Ammonium tetrafluoroborate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro cytogenicity / micronucleus study

Type of information:

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

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Reverse mutation assay
No study on the ability of potassium tetrafluoroborate to induce gene mutations in prokaryotic cells was found. However, Article 13 of the REACH legislation states that, in case no appropriate animal studies are available for assessment, information should be generated whenever possible by means other than vertebrate animal tests, i. e. applying alternative methods such as in vitro tests, QSARs, grouping and read-across.
An Ames test with Salmonella typhimurium strains TA98, TA100, TA1535, TA1537 and TA1538 and Escherichia coli strain WP2uvrA was available for a structural analogue, tetrafluoroboric acid (42% aqueous solution) (Shimizu, 1985). The study was conducted according to the Guidelines of the Japanese Ministry of Labour. The strains were treated with test concentrations ranging from 1 to 5000 μg/plate, both in the presence and absence of metabolic activation. No increased number of revertants was observed in any case. Based on the results, the substance was concluded to give negative results in the Ames test.

Gene mutation assay
In a GLP compliant gene mutation test performed according to OECD guideline 476, potassium tetrafluoroborate was examined for its potential to induce gene mutations at the TK-locus of cultured mouse lymphoma L5178Y cells, in both the absence and the presence of a metabolic activation system (S9-mix) (TNO Triskelion BV, 2012). One test was conducted. In this test 6 duplicate cultures were treated for 24 hours and 4 hours in the absence and presence of S9-mix, respectively. The test substance was dissolved in dimethylsuphoxide (DMSO). The highest concentration tested and evaluated for mutagenicity was 10 mmol/L. The test substance was slightly toxic to the cells in the absence of S9 -mix. A slight decrease by 24% of the relative growth (RTG) was observed at the highest dose of 10 mmol/L. In the presence of S9 -mix no cytotoxicity was observed. In both the absence and presence of S9-mix no increase in mutant frequency was observed at any test substance concentration evaluated. All data were within the range of the negative control and the historical background. Methyl methanesulphonate (MMS) and 3-methylcholanthrene (MCA) were used as positive control substances in the absence and presence of the S9-mix, respectively; DMSO served as negative control. The negative controls were within historical background ranges and treatment with the positive control yielded the expected significant increase in mutant frequency compared to the negative controls. It is concluded that under the conditions used in this study, the test substance potassium tetrafluoroborate is not mutagenic at the TK-locus of mouse lymphoma L5178Y cells in both the absence and presence of metabolic activation (S9-mix).

Micronucleus test
In a GLP-compliant micronucleus test, performed according to OECD Guideline 487, potassium tetrafluoroborate was examined for its potential to induce micronuclei in cultured binucleated human lymphocytes, in both the absence and presence of a metabolic activation system (S9 -mix) (TNO Triskelion BV, 2012). Two independent in vitro micronucleus tests were conducted for which blood was obtained from two different donors. Dimethylsulfoxide (DMSO) was used as solvent for the test substance. Dose levels ranging from 2.5 to 1260 μg/mL were tested as final concentrations in the culture medium. Cytotoxicity was calculated from the Cytokinesis-Block Proliferation Index (CBPI). In the first test, in the presence and absence of metabolic activation (S9-mix) the treatment/recovery time was 4/20 hours (pulse treatment). In the second test, in the absence of metabolic activation, the treatment/recovery time was 20/28 hours (continuous treatment group). In the first test, in the presence of metabolic activation, a trend towards slightly decreased CBPI-values was observed at all dose levels. In the absence of metabolic activation, no cytotoxicity was observed. In the pulse treatment test, analysis of micronuclei formation was carried out at three dose levels (1260, 630 and 315 μg/mL), in the cultures of the solvent control and in the cultures of the positive controls. In the second test, no cytotoxicity was observed at any of the dose levels analysed. In the continuous treatment group, analysis of micronuclei formation was carried out in the cultures of three dose levels (1260, 1000 and 800 μg/mL) of the test substance, the cultures of the solvent control and the cultures of the positive controls. In both the first and the second test, the negative controls were within the historical data. Treatment with the positive controls, cyclophosphamide, vinblastine sulphate and mitomycin C, resulted in statistically significant increases in the numbers of binucleated cells containing micronuclei, when compared to the numbers observed in the cultures treated with the solvent control. This demonstrates the validity of the study. In both the first and second test, the test substance did not cause a significant increase in the number of binucleated cells containing micronuclei, at any of the dose levels analysed, when compared to the numbers found in the concurrent negative control. From the results obtained in the first and second in vitro micronucleus test it is concluded that, under the conditions used in this study, the test substance potassium tetrafluoroborate was not clastogenic and/or aneugenic to cultured human lymphocytes.

Short description of key information:
The substance gave negative results in the reverse mutation assay, the in vitro gene mutation assay, and the in vitro micronucleus test both with and without metabolic activation.

Endpoint Conclusion: No adverse effect observed (negative)

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 472 (Genetic Toxicology: Escherichia coli, Reverse Mutation Assay)

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

- Name of test material (as cited in study report): tetrafluoroboric acid
- Molecular formula (if other than submission substance): HBF4
- Analytical purity: 42%

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

True negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Conclusions:

Based on the available in vitro genotoxicity studies, the test substance does not need to be classified for genotoxicity according to Directive 67/548/EEC and according to the EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008

Reference 2

Endpoint:

in vitro gene mutation study in bacteria

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Endpoint conclusion

Endpoint conclusion:

no study available

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The inorganic substance has no structural alerts for mutagenecity.