Cordierite (Mg2[Al4O3(SiO3)5])

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Study period:

1974

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study was conducted using a method similar to OECD Testing Guideline 473 and meets acceptable scientific standards.

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 473 (In Vitro Mammalian Chromosome Aberration Test)

Deviations:

yes

Remarks:

Study performed without metabolic activation using a non-standard cell lines (WI-38 - human embryonic lung cultures)

GLP compliance:

no

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

Silicic acid, aluminum sodium salt

EC Number:

215-684-8

EC Name:

Silicic acid, aluminum sodium salt

Cas Number:

1344-00-9

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): FDA 71-45 (Sodium silicoaluminate)
- Physical state: Fine white powdered material
- Lot/batch No.: SR-1621

Method

Species / strain

Species / strain / cell type:

mammalian cell line, other: WI-38 - human embryonic lung cultures

Details on mammalian cell type (if applicable):

- Type and identity of media: Not provided
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes
- Periodically checked for karyotype stability: Not provided
- Periodically "cleansed" against high spontaneous background: Not provided

Metabolic activation:

without

Test concentrations with justification for top dose:

1, 10 and 100 µg/ml

Vehicle / solvent:

- Vehicle: 0.85 saline

Controls

Negative solvent / vehicle controls:

yes

Remarks:

Saline solution

Positive controls:

yes

Positive control substance:

triethylenemelamine

Remarks:

0.1 µg/ml

Details on test system and experimental conditions:

METHOD OF APPLICATION: in suspension

DURATION
- Exposure duration: 24 - 48 h

STAIN: acetic acid-orcein stain (20%)

NUMBER OF REPLICATIONS: 3 per concentration

NUMBER OF CELLS EVALUATED: 100 per concentration

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index

OTHER EXAMINATIONS:
- Determination of polyploidy

Evaluation criteria:

Evaluation of the genetic damage by identification of the aberrations (bridges, pseudochiasmata, multipolar cells, acentric fragments, etc) induced by the test substance.

Statistics:

Not provided

Results and discussion

Test results

Species / strain:

mammalian cell line, other: WI-38 - human embryonic lung cultures

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

250 µg/ml

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

Acentric fragments:
- Negative control: 2%
- 1 µg/ml: 0%
- 10 µg/ml: 1%
- 100 µg/ml: one cell with an acentric fragment and one cell with a bridge (non significant).
- Positive control: four cells with pulverization together with the other aberrations.

Remarks on result:

other: strain/cell type: WI-38 - human embryonic lung cultures

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

The test item was considered to be non-mutagenic under the conditions of the test.

Executive summary:

The in vitro cytogenicity in mammalian cells of the read-across substance sodium silicoaluminate branded as FDA 71-45 was determined according to a method similar to the OECD Guideline for Testing of chemicals 473. Chromosome aberrations were evaluated in WI-38 - human embryonic lung cultures without metabolic evaluation.

The in vitro mammalian chromosome aberration test was performed with concentrations of 1, 10 and 100 µg/ml in a saline solution at 0.85%. Anaphase preparations were made by growing the WI-38 cells in presence of the test item. Cells were then suspended in acetic acid-orcein stain (20%) and put in slides to be evaluated. Evaluation of the genetic damage was made by identification of the aberrations induced by the test item.

Cytotoxicity was observed at a concentration of 250 µg/ml. No significant numbers of aberration were observed for each tested concentration.

The test item was considered to be non-mutagenic under the conditions of the test.