Hydrothermal synthesis product of calcium oxide, quartz and water

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian germ cell study: cytogenicity / chromosome aberration

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

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 478 (Genetic Toxicology: Rodent Dominant Lethal Test)

GLP compliance:

no

Type of assay:

rodent dominant lethal assay

Test material

Test material information

Constituent 1

Reference substance name:

Silicic acid, calcium salt

EC Number:

215-710-8

EC Name:

Silicic acid, calcium salt

Cas Number:

1344-95-2

IUPAC Name:

Silicic acid, Calcium salt

Test material form:

solid

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: no data
- Age at study initiation: 10 - 12 weeks

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

- vehicle: 0.85 % saline
- Volume of the vehicle: no data
- Justification for choice of solvent/vehicle: no data
- Concentration of test material in vehicle: no data


MAXIMUM DOSE VOLUME APPLIED: no data

Duration of treatment / exposure:

single administration ("acute") and repeated administration (5 times, "subacute")

Frequency of treatment:

1x and 5x (1x/day)

Doses / concentrations

Remarks:

Doses / Concentrations:
150, 500 and 1500 mg/kg bw, suspended in 0.85 % saline, administered 1x/d (Test I), 5000 mg/kg bw (Test II)
Basis:

No. of animals per sex per dose:

10 males (treated) mated to virgin female rats (2 females/1 male)

Control animals:

yes, concurrent vehicle

yes, historical

Positive control(s):

triethylene melamine
- Route of administration: i.p.
- Doses / concentrations: 0.3 mg/kg bw

Examinations

Tissues and cell types examined:

Fertility index = No. pregnant females / No. mated
Total No. of implantations
Total number of corpora lutea
Preimplantation losses
see Report p. 132 - 135:
Dead implants
Females with one or more dead implants
Dead implants per total implants

Statistics:

Chi-square test, Armitage´s trend test, regression analyses, Freeman-Tukey transformation, t-test (Report p. 132 - 135)

Results and discussion

Test results

Key result

Sex:

male

Genotoxicity:

negative

Toxicity:

not specified

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

For single and repeated dosage of 15, 15, and 150 mg/kg bw (Report p. 80 - 99) as well as single and repeated dosage of 5000 mg/kg bw (Report p. 100 - 117),there was no dose-response and time-trend pattern of effects following the silicate treatment: The values calculated for reproduction parameters (see "Examinations" above) that related to the treated animals did not significantly vary from those obtained from the negative controls, whereas TEM caused a significant preimplantation loss and embryo resorption during the first five weeks.

Applicant's summary and conclusion

Conclusions:

Interpretation of results: negative