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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro transformation study in mammalian cells
Remarks:
Type of genotoxicity: genome mutation
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study well documented, meets generally accepted scientific principles, acceptable for assessment.

Data source

Reference
Reference Type:
publication
Title:
Cytotoxic and transforming effects of silica particles with different surface properties in Syrian hamster embryo (SHE) cells.
Author:
Elias, Z., O. Poirot, et al.
Year:
2000
Bibliographic source:
Toxicol In Vitro.14(5): 409-22.

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
EU Method B.21 (In Vitro Mammalian Cell Transformation Test)
Principles of method if other than guideline:
Evaluation of cytotoxic and cell transforming effects of various crystalline (quartz, cristobalite) and amorphous forms of silica (biogenic, synthetic) in Syrian hamster embryo cells was performed.
GLP compliance:
not specified
Type of assay:
in vitro mammalian cell transformation assay

Test material

Constituent 1
Reference substance name:
Automatically generated during migration to IUCLID 6, no data available
IUPAC Name:
Automatically generated during migration to IUCLID 6, no data available
Details on test material:
- synthetic pyrogenic silica (Aerosil OX50)
- Other silicas tested also included:
- crystalline silica: quartz and cristobalite;
- amorphous silica: diatomacaeus earth

Method

Species / strain
Species / strain / cell type:
mammalian cell line, other: Syrian hamster embryo cells
Metabolic activation:
without
Test concentrations with justification for top dose:
3, 8, 25 and 30 microg/cm2 (estimated on the basis of figures in study report)
Vehicle / solvent:
sterile tridistilled water
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
no
True negative controls:
no
Positive controls:
no
Positive control substance:
other: 2158
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium
DURATION
- Preincubation period: 24 h
- Exposure duration: 7 days
- Expression time (cells in growth medium): -
- Selection time (if incubation with a selection agent): -
- Fixation time (start of exposure up to fixation or harvest of cells): 7 days
DETERMINATION OF CYTOTOXICITY
- Method: Inhibition of cell growth.
Evaluation criteria:
The criteria decribed by DiPaolo (Journal Natl Cancer Inst, 42, 867-876, 1969) and Pienta et al. (Short term tests for Chemical carcinogens, ed. H.F. Stick and R.H.C. San, Springer-Verlag, NY, p. 323-337, 1981) was used to define the colony as morphologically transformed
Statistics:
The relation between the transformation induced by a sample and the treatment concentrations was indicated by the significance of the correlation coefficient (r). No further information on statistical methods was given.

Results and discussion

Test results
Species / strain:
other: Syrian hamster ovarian cells
Metabolic activation:
not applicable
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
not examined
Untreated negative controls validity:
not specified
Positive controls validity:
not examined
Additional information on results:
Comparison to diacemateous earth and crystalline silica was made. Hydrophilic pyrogenic silica (Aerosil® OX50) was neither cytotoxic nor transforming whereas some quartz and cristobalite samples and 3 differant diatomaceous earths induced cytotoxicity and morphological colony transformation in a dose-dependent manner. Surface properties (distribution of silanol groups and trace amounts of iron) appeared to be important in the induction of cytotoxicity.
Remarks on result:
other: strain/cell type: Syrian hamster ovarian cells
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

Hydrophilic pyrogenic silica (Aerosil® OX50) was neither cytotoxic nor transforming.
Executive summary:

Elias et al. (2000) evaluated cytotoxic and cell transforming effects of various crystalline (quartz, cristobalite) and amorphous forms of silica (biogenic, synthetic) in Syrian hamster embryo cells. Hydrophilic pyrogenic silica (Aerosil® OX50) was neither cytotoxic nor transforming.