Trisodium nitrilotriacetate

Toxicity to reproduction

Administrative data

Endpoint:

two-generation reproductive toxicity

Remarks:

based on test type (migrated information)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: meets generally acceptable scientific standards, well documented and accepted for assessment

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1971

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)

Deviations:

not specified

Principles of method if other than guideline:

2-generation study in rats as part of a combined Reproduction and Teratology Studies

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Trisodium nitrilotriacetate

EC Number:

225-768-6

EC Name:

Trisodium nitrilotriacetate

Cas Number:

5064-31-3

Molecular formula:

C6H9NO6.3Na

IUPAC Name:

trisodium 2-[bis(carboxylatomethyl)amino]acetate

Details on test material:

- Name of test material (as cited in study report): Trisodium nitrilotriacetate
- Substance type: pure substance
- purity: not further specified

Test animals

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
Rat study
- Charles River CD rats
- Housing: caged individually
- Diet (e.g. ad libitum): ground Purina Chow ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 8 weeks (after weaning)

ENVIRONMENTAL CONDITIONS
Carefully controlled environment

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Mixing appropriate amounts with (Type of food): ground Purina Chow

Details on mating procedure:

Parent rats (F0) were bred three times to bear the generations F1a, F1b and F1c.
The F1a generation was discarded at weaning.
The F1c generation was used for teratological studies (see chapter 7.8.2 Developmental toxicity / teratogenicity).
The F1b generation were bred twice to bear the generations F2a and F2b.
The F2a generation was discarded at weaning.
The F2b generation was used for teratological studies (see chapter 7.8.2 Developmental toxicity / teratogenicity).

No further specification of the mating procedure.
Day of conception (day 0) was determined by vaginal smears.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

NTA had been mixed to ground Purina Chow to yield the target concentrations
For each generation, records of individual weekly feed consumption and body-weight gain were kept during the first 8 wk from weaning. Afterwards, the parent rats were weighed at the beginning of each mating phase and no records of feed consumption were kept.

Duration of treatment / exposure:

Continuously throughout two generations.

Frequency of treatment:

Continously feeding

Details on study schedule:

The original parent rats (F0) were bred three times to bear the generations F1a, F1b and F1c.
The F1a generation was discarded at weaning.
The F1c generation was used for teratological studies (see chapter 7.8.2 Developmental toxicity / teratogenicity).
The F1b generation were bred twice to bear the generations F2a and F2b.
The F2a generation was discarded at weaning.
The F2b generation was used for teratological studies (see chapter 7.8.2 Developmental toxicity / teratogenicity).

No detailed description of mating and age of rats.

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 0.1 and 0.5 %
Basis:
nominal conc.
approximately 90 and 450 mg/kg bw/day for adult female rats

No. of animals per sex per dose:

20

Control animals:

yes, plain diet

Details on study design:

- Dose selection rationale: Dose levels had been chosen from previous subacute and long-term studies, from which the lower level had been reported to be without any effect, whereas the 0.5% level had been reported to produce some mild toxicity (not further specified).

Positive control:

no

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: No data

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: weekly feed consumption and body weight gain during the first 8 weeks from weaning

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean weekly diet consumption calculated as g food and feed efficiency (%): Yes
Feed efficiency = body-weight gain/feed consumed × 10
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

Oestrous cyclicity (parental animals):

not determined

Sperm parameters (parental animals):

not determined

Litter observations:

STANDARDISATION OF LITTERS
- All live-born litters were counted at birth and again 4 days later, when the pups were weighed and their sex determined.
- Maximum of 8 pups/litter (4/sex/litter as nearly as possible); excess pups were killed and discarded on day 4.

PARAMETERS EXAMINED
The following parameters were examined in [F1a / F1b / F2a] offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, weight gain, lactation index, average weaning weight of pups per sex

GROSS EXAMINATION OF DEAD PUPS:
no; possible cause of death was not determined for pups born or found dead.

Postmortem examinations (parental animals):

SACRIFICE
- No post mortem examinations of parental animals

GROSS NECROPSY
- No gross necropsy of parental animals

HISTOPATHOLOGY / ORGAN WEIGTHS
No microscopic examination of parental animals

Postmortem examinations (offspring):

SACRIFICE
- No post mortem examinations of animals (exept for teratogenicity study, see 7.8.2)

GROSS NECROPSY
- No gross necropsy

HISTOPATHOLOGY / ORGAN WEIGTHS
No microscopic examination (exept for teratogenicity study, see 7.8.2)

Statistics:

Significance test, analysis of variance, not further specified

Reproductive indices:

Conception in %

Offspring viability indices:

Average no. born alive / litter
Average no. alive 4 days post partum
Average no. weaned / litter
lactation index = no. of pups weaned/no. alive at 4 days after litters reduced × 100
average weaning weight of pups per sex

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality:

not specified

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

A slight, but statistically significant, decrease in body weight gain was observed in high-dose females only, fed continuously, as compared to controls.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

A slight, but statistically significant, decrease in food consumption was observed in high-dose males only, fed continuously, as compared to controls.

Food efficiency:

effects observed, treatment-related

Description (incidence and severity):

A slight, but statistically significant, decrease in food efficacy was observed in mid-dose males only, fed continuously, as compared only to groups fed during gestation days 6 - 15. It is believed that this effect iwas probably due mostly to a reduced palatability of the feed.

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Endocrine findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Description (incidence and severity):

no significant differences in the conception rate during the specific phases of the study and no significant differences in the measures of fertility

Details on results (P0)

BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)
Mean total food consumption (determined by week 8) at the high dietary level (0.5% Na3NTA) was somewhat less than in the control and in the low dietary level (0.1% Na3NTA) group in both sexes but statistically significantly different only for the males. Mean body weight gain in male and female rats was slightly reduced for the high dietary level (0.5 %) in comparison to either controls or to the 0.1% group, statistically significantly different, however only for females. A slight, but statistically significant, decrease in food efficacy was observed in mid-dose males only, fed continuously, as compared only to groups fed during gestation days 6 - 15. It is believed that this effect was probably due mostly to a reduced palatability of the feed.

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
No significant differences in the conception rate during the specific phases of the study and no significant differences in the measures of fertility.

Effect levels (P0)

1

Dose descriptor:

NOAEL

Remarks:

reproduction

Effect level:

450 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: overall effects

2

Dose descriptor:

NOEL

Remarks:

systemic

Effect level:

90 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: overall effect

3

Dose descriptor:

LOAEL

Remarks:

systemic

Effect level:

450 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: depressed body weight gain

Target system / organ toxicity (P0)

Critical effects observed:

no

Results: P1 (second parental generation)

General toxicity (P1)

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality:

not specified

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

A slight, but statistically significant, decrease in body weight gain was observed only in males exposed in-utero from the highest dose group fed continuously as compared to controls and as compared to the high dose group fed during gestation days 6 thru 15.

Food consumption and compound intake (if feeding study):

effects observed, non-treatment-related

Description (incidence and severity):

A slight, but statistically significant, decrease in food consumption was observed only in males exposed in-utero from the low dose group fed during gestation days 6 thru 15 as compared to controls and the high dose group fed during gestation days 6 thru 15. The lack of dose-response suggests this is probably not treatment related.

Food efficiency:

effects observed, treatment-related

Description (incidence and severity):

A slight, but statistically significant, decrease in food efficacy was observed only in females exposed in-utero from the highest dose group fed continuously as compared to the groups fed only during gestation days 6 - 15.

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Endocrine findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Reproductive function / performance (P1)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Details on results (P1)

BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)
A slight, but statistically significant, decrease in body weight gain was observed only in males exposed in-utero from the highest dose group fed continuously as compared to controls and as compared to the high dose group fed during gestation days 6 thru 15. A slight, but statistically significant, decrease in food consumption was observed only in males exposed in-utero from the low dose group fed during gestation days 6 thru 15 as compared to controls and the high dose group fed during gestation days 6 thru 15. The lack of dose-response suggests this is probably not treatment related. A slight, but statistically significant, decrease in food efficacy was observed only in females exposed in-utero from the highest dose group fed continuously as compared to the groups fed only during gestation days 6 - 15.

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
No significant differences in the conception rate during the specific phases of the study and no significant differences in the measures of fertility.

Effect levels (P1)

1

Dose descriptor:

NOAEL

Remarks:

reproduction

Effect level:

450 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

exposed in-utero

Sex:

male/female

Basis for effect level:

other: overall effects

2

Dose descriptor:

NOEL

Remarks:

systemic

Effect level:

90 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

exposed in-utero

Sex:

male/female

Basis for effect level:

other: overall effects

3

Dose descriptor:

LOAEL

Remarks:

systemic

Effect level:

450 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

exposed in-utero

Sex:

male/female

Basis for effect level:

other: depressed body weight gain

Target system / organ toxicity (P1)

Critical effects observed:

no

Results: F1 generation

General toxicity (F1)

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality / viability:

not specified

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

A slight, but statistically significant, decrease in body weight gain was observed only in males exposed in-utero from the highest dose group fed continuously as compared to controls and as compared to the high dose group fed during gestation days 6 thru 15.

Food consumption and compound intake (if feeding study):

effects observed, non-treatment-related

Description (incidence and severity):

A slight, but statistically significant, decrease in food consumption was observed only in males exposed in-utero from the low dose group fed during gestation days 6 thru 15 as compared to controls and the high dose group fed during gestation days 6 thru 15. The lack of dose-response suggests this is probably not treatment related.

Food efficiency:

effects observed, treatment-related

Description (incidence and severity):

A slight, but statistically significant, decrease in food efficacy was observed only in females exposed in-utero from the highest dose group fed continuously as compared to the groups fed only during gestation days 6 - 15.

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Sexual maturation:

not specified

Anogenital distance (AGD):

not specified

Nipple retention in male pups:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Histopathological findings:

not specified

Other effects:

not specified

Developmental neurotoxicity (F1)

Behaviour (functional findings):

not specified

Developmental immunotoxicity (F1)

Developmental immunotoxicity:

not specified

Details on results (F1)

BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)
A slight, but statistically significant, decrease in body weight gain was observed only in males exposed in-utero from the highest dose group fed continuously as compared to controls and as compared to the high dose group fed during gestation days 6 thru 15. A slight, but statistically significant, decrease in food consumption was observed only in males exposed in-utero from the low dose group fed during gestation days 6 thru 15 as compared to controls and the high dose group fed during gestation days 6 thru 15. The lack of dose-response suggests this is probably not treatment related. A slight, but statistically significant, decrease in food efficacy was observed only in females exposed in-utero from the highest dose group fed continuously as compared to the groups fed only during gestation days 6 - 15.

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
No significant differences in the conception rate during the specific phases of the study and no significant differences in the measures of fertility.

Effect levels (F1)

1

Dose descriptor:

NOAEL

Generation:

F1b

Effect level:

450 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

exposed in-utero

Sex:

male/female

Basis for effect level:

other: overall effects

2

Dose descriptor:

NOEL

Generation:

F1b

Effect level:

90 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

exposed in-utero

Sex:

male/female

Basis for effect level:

other: overall effects

3

Dose descriptor:

LOAEL

Generation:

F1b

Effect level:

450 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

exposed in-utero

Sex:

male/female

Basis for effect level:

other: depressed body weight gain

Target system / organ toxicity (F1)

Critical effects observed:

no

Overall reproductive toxicity

Reproductive effects observed:

no

Any other information on results incl. tables

Group	Treatment
1	F0, F2a, Control Diet
2	F0, F2a, Control Diet + 0.1% Na3NTA Continuously
3	F0, F2a, Control Diet + 0.5% Na3NTA Continuously
4	F0, F2a, Control Diet + 0.1% Na3NTA GD 6 - 15
5	F0, F2a, Control Diet + 0.5% Na3NTA GD 6 – 15
6	F1b, F2b, Control Diet
7	F1b, F2b, Control Diet + 0.1% Na3NTA Continuously
8	F1b, F2b, Control Diet + 0.5% Na3NTA Continuously
9	F1b, F2b, Control Diet + 0.1% Na3NTA GD 6 - 15
10	F1b, F2b, Control Diet + 0.5% Na3NTA GD 6 – 15
11	F1c, Control Diet
12	F1c, Control Diet + 0.1% Na3NTA Continuously
13	F1c, Control Diet + 0.5% Na3NTA Continuously
14	F1c, Control Diet + 0.1% Na3NTA GD 6 - 15
15	F1c, Control Diet + 0.5% Na3NTA GD 6 – 15

8-wk F0 Body Weight Gain

Group	Body Weight Gain (g) - Males	Body Weight Gain (g) - Females
F0, 1	359	205
F0, 2	356	200
F0, 3	335	188^3
F0, 4	352	200
F0, 5	358	206

³  Significantly different (P ≤ 0.05) from Group 1 and Group 5.

 

8-wk F0 Food Consumption

Group	Food Consumption (g) - Males	Food Consumption (g) - Females
F0, 1	1261	943
F0, 2	1285	926
F0, 3	1191^4	891
F0, 4	1210	925
F0, 5	1227	942

⁴  Significantly different (P ≤ 0.05) from Group 2.

 

8-wk F0 Feeding Efficiency¹

Group	Feeding Efficiency (g) - Males	Feeding Efficiency (g) - Females
F0, 1	28.5	21.7
F0, 2	27.7^2	21.5
F0, 3	28.2	21.2
F0, 4	29.1	21.6
F0, 5	29.2	21.9

¹  Body weight gained/Food consumed X 100.

²  Significantly different (P ≤ 0.05) from Group 4 and Group 5.

8-wk F1b Body Weight Gain (in-utero Exposure Only)

Group	Body Weight Gain (g) - Males	Body Weight Gain (g) - Females
F1b, 6	322.3	137.2
F1b, 7	311.1	141.1
F1b, 8	284.3^2	132.8
F1b, 9	301.1	143.7
F1b, 10	320.6	149.9

²  Significantly different (P ≤ 0.05) from Group 6 and Group 10.

 

8-wk F1b Food Consumption (in-utero Exposure Only)

Group	Food Consumption (g) - Males	Food Consumption (g) - Females
F1b, 6	1462.5	955.6
F1b, 7	1405.1	1002.1
F1b, 8	1397.9	1018.2
F1b, 9	1362.4^3	955.6
F1b, 10	1462.3	1009.0

³  Significantly different (P ≤ 0.05) from Group 6 and Group 10

 

8-wk F1b Feeding Efficiency¹(in-utero Exposure Only)

Group	Feeding Efficiency (g) - Males	Feeding Efficiency (g) - Females
F1b, 6	22.3	14.5
F1b, 7	22.3	14.2
F1b, 8	20.7	13.4^4
F1b, 9	22.4	15.0
F1b, 10	22.1	14.7

¹  Body weight gained/Food consumed X 100.

⁴  Significantly different (P ≤ 0.05) from Group 9 and Group 10.

F0-Generation to produce F1a

	Group 1	Group 2	Group 3	Group 4	Group 5
Females paired	25	25	24	25	25
Females pregnant	24	24	24	21	24
Percent pregnant^1	96	96	100	84	95

¹  Fertility Index

 

F0-Generation to produce F1b

	Group 6	Group 7	Group 8	Group 9	Group 10
Females paired	20	20	20	20	20
Females pregnant	19	19	19	16	18
Percent pregnant^1	95	95	95	80	90

¹  Fertility Index

F0-Generation to produce F1c

F1c Group:	11		12		13		14		15
Days:	13	21	13	21	13	21	13	21	13	21
Females paired	10	10	10	10	10	10	10	10	10	10
Females pregnant	7	6	6	5	9	8	8	5	8	7
Percent pregnant^1	70	60	60	50	90	80	80	50	80	70

F1b-Generation to produce F2a

	F2a Group 1	F2a Group 2	F2a Group 3	F2a Group 4	F2a Group 5
Females paired	24	25	22	23	24
Females pregnant	22	23	19	23	22
Percent pregnant^1	92	92	86	100	92

¹  Fertility Index

F1b-Generation to produce F2b

F2b Group:	6		7		8		9		10
Days:	13	21	13	21	13	21	13	21	13	21
Females paired	11	11	11	11	10	10	10	10	10	12
Females pregnant	9	10	10	9	7	10	10	9	7	8
Percent pregnant^1	82	91	91	82	70	100	100	90	70	67

¹  Fertility Index

Applicant's summary and conclusion

Conclusions:

No significant effects on reproduction at 450 mg/kg/d.

Executive summary:

In a two-generation reproduction study Na3NTA was administered to 20 Sprague Dawley rats/sex/dose in dietary concentrations of 0, 0.1% and 0.5% (resp. daily intake for adult female rats approximately 90 and 450 mg/kg/d).

There were no significant differences in food efficiency. With respect to reproductive performance there were no significant differences in the conception rate during the specific phases of the study and no significant differences in the measures of fertility and lactation in terms of average numbers of live-borns per litter, live pups on p.n. day 4, average number of weaned pups per culled litter and in the lactation index. Body weights of the new-borns were not reported. Offspring weaning weights were reduced at the 0.5% level in both sexes, an effect observed in litters of the first breeding trials and statistically significant for the F1 generation only, but not consistent across successive breedings and/or across generations.

No examination of effects on reproductive parameters, testes weights or morphology, epididymal sperm counts, motility, or morphology, daily sperm production, efficiency of daily sperm production, or prostate or dorsal prostate weights or histopathology was performed.

The only effect of Na3NTA on rats in this study was some growth depression in both adult and weanling animals fed the 0 .5% level continuously. This effect was probably due mostly to a reduced palatability of the feed, since no such depression was seen in the weights of foetuses removed by Caesarean-section or in the weights of 4-day-old liveborn animals.

The study shows that Na3NTA, even at highly exaggerated levels, causes no deleterious effects on reproduction in rats.

This study meets generally acceptable scientific standards, is sufficiently documented and accepted for assessment.