Diethyl bis(2-hydroxyethyl)aminomethylphosphonate

Endpoint summary

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Effects on fertility

Description of key information

NOAEL fertiliy and development ≥ 750 mg/kg bw/day (highest dose tested) (OECD 421, GLP, Key, Rel.1)

Link to relevant study records

Reference

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05 Jun - 24 Aug 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)

Version / remarks:

1995

Deviations:

yes

Remarks:

gross pathological findings were not examined in the F1 generation

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Specific details on test material used for the study:

- Date of receipt: 29 Apr 2005
- Color: amber
- Form: liquid
- Storage conditions: room temperature (approx. 22 ± 3°C), protected from light

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Taconic Farms, Germantown, USA
- Females nulliparous and non-pregnant: yes
- Age at study initiation: (P) x 8 wks
- Weight at study initiation: (P) Males: 190-214 g; Females: 161-173 g
- Housing: individually in stainless steel cages; one male and one female in polycarbonate shoebox with corncob bedding during mating period.
- Diet: Harlan Teklad Certified Rodent Diet 8728C ad libitum
- Water: tap water from the city of Chicago ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-26
- Humidity (%): 30-70
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 05 Jun 2005 To: 24 Aug 2005

Route of administration:

oral: gavage

Vehicle:

water

Remarks:

deionized

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Rate of preparation of diet: every week
- Mixing appropriate amounts with: water
- Storage temperature of food: room temperature (approx. 22 ± 3°C)

VEHICLE
- Concentration in vehicle: 10, 50 and 150 mg/mL
- Amount of vehicle: 5 mL/kg bw

Details on mating procedure:

- M/F ratio per cage: 1/1
- Length of cohabitation: up to 2 weeks
- Proof of pregnancy: vaginal plug or sperm in vaginal smear referred to as day 0 of pregnancy
- After successful mating each pregnant female was caged: individually shoebox cage with corncob bedding

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Samples of the dosing formulations taken from the 1st, 2nd and 7th week preparations were analyzed for homogeneity via HPLC-UV prior to using. The analytically determined concentrations were within 10% of the target concentrations.

Duration of treatment / exposure:

(P) Males: 2 weeks before mating, 1 week during mating, 2 weeks after mating (minimum of 35 days)
(P) Females: 2 weeks before mating, 1 week during mating, during gestation and lactation until post-partum day 4 (minimum of 46 days)

Frequency of treatment:

7 days/week

Dose / conc.:

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

Dose / conc.:

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

Dose / conc.:

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

No. of animals per sex per dose:

12 P males and 12 P females per tested concentration and per control

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Doses were selected by the sponsor based on the results of previous toxicity studies with the test material.

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly

BODY WEIGHT: Yes
- Time schedule for examinations: 1 day prior to treatment initiation and weekly thereafter

FOOD CONSUMPTION AND COMPOUND INTAKE: Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as gfood/kg body weight/day: No
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No

Oestrous cyclicity (parental animals):

The stage of the estrous cycle was determined with daily vaginal smears taken during mating period until evidence for mating was found.

Sperm parameters (parental animals):

Parameters examined in P male parental generations:
testis weight and epididymis weight, stages of spermatogenesis and interstitial testicular cell structure

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: no

PARAMETERS EXAMINED
The following parameters were examined in F1 offspring:
number and sex of pups, stillbirths, live births

GROSS EXAMINATION OF DEAD PUPS:
yes, for external abnormalities; possible cause of death was not determined for pups born or found dead.

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: All surviving animals, including those found dead or euthanized moribund
- Maternal animals: All surviving animals, including those found dead or euthanized moribund

GROSS NECROPSY
- Gross necropsy consisted of examination of the external body surface, all orifices, the cranial, thoracic, and peritoneal cavities and their contents.

HISTOPATHOLOGY / ORGAN WEIGHTS
- The tissues of livers, ovaries, testes and epididymides were prepared for microscopic examination and weighed, respectively.

Postmortem examinations (offspring):

The F1 animals were not subjected to postmortem examinations.

Statistics:

Calculation of means and standard deviations using Microsoft Excel; Systat 10 used for remaining statistical analysis. Analysis of data for homogeneity of variance using Levene's test. In case of homogeneous data, the data were further analyzed by one-way analysis of variance (ANOVA); in case of non-homogeneous data, Dunnett's test was performed for post-hoc comparisons. Mating and absolute pup-survival were analyzed using the Chi-Square test.

Reproductive indices:

Successful Mating: (# Successful Parturation / # Selected for Littering) x 100
% Pre-implantation loss = [(Total Corpora Lutea - Total Corpora Implants) / Total Corpora Lutea] x 100
% Post-implantation loss = [(Total Implants - Total Born) / Total Implants] x 100

Offspring viability indices:

% alive on day 0 = [(Total number of pups born - number of stillborn fetuses) / Total number of pups born] x 100
% alive on day 4 = (number alive on day 4 / number alive on day 0) x 100
% surviving = (number alive on day 4 / number alive on day 0) x 100

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

All signs observed (i.e. alopecia, red material around nose/eyes, forelimbs/gead scab, and ventral mass) were sporadically distributed among the groups and low in incidence.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, non-treatment-related

Description (incidence):

One control female (animal number 62) died during the first week of the study due to gavage trauma.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Body weight and body weight gain were similar across all groups with no observed treatment-related trends.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

Food consumption was not affected by treatment.

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Endocrine findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

Histopathological findings (i.e. degeneration of germinal epithelium in the testes and interstitial infiltration with mixed cells in the epididymides) were considered incidental and non-treatment related.

Histopathological findings: neoplastic:

no effects observed

Other effects:

no effects observed

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Key result

Dose descriptor:

NOAEL

Remarks:

reproductive

Effect level:

>= 750 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no adverse effects observed up to highest dose tested

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Critical effects observed:

no

Clinical signs:

not examined

Dermal irritation (if dermal study):

not examined

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Anogenital distance (AGD):

not examined

Nipple retention in male pups:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

Other effects:

not examined

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

not examined

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

>= 750 mg/kg bw/day

Based on:

test mat.

Sex:

not specified

Basis for effect level:

other: no adverse effects were observed up to the highest concentration

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Critical effects observed:

no

Key result

Reproductive effects observed:

no

Conclusions:

Based on these findings, the no-observed-adverse-effect level (NOAEL) for systemic and reproductive toxicity is equal to or greater than the highest dose tested 750 mg/kg bw/day.

Executive summary:

Test Item was formulated in deionized water (vehicle) and was administered as a solution by oral gavage at dose levels of 0 (vehicle control), 50, 250 or 750 mg/kg bw/day to 12 Sprague­ Dawley rats/sex/group for the assessment of reproductive and developmental toxicity. Doses were administered at a constant volume of 5 mL/kg bw for 2 weeks prior to mating, during the approximately 1-week mating period, through gestation and lactation until sacrifice, for a total of 5 weeks of dosing for males and approximately 7 weeks for females. Parental food consumption, body weights, body weight gain, reproductive performance, organ weights and histopathology were evaluated during the study, along with offspring body weight and survival.

 

No treatment-related clinical signs or deaths occurred during the study. Parental body weight, body weight gain and food consumption were unaffected by treatment.

 

No statistically significant differences in mean corpora lutea, implantation sites, litter size, total pups born or pups born alive on postnatal days 0 were detected among the groups. Pup survival was unaffected by treatment on postnatal day 0 and 4. Offspring body weight and growth were similar across all groups and unaffected by treatment.

 

Parental reproductive organ weights (ovaries, testes or epididymides) failed to reveal any treatment-related effect. Male liver weights and liver-to-body weight ratios were increased in a dose-related manner; however, statistical significance was not achieved. No evidence of histological changes was observed in the ovaries, testes or epididymides.

 

Based on these findings, the no-observed-adverse-effect level (NOAEL) for systemic and reproductive toxicity is equal to or greater than the highest dose tested 750 mg/kg bw/day.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

750 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The key study is GLP-compliant and of high quality (Klimisch score = 1).

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Test Item was formulated in deionized water (vehicle) and was administered as a solution by oral gavage at dose levels of 0 (vehicle control), 50, 250 or 750 mg/kg bw/day to 12 Sprague­ Dawley rats/sex/group for the assessment of reproductive and developmental toxicity in a study similar to OECD TG 421. Doses were administered at a constant volume of 5 mL/kg bw for 2 weeks prior to mating, during the approximately 1-week mating period, through gestation and lactation until sacrifice, for a total of 5 weeks of dosing for males and approximately 7 weeks for females. Parental food consumption, body weights, body weight gain, reproductive performance, organ weights and histopathology were evaluated during the study, along with offspring body weight and survival.

 

No treatment-related clinical signs or deaths occurred during the study. Parental body weight, body weight gain and food consumption were unaffected by treatment.

 

No statistically significant differences in mean corpora lutea, implantation sites, litter size, total pups born or pups born alive on postnatal days 0 were detected among the groups. Pup survival was unaffected by treatment on postnatal day 0 and 4. Offspring body weight and growth were similar across all groups and unaffected by treatment.

 

Parental reproductive organ weights (ovaries, testes or epididymides) failed to reveal any treatment-related effect. Male liver weights and liver-to-body weight ratios were increased in a dose-related manner; however, statistical significance was not achieved. No evidence of histological changes was observed in the ovaries, testes or epididymides.

 

Based on these findings, the no-observed-adverse-effect level (NOAEL) for systemic and reproductive toxicity is equal to or greater than the highest dose tested 750 mg/kg bw/day.

Effects on developmental toxicity

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Justification for classification or non-classification

Harmonised classification:

The substance has no harmonised classification for toxicity to reproduction according to the Regulation (EC) No. 1272/2008 (CLP). 

 

Self-classification:

Based on the available information, no self-classification is proposed according to the CLP or GHS.