Reaction mass of Limestone and dicalcium 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:

key study

Reliability:

2 (reliable with restrictions)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1974

Report date:

1974

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Calcium oxide

EC Number:

215-138-9

EC Name:

Calcium oxide

Cas Number:

1305-78-8

IUPAC Name:

oxocalcium

Details on test material:

- Name of test material (as cited in study report): FDA 73-41 (calcium oxide)
- Physical state: solid
No further details are given.

Test animals

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Housing: Rats were housed individually in mesh bottom cages.
- Diet: ad libitum
- Water: ad libitum; tap water
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 - 27
- Humidity (%): 64 - 78
No further details are given.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

no detailed data given

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

no detailed data given

Details on mating procedure:

The female rats were mated with young adult males.
- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1/1; one male was not permitted to impregnate more than one female per group.
- Length of cohabitation: no data
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy
No further details are given.

Duration of treatment / exposure:

Beginning on day 6 and continuing through day 15 of gestation, the females were dosed with the indicated dosages.

Frequency of treatment:

Once daily

Duration of test:

Until day 20 of pregnancy

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
6.8 mg/kg
Basis:
nominal in water

Doses / concentrations 2

Remarks:

Doses / Concentrations:
31.5 mg/kg
Basis:
nominal in water

Doses / concentrations 3

Remarks:

Doses / Concentrations:
146.5 mg/kg
Basis:
nominal in water

Doses / concentrations 4

Remarks:

Doses / Concentrations:
680 mg/kg
Basis:
nominal in water

No. of animals per sex per dose:

mated: 21 to 22 rats
pregnant: 19 to 20 rats

Control animals:

yes

yes, sham-exposed

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: All animals were observed daily for appearance and behaviour.
BODY WEIGHT: Yes
- Time schedule for examinations: Average body weight was determined on days 0, 6, 11, 15 and 20 of gestation.
FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes; however, compound intake occurred via gavave.
- Time schedule: All animals were observed daily with particular attention to food consumption and weight.
WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data; not applicable
POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: The urogential tract of each dam was examined in detail for anatomical normality.

Ovaries and uterine content:

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

Fetal examinations:

- External examinations: Yes
- Soft tissue examinations: Yes
- Skeletal examinations: Yes
- Head examinations: Yes

Statistics:

no data given

Indices:

no data given

Historical control data:

no data given

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:no effects

Details on maternal toxic effects:
Administration of up to 680 mg/kg bw/d of CaO to pregnant rats for 10 consecutive days had no clearly discernible effect on maternal survival.

Effect levels (maternal animals)

Dose descriptor:

NOAEL

Effect level:

680 mg/kg bw/day

Basis for effect level:

other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
Administration of up to 680 mg/kg bw/d of CaO to pregnant rats for 10 consecutive days had no clearly discernible effect on foetal survival. The number of abnormalities seen in either soft or skeletal tissues of test groups did not differ from the number occuring sponaneously in sham-treated controls.

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Administration of up to 680 mg/kg (body weight) of the test material to pregnant rats for 10 consecutive days had no clearly discernible effect on nidation or on maternal or foetal survival. The number of abnormalities seen in either soft or skeletal tissues of test groups did not differ from the number occuring spontaneously in sham-treated controls.