Pentasodium triphosphate

Endpoint summary

Additional information

Pentasodium triphosphate (90% purity) was assessed in a modified Ames test at concentrations between 5 and up to 5000 μg/plate, with and without metabolic activation (Shimizu et al., 1985). The preincubation method was used in the presence of metabolic activation. The bacterial strains used were Salmonella typhimurium strains TA98, TA100, TA1535, TA1537 and TA1538, and Escherichia coli WP2uvrA. The test was performed in duplicate, and appropriate positive and negative controls were used. No cytotoxic effects were observed. No increase in the number of revertants was observed, with or without S-9 mix. No mutagenic activity was found in a reverse mutation assay performed in Salmonella typhimurium strains TA92, TA94, TA98, TA100, TA1535, and TA1537 with STPP (84.1% purity) at concentrations up to 10 mg/plate (Ishidate et al. 1984). Limited documentation was available on methodology and test results (no positive controls, no details on doses tested, no indication of cytotoxicity). However, test results support the absence of mutagenic activity of sodium tripolyphosphate STPP (84.1% purity) was assessed for chromosomal aberrations in Chinese Hamster fibroblasts cell line (CHL) (Ishidate et al. 1984). Cells were treated at 3 different doses for 24 or 48 hours, without metabolic activation. The maximum dose tested was determined in a preliminary assay not reported in the publication. The value of the maximum concentration tested (determined in a preliminary assay) was 84.1 mg/plate. One hundred well-spread metaphases were analysed for incidence of polyploid cells, structural aberrations (chromatid or chromosome gaps, breaks, exchanges, ring formations, fragmentations and others). No significant effects were observed. Reporting of the methodology and results was rather limited. No metabolic activation was used. There was no information on cytotoxicity, and whether the test concentrations were optimal. No positive controls were included. These negative results were further supported by another publication reporting the results of a chromosomal aberration assay in Chinese Hamster fibroblasts cell line (CHL) (Ishidate et al. 1988). STPP was tested at a maximum concentration of 500 μg/ml (1.4 mM) for a treatment time of 48 hours. No other doses were mentioned. The vehicle was not indicated. No metabolic activation was used. No structural aberrations were reported. Limited documentation was available on test conditions and results.

Although limited documentation was generally available on these assays reported in the literature, altogether the negative results obtained in various assays support the lack of evidence for genetic toxicity for STPP in vitro and in vivo

Short description of key information:
The available in vitro genotoxicity studies were not performed according to current guidelines and GLP. However, STPP was found not mutagenic in several reliable in vitro and in vivo studies, including Ames tests in S. typhimurium and E. coli, chromosomal aberration test in CHL cells (Shimizu et al., 1985; Ishidate et al., 1984, 1988) and dominant lethal assay and gene mutation assay (Weir, 1975).

Endpoint Conclusion: No adverse effect observed (negative)