Registration Dossier

Administrative data

Key value for chemical safety assessment

Additional information

With single superphosphate only a chromosome aberration study is present. A reliable Ames test and TK-assay is not available with the substance itself.

In an Ames test with triple superphosphate according to OECD 471 guideline, Salmonella Typhimurium strains TA 98, TA 100, TA 1535 and TA 1537 and E. Coli WP2 uvr A showed no genotoxicity with and without metabolic activation, showing cytotoxicity at the highest concentrations tested. In an vitro chromosome aberration test with CHO cells performed according to OECD 473 guideline, also no genotoxicity was seen with and without metabolic activation when exposed to single superphosphate. Precipitation was observed. With ammonium dihydrogenorthophosphate a reliable TK-assay was present. In a Thymidine kinase (TK) assay in L5178Y mouse lymphoma cells performed according to OECD 476 and EC B.17 guidelines, the substance did not induce a significant increase in the mutation frequency. Based on these negative results for genotoxicity in in vitro studies, no in vivo studies are necessary.

Short description of key information:
No reliable Ames and TK assay with single superphosphate is present. However, a reliable chromosome aberration study with human lymphocytes exposed to single superphosphate showed no genotoxicity. Based on reliable in vitro study with triple superphosphate, the Ames test were negative in the presence and absence of metabolic activation. A reliable in vitro TK assay with ammonium dihydrogenorthophosphate is present showing negative results in the presence and absence of metabolic activation.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based on the available data, single superphosphate does not have to be classified according to Directive 67/548/EC and the CLP Regulation for genetic toxicity.