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As in surface waters, LiPF6 itself will not be present in the soil compartment: rather the F-, Li+ and phosphate ions will be present in the unexpected event of significant LiPF6 release. From the reported data on toxicity to mammalian and aquatic organisms, it is clear that fluoride is the most toxic of the degradation products and it is therefore appropriate to focus on this to evaluate toxicity to terrestrial organisms. The HF: EU Risk Assessment Report (2001) reviewed results of toxicity tests using a soil arthropod, earthworms and soil microbes: among these, soil microbes were found to be most sensitive to fluoride. Van Wensem and Adema (1991) used potassium fluoride to determine the inhibitory effect of fluoride on microbial mineralisation (ammonia, nitrate and phosphorus) in a leaf-litter micro-ecosystem tested with and without inclusion of soil arthropods. After 9 weeks, arthropod survival was unaffected at the highest fluoride concentration tested (170 µmol/g) . Mineralisation of nitrate proved to be the most sensitive to fluoride, the NOEC for nitrification being 5.3 µmol F-/g dry weight of litter (reported as 106 mg/kg in the HF: EU Risk Assessment Report, 2001).

Atmospheric exposure to fluoride in gaseous and/or particulate form can cause photoxicity in sensitive plant species. In conifers, prolonged exposure to a fluoride concentration of 0.9 microgrammes fluoride/cu.m appears sufficient to cause visible damage. Given the natural background level of fluoride present in soil (e.g. 200-700 mg/kg, reported for various soil types: HF - EU RAR, 2001), no trace quantity addition from LiPF6 use is likely to adversely affect higher plant growth.