Registration Dossier

Administrative data

Key value for chemical safety assessment

Additional information

A number of in vitro tests using bacterial strains (Ames test) and yeast, with and without metabolic activation, have been performed. Tetrabromobisphenol A has produced consistently negative results. Similarly, in a well-conducted chromosomal aberration study using human peripheral lymphocytes, tetrabromobisphenol A tested negative.

Overall, in view of the clearly negative in vitro studies, and no structural indications for any genotoxic potential, there are no concerns for genotoxicity.

Short description of key information:
Four in vitro Ames studies are available for this substance.
An in vitro chromosome aberration study is available for this substance.

A waiver is requested from peformanbce of a second in vitro study in mammalian cells:
REACH Guidance, Chapter R.7A, states that “… it may be possible to omit the second in vitro study in mammalian cells, i.e., if it can be demonstrated that this mammalian cell test will not provide any further useful information about the potential in vivo mutagenicity of the substance, then it does not need to be conducted” (page 390). TBBPA undergoes extensive first-pass metabolism (conjugation with glucuronide (primary) and sulphate) such that negligible amounts of the parent molecule reach the systemic circulation. In vitro systems do not perform conjugation reactions, and would not provide meaningful information regarding TBBPA’s potential for mutagenicity. Conjugation with glucuronide or sulphate is a detoxification mechanism, and mutagenicity of conjugates would not be expected. A two-generation reproduction study in the rat, at doses up to 1000 mg/kg/d, provided no evidence of mutations.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Taking the above data into account, tetrabromobisphenol A does not require classification as mutagenic in accordance with Directive 67/548/EEC and the EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.