Diphosphoric acid, copper salt

Sediment toxicity

Link to relevant study record(s)

Reference

Endpoint:

sediment toxicity, other

Remarks:

short and long term

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
For further information please refer to read across justification in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Remarks on result:

other: The Individual NOEC values range between 18.3 mg/kg dry weight and >3,158 mg/kg (min-max value).

Validity criteria fulfilled:

not applicable

Conclusions:

The freshwater sediment effect records include 62 high quality single-species chronic NOEC/L(E) C10 values from 6 different sediment- dwelling species of relevance to set the freshwater aerobic sediment PNEC in a WOE approach.

Description of key information

The freshwater sediment effect records include 62 high quality single-species chronic NOEC/L(E) C10 values from 6 different sediment- dwelling species of relevance to setting the freshwater aerobic sediment PNEC in a WOE approach. Considering the importance of bioavailability for reducing the intra-species variability, the database includes supportive information related to the development/validation of the sediment organic carbon normalization. The NOECs and OC normalization model are used for the aerobic sediment PNEC derivation. Information in support of the protective effect of sediment sulphides is useful to the risk characterization.

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 high quality records retained for the PNEC derivation of copper under the Existing Substances Regulation (TC NES) and Biocidal Products regulations (Technical meetings) have been included in the IUCLID data-base. Tests that were considered as not-reliable for the PNEC derivations have NOT been included in the IUCLID records but have been summarized in the copper RA report (2008).

 

Effects on freshwater sediment

106 high quality chronic NOEC/(L(E) C10 values are available for 6 different sediment- dwelling organisms. the amphipodsHyalella Azteca and Gammarus pulex, the oligochaetes Tubifex tubifex and Lumbriculus variegatus, the insect Chironomus ripariusand the insect Hexagenia.

The Individual NOEC values range between 18.3 mg/kg dry weight and >3,158 mg/kg (min-max value). Large intra-species variability are observed due to variations in organic carbon (OC) content and acid volatile sulphide (AVS) content of the sediments (De Schamphelaere et al.,2005). Normalization of the NOECs/(L(E) C10 for OC was demonstrated. Normalization of the effects data for AVS was not possible and therefore only NOEC/(L(E) C10 values generated under conditions that represent “aerobic” conditions (Low AVS) were considered as adequate for the PNEC derivation. Effects data from studies with AVS concentration lower than the 10th percentile of the AVS concentration (i. e. 0.77 mmol/kg dry weight) were thus retained. Using this exclusion rule, the original dataset containing 106 NOEC values was reduced to a trimmed data set of 62 NOEC values for copper.

 

The data base includes additional information in support of the importance if AVS binding in the field (Boothman et al., 2001) and demonstrating the lesser sensitivity of algae in the biofilm compared to free living algae(Barranguet et al., 2000)and the applicability of long term benthic studies to the life cycle (Pasteris et al., 2003).

 

The records related to effects observed in freshwater mesocosm studies (multi-species, covering water and sediment) are included in section 6.6. (additional ecotoxicological information). Copper threshold values from three high quality mesocosm studies, representing lotic and lentic systems are available.