days for females).

Frequency of treatment:

daily at the same time in the morning

Duration of test:

approximately 35 days for males and 55 days for females

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 50, 150 and 450 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Details on study design:

- Rationale for animal assignment: randomized
- Rationale for selecting satellite groups: no satellite groups
- Post-exposure recovery period in satellite groups: not applicable
- Section schedule rationale (if not random): randomized

Examinations

Maternal examinations:

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
Generally, food consumption was determined once a week (in a period of 7 days) for female parental animals, with the following exceptions:
• Food consumption was not determined during the mating period (male and female F0 animals).
• Food consumption of the F0 females with evidence of sperm was determined on GD 0, 7, 14 and 20.
• Food consumption of F0 females, which gave birth to a litter, was determined on PND 0 and 4.
Food consumption was not determined in females without positive evidence of sperm (during the mating period of dams used in parallel) and females without litter (during the lactation period of dams used in parallel).

Ovaries and uterine content:

After sacrifice of the female animals the uterus and ovaries were removed and the
implantation sites were counted. To determine the number of implantation sites in apparently
non-pregnant animals, the uteri from those females were stained in 10% ammonium sulfide
solution for about 5 minutes according to the method of Salewski.
Then, the respective uteri were rinsed carefully with fresh tap water. The implantation sites
were recorded for the calculation of the postimplantation loss.

Fetal examinations:

Litter/fetal observations: All pups delivered from the F0 parents were examined as soon as possible on the day of birth to determine the total number of pups and the number of liveborn and stillborn pups in each litter. Pups, which died before the first determination of their status on the day of birth, were defined as stillborn pups. At the same time, the pups were also examined for macroscopically evident changes. The following parameters were examined in [F1] offspring:[number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities, other:] The live pups were examined twice daily for mortality and daily for clinical symptoms (including gross-morphological findings) during the clinical inspection of the dams.The pups were weighed one day after birth (PND 1) and on day 4 after birth.

SACRIFICE- The F1 offspring not selected as parental animals and were sacrificed at [4] days of age. All surviving pups (after sacrifice on PND 4 by means of anesthesia and exsanguination), all stillborn pups and those pups that died before schedule, were examined externally, eviscerated and their organs were assessed macroscopically. All pups without any notable findings or abnormalities were discarded after their macroscopicevaluation.- These animals were subjected to postmortem examinations (macroscopic and/or microscopic examination) as follows: all gross lesions, lungs and spinal cord (cervical, thoracic and lumbar cord) were preserved in neutrally buffered 4 % formaldehyde solution and then analyzed.GROSS NECROPSY- Gross necropsy consisted of [external and internal examinations including the cervical, thoracic, and abdominal viscera. Possible cause of death was determined for pups born or found dead HISTOPATHOLOGY: All gross lesions and lungs were fixed.

Statistics:

Body weight and body weight change (for the pup weights, the litter means were used) number of mating days, duration of gestation, number of pups delivered per litter, implantation sites, post implantation loss: DUNNETT-test (two-sided)
Reproduction indices, females with stillborn pups, females with all stillborn pups, live birth index, pups stillborn, pups died, pups cannibalized, pups sacrificed moribund, viability index, number of litters with affected pups at necropsy : FISHER'S EXACT test
Proportions of affected pups per litter with necropsy observations: WILCOXON-test (one-sided)

Indices:

Reproductive indices:
Male mating index %: (number of males with confirmed mating* /number of males placed with females)x100; *- defined by a female with vaginal sperm or with implants in utero;
Male fertility index (%): (number of males proving their fertility */number of males placed with females)x100; * - defined by a female with implants in utero;
Female mating index (%): (number of females mated */ number of females placed with males)x100; * - defined as the number of females with vaginal sperm or with implants in utero;
Female fertility index (%): (number of females pregnant */number of females mated **)x100; * defined as the number of females with implants in utero; ** defined as the number of females with vaginal sperm or with implants in utero.
Gestation index (%): (number of females with live pups on the day of birth/number of females pregnant *); * - defined as the number of females with implants in utero;
Live birth index(%): (number of liveborn pups at birth/total number of pups born)x100;
Post implantation loss (%): (number of implantations minus number of pups delivered/number of implantations)x100

Offspring viability indices:
Viability index (%): (number of live pups on PND4/number of liveborn pups on the day of birth)x100. The same for sex ratio: (number of live male or female pups on day 0/ 4/number of live male and female pups on day 0/ 4)x100

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
(see section 7.5.1 for general findings, section 7.8.1 for reproductive)

Test group 3 (450 mg/kg bw/d)
F0 maternal animals
• Clinical Examinations:
o Poor general state in two female animals in study weeks 1, 6 and 7 as well as in up to four female
animals from GD 11 onwards.
o Discolored urine in all females during pre-mating, mating and the complete gestation period
o Salivation in six female animals in study weeks 1, 6 and 7 as well as in up to two female animals from GD 2 onwards
o Decreased food consumption in female animals during the first two study weeks.
o Body weight loss in females between GD 14-20
• Fertility:
o Female fertility index of 10%
o Reduced number of implantation sites
o No pups delivered
• Clinical Pathology:
o Increased RBC, haemoglobin and hematocrit values
o Increased sodium, urea and total bilirubin concentrations
o Shortened prothrombin time
o Increased relative reticulocyte counts, total protein and albumin values in female rats
o Increased incidence of blood and higher leucocyte counts in the urine of females
• Pathology:
o Increased relative kidney weights
o Decreased absolute and relative weights of ovaries
o Increased relative spleen weights
o Tubular degeneration in the kidneys of nine females
o Occurrence of cysts in the ovaries of all females
o Occurrence of vacuolization of the sex cord stroma in the ovaries of all females
o Increased incidence of extramedullary hematopoiesis in the spleen of most females
o Higher severity of hemosiderin storage in the spleen of females

Test group 2 (150 mg/kg bw/day):
F0 maternal animals
• Clinical Examinations:
o One female animal was sacrificed on GD 23 because of an inability to deliver.
o Decreased food consumption in females between GD 14 and 20.
o Body weight loss in females between GD 14-20
• Fertility:
o Female fertility index of 50%
o Reduced number of implantation sites
o Only one stillborn pup; no liveborn pups delivered
• Clinical Pathology:
o Increased RBC, haemoglobin and hematocrit values in rats of both sexes
o Increased sodium and total bilirubin concentrations
o Shortened prothrombin time
o Increased total protein and albumin values
o Increased incidence of blood in the urine
• Pathology:
o Increased relative kidney weights
o Increased relative spleen weights
o Tubular degeneration in the kidneys of nine females
o Occurrence of vacuolization of the sex cord stroma in the ovaries of four females
o Increased incidence of extramedullary hematopoiesis in the spleen of a few females
o Higher severity of hemosiderin storage in the spleen

Test group 1 (50 mg/kg bw/day)
F0 maternal animals
• Clinical Examinations:
o No test-substance related, relevant findings were observed.
• Fertility:
o No impairment of fertility was observed.
• Clinical Pathology:
o No test-substance related, relevant findings were observed.
• Pathology:
o No test-substance related, relevant findings were observed

Effect levels (maternal animals)

Dose descriptor:

NOAEL

Effect level:

50 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
F1 pups (50 mg/kg bw/day)
o No test-substance related, relevant findings were observed.

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

under the conditions of the reproduction/developmental toxicity screening test the NOAEL (no observed adverse effect level) for embryotoxic / teratogenic effects was 50 mg/kg bw/d.