Cuprate(4-), [.mu.-[[3,3'-[(1-oxido-1,2-diazenediyl)bis[[2-(hydroxy-.kappa.O)-4,1-phenylene]-2,1-diazenediyl-.kappa.N1]]bis[4-(hydroxy-.kappa.O)-2,7-naphthalenedisulfonato]](8-)]]di-, ammonium sodium

Endpoint summary

Additional information

Biodegradation

Biodegradation in water: screening tests

Key study

The carbon dioxide evolution test (former Sturm test) is a static method to evaluate the ultimate aerobic biodegradability of a test substance in water. The test was conducted according to guideline under GLP conditions. The test substance, a defined inorganic medium and inoculum (municipal activated sludge from wastewater treatment plant) were incubated and aerated at up to 28 days. The biologically produced carbon dioxide is trapped and measured. The biodegradation degree is expressed as produced carbon dioxide in relation to the calculated theoretical carbon dioxide value (ThCO2) using the initial concentration of total organic carbon of the test substance (TOC). In addition, the dissolved organic carbon (DOC) content was determined to be < 10%.

The degree of biodegradation was < 10% CO2/ThCO2 after an exposure period of 28 days. The test substance was not readily biodegradable under the conditions of this test. The required pass level for ready biodegradability within a ten days window was not reached.

 

Supporting study

The bioelimination of the test substance (12% act. ingr.) was determined in a Zahn-Wellens/EMPA test according to OECD 302B. The test substance was tested at a nominal concentration of 1 mg/L. Two tests were running parallel. The test was terminated after 3 hours, because only the bioelimination by adsorption should be determined. The adsorption of the test substance after 3 hours was 80%.

Adsorption/desorption

Following Koc QSAR data have been derived from EPI Suite: First Order Molecular Connectivity Index log Koc was calculated to be 10.5140 and KOC to be 1E+010 L/kg repectively. Using the KOW method the log KOC was calculated to be 5.4189 and the KOC to be 2.624E+005 L/kg respectively. The values were calculated for the freee acid of the test substance. The data showed that the free acid of the substance is not within the applicability domain.

QSAR-disclaimer

In Article 13 of Regulation (EC) No 1907/2006, it is laid down that information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI (of the same Regulation) are met. Furthermore according to Article 25 of the same Regulation testing on vertebrate animals shall be undertaken only as a last resort.

According to Annex XI of Regulation (EC) No 1907/2006 (Q)SAR results can be used if (1) the scientific validity of the (Q)SAR model has been established, (2) the substance falls within the applicability domain of the (Q)SAR model, (3) the results are adequate for the purpose of classification and labeling and/or risk assessment and (4) adequate and reliable documentation of the applied method is provided.

For the assessment of [mu-[[3,3'-[(1-oxido-1,2-diazenediyl)bis[[2-(hydroxy-kappa-O)-4,1-phenylene]-2,1-diazenediyl-kappa-N1]]bis[4-(hydroxy-kappa-O)-2,7-naphthalenedisulfonato]](8-)]]dicopper, tetrasodium salt (Q)SAR results were used for Adsorption / desorption.The criteria listed in Annex XI of Regulation (EC) No 1907/2006 are considered to be adequately fulfilled and therefore the endpoint(s) sufficiently covered and suitable for risk assessment. Therefore, further experimental studies on adsorption / desorption are not provided.