Diphosphoric acid, copper salt

Endpoint summary

Description of key information

The terrestrial effects records include 252 good quality single-species chronic NOEC/EC10 values representing different trophic groups (macroorganisms and terrestrial arthropods, microorganisms and plants)which are used for the PNEC derivation in a WoE approach.

Additional information

Data-selection for the environmental hazard assessment

Data are available on a number of substances containing inorganic copper and read-across is justified on the basis that for the purposes of assessing the ecotoxicology of Copper (II) pyrophosphate (copper(2+) diphosphate) the chemical species of interest is copper. As such studies referring to soluble copper ions from any source are considered to be directly relevant to Copper (II) pyrophosphate. Copper (II) pyrophosphate is considered to contribute to copper toxicity in the environment and as such the data assessment and risk assessment focusses on the copper ion as the phosphate ion is not considered to be toxic.

 

In accordance with the EU wide copper risk assessment, the environmental hazard assessment is based on tests carried out with soluble copper species. Studies reporting quantitative dose responses of Cu2+ ions, delivered from soluble copper compounds to aquatic and terrestrial organisms are used for the assessment. Bioavailability of the Cu2+ ions in both laboratory tests and in the environment may be affected by abiotic factors, (such as pH, alkalinity, hardness and DOC for the water compartment) and therefore copper bioavailability is considered for the interpretation of the copper effects data.

 

The terrestrial effects records include 252 good quality single-species chronic NOEC/EC10 values representing different trophic groups (macroorganisms and terrestrial arthropods, microorganisms and plants). These NOECs are carried forward for the terrestrial PNEC derivation in a WoE approach.

Additionally information on 8 single species studies in field contaminated soils and 5 multi-species studies (freshly spiked and field contaminated) were considered in the WoE for the PNEC derivations of the freshwater and the sediment compartment.

 

Considering the importance of bioavailability for reducing the intra-species variability, the database includes supportive information related to the development/validation of the terrestrial copper bioavailability regression models. The bioavailability regression models are used for normalizing the NOECs and deriving the terrestrial PNEC.

Considering the importance of differences in toxicity of copper to terrestrial organisms between lab spiked soils and field contaminated soils, information are available from freshly spiked soils and aged soils.

 

NOECs for soil macroorganisms and terrestrial arthropods:

The invertebrate (including arthropods) effect records include 108 NOEC/(L(E)C10 values; hard and soft bodied organisms with different exposure routes and feeding strategies belonging to 10 different species and 6 different families (i.e. the Eisenia andrei, Eisenia fetida, Lumbricus rubellus belonging to the family of the Lumbricidae; Cognettia sphagnetorum to the family of the Enchytraedae; Isotoma viridis, Folsomia candida, Folsomia fimetaria to the family of the Isotomidae; Hypoaspis aculeifer to the family of the Laelapidae, Platynothrus peltifer to the family of the Camisiidae, Plectus acuminatus to the family of the Plectidae).

Individual high quality NOEC/(L(E)C10 values from different studies range from 8.4 mg/kg for Eisenia andreicoco on production to 1,460 mg/kg for Folsomia candida reproduction.

Remarkably low NOEC values are found in some tests that used Eisenia species (E. fetida and E. andrei). The lowest value is found for E. Andreire production (8.4 mg total Cu/kg) in a natural soil (a German standard soil often used in toxicity tests, LUFA 2.2). This value is below the limit for essentiality. Van Gestel et al, 1989 actually warn against use of cocoon production as reliable endpoint for Eisena Feitida.

 

Important intra-species variability in NOEC/L(E)C10 values are observed due to differences in the physico-chemistry of the soils. For invertebrates, 2 models were developed: the E. fetida model, representing soft-bodied species and the F. candida model representing hard-bodied species. These models were used for the normalization of the invertebrate NOEC data and the derivation of the PNEC.

 

Records are available on the influence of soil ageing/leaching on the plant toxicity, especially those on reported by Ma et al, 2006 and Ma et al, 2006 b – see section adsorption/desorption are also of relevance to the terrestrial PNEC. This information was used for the PNEC derivation relevant to monitoring data.

 

NOECs for plants

The plant effect records include 67 high quality single-species chronic NOEC/EC10 values covering monocotyle and dicotyle plants including agricultural and wild species belonging to 9 different species and 5 different families : (Polygonum convolvulus– family of the Polyonaceae; Lycopersicon esculentum– family of the Solanaceae; Hordeum vulgare, Avena sativa, Pao annua– family of the Poaceae; Senecio vulgaris, Andryala integrifolia, Hypochoeris radicata– family of the Asteraceae; Lolium perenne– family of the Gramineae).The retained NOECs are carried forward to the terrestrial PNEC derivation in a WoE approach.

Individual high quality NOEC/(L(E)C10 values from different studies range between ranging from 18 mg/kg for Hordeum vulgare to 698 mg/kg for Lycopersicon esculentum.

Important intra-species variability in NOEC/L(E)C10 values are observed due to differences in the physico-chemistry of the soils. For plants, 2 models were developed (Rooney et al, 2004 and 2006): L. esculentum model (endpoint yield) and H. vulgare root elongation model. These models were used for the normalization of the plant NOEC data and the derivation of the PNEC.

Additional records are available on the influence of soil chemistry, soil ageing and soil leaching on the plant toxicity (Ginochio et al., 2006; Zhao et al., 2006).

Strandberg et al., 2006 further showed that plant community composition was significantly correlated with soil copper concentration and community composition at soil copper concentrations above 200 mg/kg differed significantly from community composition at lower copper levels. The studies on soil attenuation, reported by Ma et al, 2006 and Ma et al, 2006b (see section adsorption/desorption) are also of relevance to the terrestrial plant PNEC. This information was used for the PNEC derivation relevant to monitoring data.

 

NOECs for soil microorganisms:

The effect records related to microbial processes include 77 NOEC/EC10 values; 9 different endpoints representing the C- and N-cycle and measurement of microbial biomass are available (i.e. maize induced respiration, substrate induced respiration, litter decomposition, glutamic acid decomposition, N-mineralisation, denitrification, nitrification, ammonification, biomass C, biomass N).

Individual high quality NOEC/(L(E)C10 values from different studies range from 30 mg/kg (glucose respiration)) to 2,402 mg/kg (maize respiration).

Important intra-species variability in NOEC:L(E)C10 values are observed due to differences in the physico-chemistry of the soils. For microbial processes, 3 bioavailability models were developed: the nitrification process model, the maize respiration model (using a natural substrate) and the substrate induced respiration model (Smolder and Oorts 2004 and Oorts, 2006a). These models were used for the normalization of the NOEC data for microbial processes and the derivation of the PNEC.

Records are available on the influence of soil ageing/leaching on the plant toxicity (e.g. Chander and Brooks, 1993; Oorts 2006b). This information was used for the PNEC derivation relevant to monitoring data.

 

Toxicity to birds

For toxicity to birds a LD50 of ca. 1400 mg/kg bw was determined in the key study. The toxicity potential of the element copper was judged to be in the same range for bird as it was determined for rats. Therefore no further test was considered necessary as the toxicity in rats was sufficiently evaluated and results were considered transferable to birds.