Registration Dossier

Diss Factsheets

Toxicological information

Developmental toxicity / teratogenicity

Currently viewing:

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: Comparable to guideline studies 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
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Deviations:
yes
Remarks:
(duration of treatment from day 6 to day 15 of gestation)
GLP compliance:
no
Limit test:
no

Test material

Constituent 1
Reference substance name:
Silicon dioxide
EC Number:
231-545-4
EC Name:
Silicon dioxide
Cas Number:
7631-86-9
IUPAC Name:
dioxosilane
Details on test material:
- Name of test material (as cited in study report): Syloid 244: CAS-Name: Silica gel, cryst.-free; CAS-No. 112926-00-8
- Analytical purity: no data

Test animals

Species:
mouse
Strain:
CD-1
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Fasting period before study: no
- Housing: single
- Diet: ad libitum
- Water: ad libitum

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
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy
Duration of treatment / exposure:
from day 6 to day 15 of gestation
Frequency of treatment:
daily
Duration of test:
gestation day 17: sacrifice of all dams by Caesarian section
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 13.4, 62.3, 289 and 1340 mg/kg bw/d
Basis:
actual ingested
No. of animals per sex per dose:
21 - 26 pregnant dams
Control animals:
yes
other: positive control dosed with Aspirin (150 mg/kg bw/d)
Details on study design:
- Dose selection rationale: no data

Examinations

Maternal examinations:
BODY WEIGHT: Yes
- Time schedule for examinations: gestation day 0, 6, 11, 15, and 17

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 17
- Organs examined: in particular urogenital tract

Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of resorptions: Yes
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: Yes

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:
Maternal toxic effects:no effects

Details on maternal toxic effects:
The administration of up to 1340 mg/kg bw/day of the test material to pregnant mice for 10 consecutive days had no clearly discernible effect on nidation or on maternal survival.

Effect levels (maternal animals)

Dose descriptor:
NOAEL
Effect level:
>= 1 340 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: maternal toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
The administration of up to 1340 mg/kg bw/day of the test material to pregnant mice for 10 consecutive days had no clearly discernible effect on fetal survival. The number of abnormalities seen in either soft or skeletal tissues of the test groups did not differ from the number occurring spontaneously in the sham-treated controls.

Effect levels (fetuses)

Dose descriptor:
NOAEL
Effect level:
>= 1 340 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: teratogenicity

Fetal abnormalities

Abnormalities:
not specified

Overall developmental toxicity

Developmental effects observed:
not specified

Applicant's summary and conclusion