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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

An OECD TG 473 in vitro test has been conducted to determine the possible clastogenicity of dilithium tetraborate using cultured human lymphocytes.  Both in the absence and presence of S9-mix, dilithium tetraborate did not induce any statistically significant and biologically relevant increase in the number of cells with chromosome aberrations in two independent experiments.

In an OECD TG 471 in vitro study, dilithium tetraborate induced dose related increases in tester strain TA100 (Salmonella typhimurium) in the absence and presence of S9-mix in two independent experiments (2.0 and 2.3-fold), respectively. The results in TA100 are therefore considered equivocal.

An OECD TG 490 in vitro study, was conducted to evaluate the mutagenic potential of Dilithium tetraborate by testing its ability to induce forward mutations at the thymidine kinase (TK) locus in L5178Y mouse lymphoma cells, either in the absence or presence of a metabolic system (S9-mix). Negative in vitro results for mutagenicity in mammalian cells were obtained for dilithium tetraborate.

Read-across to these results are proposed for the UVCB-Reaction products of boric acid and lithium hydroxide since at physiological pH, it will dissociate and release boric acid and lithium ions as a result of relevant transformation pathways. Variations in structure (trigonal vs tetrahedral) between the substances are not expected to lead to any changes to the results.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

In an OECD 471 Ames test a borderline positive response was observed in strain TA100 for the test material (dilithium tetraborate); however, a clear negative result was obtained in an OECD 473 cytogenicity test. For confirmation of genotoxicity status an OECD 490 Mouse Lymphoma Assay was conducted on dilithium tetraborate which was negative.
As outlined in Figure R.7.7-1 Flow chart of the mutagenicity testing strategy in the Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7a: Endpoint specific guidance, Version 6.0, July 2017, the substance is deemed negative for mutagenicity and no further testing is required.

Additional information

Justification for classification or non-classification