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Ecotoxicological information

Toxicity to soil microorganisms

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Description of key information

Most sensitive values (with background correction) on microbial toxicity testing for different functional parameters and microbial species are summarised in the EU-RAR (2008). According to these data, the effect concentrations for Trinickel Dicitrate were calculated:
carbon cycle (glucose respiration): EC10 (24h) = 120 mg Trinickel Dicitrate/kg dw
carbon cycle (soil respiration): NOEC (28 d) = 129 mg Trinickel Dicitrate/kg dw
nitrogen cycle (nitrification): EC10 (4-28d) = 198 mg Trinickel Dicitrate/kg dw
nitrogen cycle (mineralisation): EC10 (28d) = 88 mg Trinickel Dicitrate/kg dw
enzymatic (dehydrogenase): EC10 (no data) = 86 mg Trinickel Dicitrate/kg dw
Aspergillus clavatus (hyphal growth): EC10 (no data) = 101 mg Trinickel Dicitrate/kg dw

Key value for chemical safety assessment

Additional information

Data on microbial toxicity tests resulting in NOEC values are summarised in Table 3.2.3-5 of the EU-RAR (2008). This table was attached to the key study record of chapter 6.3.4. Tests on microbial processes are multi-species test, in which the native soil microbial community is exposed. The selected NOEC or EC10 values comprise functional parameters (n=39), and microbial species (n=13). The functional parameters are based on the carbon cycle (n=27), nitrogen cycle (n=12), including denitrification and mineralization of specific substrates. Enzymatic parameters are also further considered in the effects assessment. 6 different enzymatic processes were compiled in the database.

In the total risk approach, NOEC or EC10 values with background correction range from 28 mg Ni/kg (nitrification mineralisation) to 2491 mg Ni/kg (respiration) and 88 mg Trinickel Dicitrate/kg dw and 7839 mg Trinickel Dicitrate/kg dw, respectively. Most of the data are part of a research projekt on the ‘development of a predictive model of bioavailbility and toxicity of nickel in soils’, and therefore not public available. Thus only detailed data on soil respiration were shown here.