Slags, elec. furnace smelting, iron silicate

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:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well-documented study report; comparable to guideline study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1973

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

yes

Remarks:

exposure ended 11 days before Caesarean section: guideline 1 day

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

sodium silico-aluminate

IUPAC Name:

sodium silico-aluminate

Details on test material:

FDA substance 71-45.
No details presented.

Test animals

Species:

rabbit

Strain:

Dutch

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: no data
- Age at study initiation: adult
- Weight at study initiation: ca 3.1 kg
- Fasting period before study: no data
- Housing: individually in mesh bottom cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): controlled
- Humidity (%): controlled
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): no data

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

No details

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

- Impregnation procedure: artificial insemination

Duration of treatment / exposure:

Days 6-18 of gestation

Frequency of treatment:

Daily

Doses / concentrations

Remarks:

Doses / Concentrations:
16.0, 74.3, 345.0, 1600.0 mg/kg
Basis:
nominal conc.

No. of animals per sex per dose:

16.0 mg/kg: 17 rabbits, 74.3 mg/kg: 15 rabbits, 345.0 mg/kg: 15 rabbits; 1600.0 mg/kg: 23 rabbits. Controls 11 and and positive controls 18/group.

Control animals:

yes, sham-exposed

Details on study design:

Positive control 2.5 mg/kg of 6-aminonicotinamide

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: No data

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: days 0, 6, 8, 12, 18 and 29 of gestation

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes (observations, no calculations)

POST-MORTEM EXAMINATIONS: No data
- Sacrifice on gestation day 29

Ovaries and uterine content:

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

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: all per litter
- Skeletal examinations: Yes: all per litter

Statistics:

No data

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:no effects

Effect levels (maternal animals)

1

Dose descriptor:

NOAEL

Effect level:

1 600 mg/kg bw/day

Basis for effect level:

other: maternal toxicity

2

Dose descriptor:

NOAEL

Effect level:

1 600 mg/kg bw/day

Basis for effect level:

other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Maternal exposure of rabbits to Na-Al-silicate during days 6-18 of pregnancy did not cause any signs of teratogenicity or maternal toxicity even at the highest dose of 1600 mg/kg bw.

Executive summary:

The teratogenic effects of Na-Al-silicate were studied in rabbits (FDA 1973). Maternal exposure of rabbits to Na-Al-silicate during days 6-18 of pregnancy did not cause any signs of teratogenicity or maternal toxicity even at the highest dose of 1600 mg/kg bw.