Iodine pentafluoride

Endpoint summary

Additional information

Due to the fact that the substance violently reacts with moisture and produces hydrofluoric and iodic acids, classification for toxicity is based on fluoride and iodate:

The genotoxic potential of fluoride was investigated in three in vitro studies and in one in vivo study. Hydrogen fluoride was tested in an Ames test both with and without S9 activation (Herbold 1987). The salmonella mutants tested were the strains TA 1535, TA 100, TA 1537 and TA 98. The substance was tested up to a concentration of 1800 µg per plate (at higher concentrations cytotoxicity was observed). There was no evidence of mutagenic activity at any concentration tested with and without metabolic activation. The results of the chromosome aberration test were inconclusive (NTP 1990). The two laboratories used to test the effects of sodium fluoride on CHO cells showed conflicting results; one reported a negative result and one reported a positive result for both induction of sister chromatid exchanges and chromosomal aberrations. The mutagenic activity of sodium fluoride was also tested in a mammalian cell mutagenicity study under neutral and acidic conditions in the V79/HGPRT system (Slamenova 1996). Sodium fluoride treatment did not result in any mutagenic activity. An in vivo micronucleus test and chromosome aberration test also indicated no mutagenicity of fluoride (Zeiger 1994). Mice were exposed to sodium fluoride via the drinking water for 1 or 6 weeks. No evidence of micronuclei formation was seen in peripheral blood erythrocytes after 1 or 6 weeks and no evidence of chromosomal aberration was seen in bone marrow cells after exposure for 6 weeks.

The genotoxic potential of potassium iodate was investigated in vitro, using the alkaline comet assay and the cytokinesis-block micronucleus assay (Poul 2004). The comet assay did not detect the presence of DNA damage after a treatment with potassium iodate at concentrations up to 10 mM. This absence of primary DNA damage (DNA strand breaks and abasic sites) after potassium iodate exposure was confirmed by the absence of clastogenic effects in the cytokinesis-block micronucleus assay. In conclusion, the results clearly indicated that potassium iodate had no mutagenic effects in CHO cells at concentrations up to 10 mM.

Furthermore, the results of a 2-year oral (drinking water) study with potassium iodide (KI) in rats do not raise concern with regard to carcinogenicity of iodine (Takegawa, 2000). In this study squamous cell carcinomas (SCC) occurred in the submandibular salivary gland of a few rats of both sexes at the highest dose level tested (1000 ppm KI in the drinking water, corresponding to 53 and 67 mg/kg bw/day in male and female rats, respectively) but no treatment-related tumors were observed in the thyroid or other organs and tissues. The accompanying histopathological changes in the salivary gland (focal acinar atrophy, ductular proliferation, squamous metaplasia in the epithelium of proliferating ductules) suggested that the SCC resulted from an epigenetic mechanism, only active at high doses. The dose at which SCC were seen in the rat study is about 4000-5000 times higher than the tolerable daily intake (TDI) for iodine of 0.01 mg/kg bw/day established by the World Health Organisation (WHO, 2009). Taken together, these data indicate that the iodine moiety of iodine pentafluoride does not present a risk with regard to carcinogenicity.

 

Short description of key information:
No studies with iodine pentafluoride are available. However, reliable studies with the read-across substances sodium fluoride, hydrogen fluoride and potassium iodate do not indicate mutagenicity of fluoride or iodate.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Due to the fact that the substance violently reacts with moisture and produces hydrofluoric and iodic acids, classification for toxicity is based on fluoride and iodate according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 and according to EU Directive 67/548/EEC. Since IO3- and F- are not mutagenic, no classification is needed.