Silicate(2-), hexafluoro-, disodium, reaction products with lithium magnesium sodium silicate

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:

experimental study

Adequacy of study:

key study

Study period:

17/02/2010 to 24/06/2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test carried out by GLP compliant laboratory to recognised validated methods by trained personnel

Justification for type of information:

See Document "Laponite Analog justification-BL_6_30_2020.pdf" in Section 13.2 - Toxicokinetic assessment for Synthetic fluorohectorites for justification of read-across.

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

Silicic acid, lithium magnesium sodium salt

EC Number:

258-476-2

EC Name:

Silicic acid, lithium magnesium sodium salt

Cas Number:

53320-86-8

Molecular formula:

Na0.7[Li0.3Mg5.5Si8O20(OH)4]

IUPAC Name:

Synthetic hectorite

Details on test material:

This test substance, which is Laponite Type 2 is a "read-across" for Laponite Type 1 (EC 285-349-9), their structures being essentially identical with the exception of some fluoride ionic substitution for -OH within the clay lattice. Both materials exhibit the very similar physico-chemical behaviour. They both disperse in water to form a colloidal suspension rather than a solution. The colloidal suspension is clear giving the appearance of a solution. Neither form dissolves as such. Any hydrolysis resulting in degradation products is pH dependent and is described in section 5.1.2 Hydrolysis. No solubility and no hydrolysis is observed at neutral pH.

Method

Species / strain

Species / strain / cell type:

lymphocytes: human

Metabolic activation:

with and without

Test concentrations with justification for top dose:

The dose range for the Preliminary Toxicity Test was 9.77 to 2500 μg/ml. The maximum dose was the maximum practical dose level.

Results and discussion

Test results

Species / strain:

lymphocytes:

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: negative as tested

Remarks:

The test material did not induce any statistically significant increases in the frequency of cells with chromosome aberrations in either the absence or presence of a liver enzyme metabolising system. The test material was therefore considered to be non-clastogenic to human lymphocytes in vitro.

Applicant's summary and conclusion

Conclusions:

The test material did not induce any statistically significant increases in the frequency of cells with chromosome aberrations in either the absence or presence of a liver enzyme metabolising system. The test material was therefore considered to be non-clastogenic to human lymphocytes in vitro.