Fumes, silica

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1973

Report date:

1973

Materials and methods

Test guideline

Test guideline 1

Qualifier:

no guideline available

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Principles of method if other than guideline:

test material was administered to pregnant animals

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Silicon dioxide

EC Number:

231-545-4

EC Name:

Silicon dioxide

Cas Number:

7631-86-9

Molecular formula:

O2Si

IUPAC Name:

dioxosilane

Details on test material:

Syloid 244: CAS-Name: Silica gel, cryst.-free; CAS-No. 112926-00-8

Test animals

Species:

hamster, Syrian

Strain:

other: (outbred)

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: no data
- Age at study initiation: no data
- Weight at study initiation: no data
- Fasting period before study: no
- Housing: single
- Diet: ad libitum
- Water: ad libitum


ENVIRONMENTAL CONDITIONS
- Temperature (°C): no data
- Humidity (%): no data
- Photoperiod (hrs dark / hrs light): no data

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: water suspension

Analytical verification of doses or concentrations:

no

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1/1
- Length of cohabitation: no data
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy

Duration of treatment / exposure:

from day 6 to day 10 of gestation

Frequency of treatment:

1x/d

Duration of test:

day 14: sacrifice of dams by Caesarian section

No. of animals per sex per dose:

21 - 22 pregnant hamsters

Control animals:

yes, concurrent vehicle

other: pos. control receiving Aspirin (250 mg/kg bw)

Details on study design:

- Dose selection rationale: no data

Examinations

Maternal examinations:

BODY WEIGHT: Yes
- Time schedule for examinations: gestation day 0, 6, 8, 10, and 14


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: no data


POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 14
- Organs examined: in particular urogenital tract

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 resorptions: Yes
- Number of early resorptions: No data
- Number of late resorptions: No data

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: 1/3 per litter
- Skeletal examinations: Yes: 1/3 per litter
- Head examinations: No data

Statistics:

no data

Historical control data:

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)

Dose descriptor:

NOAEL

Remarks:

(Maximum dose tested)

Effect level:

1 600 mg/kg bw/day

Basis for effect level:

other: maternal toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Effect levels (fetuses)

Dose descriptor:

NOAEL

Remarks:

(maximum dose tested)

Effect level:

1 600 mg/kg bw/day

Basis for effect level:

other: teratogenicity

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

The administration of up to 1600 mg/kg (body weight)of the
test material to pregnant hamsters for 5 consecutive days
had no clearly discernible effect on nidation or on maternal
or fetal survival. The number of abnormalities seen in either 
soft or skeletal tissues of the test groups did not differ from
the number occuring spontaneously in the sham- treated controls.