Registration Dossier

Toxicological information

Genetic toxicity: in vivo

Currently viewing:

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
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 475 (Mammalian Bone Marrow Chromosome Aberration Test)
GLP compliance:
no
Type of assay:
chromosome aberration assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: nanoform, no surface treatment
Details on test material:
Silica gel; CAS-No. 7631-86-9; EINECS-No. 231-545-4; BET: 340 - 390 m2/g
Specific details on test material used for the study:
synthetic amorphous silicon dioxide Syloid 244

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male

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
Details on exposure:
3 time points: sampling at 6, 24, and 48 h in the single-dose study
1 time point: sampling at 6 h after the last dose in the repeated-dose study

Colcemide (4 mg/kg bw i.p) was given 2 h prior to kill.
Duration of treatment / exposure:
single administration (acute) and repeated administration (5 times, subacute)
Frequency of treatment:
1x, and 5x(1x/d)
Doses / concentrationsopen allclose all
Dose / conc.:
1.4 mg/kg bw/day (actual dose received)
Dose / conc.:
14 mg/kg bw/day (actual dose received)
Dose / conc.:
140 mg/kg bw/day (actual dose received)
Dose / conc.:
500 mg/kg bw/day (actual dose received)
Dose / conc.:
5 000 mg/kg bw/day (nominal)
No. of animals per sex per dose:
5; but 3 as vehicle control
Control animals:
yes, concurrent vehicle
Positive control(s):
triethylenemelamine
- Route of administration: i.p.
- Doses / concentrations: 0.3 mg/kg bw

Examinations

Tissues and cell types examined:
bone-marrow cells

Results and discussion

Test results
Sex:
male
Genotoxicity:
negative
Toxicity:
not specified
Vehicle controls validity:
valid
Positive controls validity:
valid

Applicant's summary and conclusion

Conclusions:
synthetic amorphous silicon dioxide Syloid 244 was negativein in in vivo chromosome aberration test.
Executive summary:

An in vivo chromosome aberration test similar to OECD 475 was conducted with synthetic amorphous silicon dioxide Syloid 244