N-(3-(trimethoxysilyl)propyl)ethylenediamine

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

The key study for toxicity to reproduction (Dow Corning Corporation, 2002b) found a NOAEL for reproductive effects (as well as parental systemic effects), in rats treated by gavage, of 500 mg/kg bw/day, the highest dose tested.

Link to relevant study records

Reference

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24.09.2001 to 06.09.2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

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

Principles of method if other than guideline:

Modified OECD 422 and USEPA Health Effects test guideline OPPTS 870.3650 (2000)

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc.
- Age at study initiation: At least 8 weeks
- Weight at study initiation: Males: 253-301 g; Females: 181-229 g
- Fasting period before study: None
- Housing: Individually housed in suspended wire-mesh cages. Pregnant females were moved into shoebox cages no later than three days prior to their expected delivery date
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: Five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25
- Humidity (%): 30-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 01.10.2001 To: 11.04.2002

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: The dosing formulations were prepared daily by adding an appropriate amount of test substance to a measured amount of vehicle (dried and de-acidified) under nitrogen atmosphere.

VEHICLE
- Justification for use and choice of vehicle (if other than water): Corn oil was dried and de-acidified to removal residual water before use as test substance hydrolyses in contact with moisture.
- Lot/batch no. (if required): 070K0127
- Purity: 100 %

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1:1
- Length of cohabitation: Until evidence of copulation occurred or up to 2 weeks
- Proof of pregnancy: vaginal plug or sperm in vaginal smear referred to as day 0 of pregnancy

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Concentration, homogeneity and stability of the test substance in the vehicle were verified by gas chromatopgraphy with a flame ionisation detection (FID). Concentration verification was conducted on a weekly basis.

Duration of treatment / exposure:

Males: 28 days (beginning 2 weeks prior to mating)
Toxicity phase female: 29 days (beginning 2 week prior to mating)
Reproductive phase females: 39-44 days (2 weeks prior to mating, throughout mating and pregnancy until day 3 postpartum

Frequency of treatment:

Daily (seven days/week)

Details on study schedule:

Not applicable to this screening study .

Dose / conc.:

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

Dose / conc.:

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

Dose / conc.:

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

No. of animals per sex per dose:

10/sex/dose (with females only used for of toxicity and reproductive phase groups)

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Based on the results of a dose range-finding study.

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily for morbidity, moribundity and mortality. General clinical observations were made at least once per day, approximately one hour after dosing.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Once before the first dosing and weekly thereafter.

BODY WEIGHT: Yes
- Time schedule for examinations: Individual body weights were recorded weekly beginning approximately one week prior to test substance administration, on the first day of dosing and just prior to scheduled necropsy.

FOOD CONSUMPTION: Individual food consumption was recorded weekly for female animals in the toxicity group for four weeks. Individual food consumption for the male animals and the reproductive group females were recorded during the first two weeks of treatment. Food consumption was not measured during the cohabitation period. Food consumption was measured for the reproductive group females throughout gestation until terminal sacrifice.

HAEMATOLOGY: Yes
- Time schedule for collection of blood: On the day of scheduled sacrifice
- Anaesthetic used for blood collection: Yes, ketamine HCl/Xylazine
- Animals fasted: Yes, overnight
- How many animals: All male and toxicity group females
- Parameters checked in table 1 were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: On the day of scheduled sacrifice
- Animals fasted: Yes
- How many animals: All male and toxicity group females
- Parameters checked in table 1 were examined.

FUNCTIONAL OBSERVATIONAL BATTERY (FOB): Yes
- Time schedule for examinations: Prior to the start of dosing and during the fourth week of the treatment. The assessments were conducted following the daily dose administration.
- Dose groups that were examined: All male and toxicity group females.
- Battery of functions tested: cageside observations, hand-held observations, open field observations, categorical observations, measurements/counts, motor activity.

Oestrous cyclicity (parental animals):

Apparently not investigated.

Sperm parameters (parental animals):

Parameters examined in male parental generation: testes weight, epididymis weight

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: No, all animals sacrificed on day 4 postpartum.

PARAMETERS EXAMINED
The following parameters were examined in offspring: number and sex of pups, stillbirths, live births, runts, presence of gross anomalies, weight gain, physical or behavioural abnormalities.

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

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: All surviving animals after 28 days of dosing.
- Maternal animals: All surviving animals on day 3 postpartum.
- Toxicity group females: All surviving animals after 29 days of dosing.

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.

HISTOPATHOLOGY / ORGAN WEIGHTS
The tissues indicated in Table 1 were prepared for microscopic examination and weighed, respectively.

Postmortem examinations (offspring):

SACRIFICE
- Postpartum day 4

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.

HISTOPATHOLOGY / ORGAN WEIGHTS
Not conducted.

Statistics:

All data analysis was carried out using SAS. In all comparisons, the family wise error rate was held at 5% (alpha=0.05). Prior to this analysis, an exploratory analysis was carried out on all variables tested. Bartlett's test was used to check for heterogeneity of variances and a Kolmogorov-smirnov test was used to test normality of the data. Parametric data was then tested using one-way Analysis of Variance (ANOVA) followed by Dunnett's Test (if significant). Non-parametric data were tested by Kruskal Wallis Test followed by Wilcoxon (if significant). For variables that had multiple measurements across time Repeated Measurement ANOVA was used to analyse the data. Categorical data were tested for equal proportions using the Fisher's Exact Test.

Statistically significant probabilities are reported at either the p≤0.05 or p≤0.01 levels.

Reproductive indices:

Fertility

Offspring viability indices:

Survival

Clinical signs:

effects observed, treatment-related

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Other effects:

not examined

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

CLINICAL SIGNS AND MORTALITY: One male in the 125 mg/kg bw/day dose group was found dead on study day 17 due to renal disease unrelated to treatment. There were two females in the reproductive groups that died due to dosing errors. All other animals survived to scheduled sacrifice. Clear perioral soiling was slightly more common in the high dose group. In the high dose groups there were increased nasal sounds, laboured breathing and/or soft squeaky vocalisation for one male and four toxicity and five reproductive group females. At 125 mg/kg bw/day, one toxicity group and one reproductive group female had increased nasal sounds. At 25 mg/kg bw/day, one toxicity group female exhibited soft squeaky vocalisation for three days of the study. The incidence of nasal sounds/squeaky vocalisation was noted in some animals and several times in others to a maximum of 18 days during the study. These findings were not observed in control rats.

BODY WEIGHT AND WEIGHT GAIN: Mean body weights in males and females in the 25, 125 and 500 mg/kg bw/day groups were comparable to the control group values throughout the study; no statistically significant differences were noted. Reductions (not statistically significant) in weekly body weight gain were observed in the 25 and 125 mg/kg bw/day group males during week 4. These reductions were not considered to be test substance-related since the difference did not occur in a dose-dependent manner and no reductions were noted in female body weight gains during this time period.

FOOD CONSUMPTION: There were no statistically significant differences in food consumption in any group.

HAEMATOLOGY: There were no treatment-related effects on haematology parameters. However, in the toxicity group females there was a statistically-significant increase in platelet counts compared to controls. The counts for the treated groups were within published historical control ranges, whereas controls in the present study were somewhat below those ranges. No biological/toxicological significance is attributed to treatment.

CLINICAL CHEMISTRY: There were no treatment-related effects on clinical chemistry. However, in females, there was a statistically significant decrease in the chloride value (1.9%) in the high dose group, and a slight decrease (1.4%) in sodium in the middle and high dose groups. There was no dose-response. Sodium values for all female groups, including controls, were within or slightly below published historical control ranges. Chloride values for all groups were slightly above published control ranges. There were no associated clinical or morphological findings, so the findings were not thought to be biologically or toxicologically significant.

FOB: Cage side observations: There were no treatment-related changes noted in unusual body movements, abnormal behaviour, posture or resistance to removal.
Handling observations: Palpebral closure, lacrimation, pupil size and reactivity, salivation, muscle tone, extensor thrust response and reactivity to handling were not affected by the treatment.
Open Field Observations: No differences were apparent between the control and treated groups in the open field observations.
Categorical Observations: No differences between control and treated groups when skin or hair coat, behaviour, respiration, muscle movements, eyes, urine or faeces, soiling, posture or general abnormalities were evaluated.
Measurements/counts: There was no effect on rectal temperature, hindlimb grip strength or landing foot splay assessments.
Motor activity: There were no effects on motor activity.

ORGAN WEIGHTS: There were no treatment-related effects on organ weights. There was no dose-response associated with a statistically-significant small increase in relative prostate weight in the 25 mg/kg bw/day group.

GROSS PATHOLOGY: There were no findings attributable to the test substance.

HISTOPATHOLOGY: There were no treatment-related findings.

REPRODUCTIVE FUNCTION: SPERM MEASURES (PARENTAL ANIMALS): No adverse effects.

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS): No adverse effects.

Key result

Dose descriptor:

NOAEL

Effect level:

>= 500 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No significant adverse effects on parent animals.

Critical effects observed:

no

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings:

not examined

VIABILITY (OFFSPRING): No adverse findings.

CLINICAL SIGNS (OFFSPRING): No adverse findings.

BODY WEIGHT (OFFSPRING): No adverse findings.

GROSS PATHOLOGY (OFFSPRING): No adverse findings.

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

>= 500 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No adverse effects on offspring were observed.

Critical effects observed:

no

Reproductive effects observed:

no

Lowest effective dose / conc.:

500 mg/kg bw/day

Treatment related:

no

Conclusions:

In an oral gavage study conducted to OECD 422 and to GLP (reliability score 1) the NOAEL for N-(3-(trimethoxysilyl)propyl)ethylenediamine relating to repeated dose (parental systemic) effects and to reproductive toxicity was at least 500 mg/kg bw/day, as no significant adverse effects were observed up to the highest dose of 500 mg/kg bw/day tested in rats.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

500 mg/kg bw/day

Study duration:

subacute

Species:

rat

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

The only available data for the reproductive toxicity endpoint is an oral study, OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test). In an oral gavage study in rats, conducted to OECD 422 and to GLP (reliability score 1), the NOAEL for the registered substance, relating to repeated dose (parental systemic) effects and reproductive toxicity, was at least 500 mg/kg bw/day, as no significant adverse effects were observed up to this, the highest dose tested.

Effects on developmental toxicity

Description of key information

The key study for developmental toxicity/teratogenicity (Charles River Laboratories, 2016) found a NOAEL for teratogenicity and developmental effects, in rats treated by gavage, of 750 mg/kg bw/day, the highest dose tested.

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

24.09.2001 to 06.09.2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD 422

Principles of method if other than guideline:

Modified OECD 422 and USEPA Health Effects test guideline OPPTS 870.3650 (2000)

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc.
- Age at study initiation: At least 8 weeks
- Weight at study initiation: Males: 253-301 g; Females: 181-229 g
- Fasting period before study: None
- Housing: Individually housed in suspended wire-mesh cages. Pregnant females were moved into shoebox cages no later than three days prior to their expected delivery date
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: Five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25
- Humidity (%): 30-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 01.10.2001 To: 11.04.2002

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: The dosing formulations were prepared daily by adding an appropriate amount of test substance to a measured amount of vehicle (dried and de-acidified) under nitrogen atmosphere.

VEHICLE
- Justification for use and choice of vehicle (if other than water): Corn oil was dried and de-acidified to removal residual water before use as test substance hydrolyses in contact with moisture.
- Lot/batch no. (if required): 070K0127
- Purity: 100 %

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Concentration, homogeneity and stability of the test substance in the vehicle were verified by gas chromatography with a flame ionisation detection (FID). Concentration verification was conducted on a weekly basis.

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1:1
- Length of cohabitation: Until evidence of copulation occurred or up to 2 weeks
- Proof of pregnancy: vaginal plug or sperm in vaginal smear referred to as day 0 of pregnancy

Duration of treatment / exposure:

Males: 28 days (beginning 2 weeks prior to mating)
Toxicity phase female: 29 days (beginning 2 week prior to mating)
Reproductive phase females: 39-44 days (2 weeks prior to mating, throughout mating and pregnancy until day 3 postpartum

Frequency of treatment:

Daily (seven days/week)

Duration of test:

Up to 44 days

Dose / conc.:

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

Dose / conc.:

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

Dose / conc.:

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

No. of animals per sex per dose:

10/sex/dose (with females only used for toxicity and reproductive phase groups)

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Based on findings of a dose range-finding study.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily for morbidity, moribundity and mortality. General clinical observations were made at least once per day, approximately one hour after dosing.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Once before the first dosing and weekly thereafter.

BODY WEIGHT: Yes
- Time schedule for examinations: Individual body weights were recorded weekly beginning approximately one week prior to test substance administration, on the first day of dosing and just prior to scheduled necropsy.

FOOD CONSUMPTION: Individual food consumption was recorded weekly for female animals in the toxicity group for four weeks. Individual food consumption for the male animals and the reproductive group females were recorded during the first two weeks of treatment. Food consumption was not measured during the cohabitation period. Food consumption was measured for the reproductive group females throughout gestation until terminal sacrifice.

HAEMATOLOGY: Yes
- Time schedule for collection of blood: On the day of scheduled sacrifice
- Anaesthetic used for blood collection: Yes, ketamine HCl/Xylazine
- Animals fasted: Yes, overnight
- How many animals: All male and toxicity group females
- Parameters checked in table 1 were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: On the day of scheduled sacrifice
- Animals fasted: Yes
- How many animals: All male and toxicity group females
- Parameters checked in table 1 were examined.

FUNCTIONAL OBSERVATIONAL BATTERY (FOB): Yes
- Time schedule for examinations: Prior to the start of dosing and during the fourth week of the treatment. The assessments were conducted following the daily dose administration.
- Dose groups that were examined: All male and toxicity group females.
- Battery of functions tested: cageside observations, hand-held observations, open field observations, categorical observations, measurements/counts, motor activity.

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: No
- Number of late resorptions: No

Fetal examinations:

SACRIFICE
- Postpartum day 4

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.

HISTOPATHOLOGY / ORGAN WEIGHTS
Not conducted.

Statistics:

All data analysis was carried out using SAS. In all comparisons, the family wise error rate was held at 5% (alpha=0.05). Prior to this analysis, an exploratory analysis was carried out on all variables tested. Bartlett's test was used to check for heterogeneity of variances and a Kolmogorov-smirnov test was used to test normality of the data. Parametric data was then tested using one-way Analysis of Variance (ANOVA) followed by Dunnett's Test (if significant). Non-parametric data were tested by Kruskal Wallis Test followed by Wilcoxon (if significant). For variables that had multiple measurements across time Repeated Measurement ANOVA was used to analyse the data. Categorical data were tested for equal proportions using the Fisher's Exact Test.

Statistically significant probabilities are reported at either the p≤0.05 or p≤0.01 levels.

Indices:

Viability and fertility

Details on maternal toxic effects:

Maternal toxic effects:no effects

Details on maternal toxic effects:
No significant adverse systemic effects in maternal animals.

Key result

Dose descriptor:

NOAEL

Effect level:

>= 500 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Abnormalities:

no effects observed

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
No abnormal behaviour or effects, including teratogenic, were observed in offspring.

Dose descriptor:

NOAEL

Effect level:

>= 500 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: No abnormal behaviour or effects, including teratogenic, were observed in offspring.

Abnormalities:

no effects observed

Developmental effects observed:

no

Conclusions:

In an oral gavage study conducted to OECD 422 and to GLP (reliability score 1) the NOAEL for N-(3-(trimethoxysilyl)propyl)ethylenediamine relating to repeated dose (systemic) effects and to developmental toxicity was at least 500 mg/kg bw/day, as no significant adverse effects were observed up to the highest dose of 500 mg/kg bw/day tested in rats.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

750 mg/kg bw/day

Species:

rat

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

In an oral gavage study in rats, conducted to OECD 414 and to GLP (reliability score 1), no evidence of maternal or developmental toxicity was noted at 100, 500, or 750 mg/kg bw/day. Test substance-related effects were limited to increased incidences of rales, clear material around the mouth, and/or salivation prior to dosing at 500 and 750 mg/kg bw/day. However, in the absence of any other signs of maternal toxicity at these dosage levels, these clinical observations were not considered to

be adverse. Based on these results, a dosage level of 750 mg/kg bw/day, the highest dosage level tested, was considered to be the NOAEL for maternal toxicity and embryo/fetal development when N-(3-(trimethoxysilyl)propyl)ethylenediamine was administered orally by gavage to rats.

Justification for classification or non-classification

Based on the available data the registered substance is not classified for effects on reproduction and development according to Regulation (EC) No 1272/2008/EC.