Reaction mass of copper oxide and manganese dioxide

Endpoint summary

Description of key information

Stability

Hydrolysis: Data waiving acc. to REACH Annex XI, Section 1

Biodegradation

Ready biodegradability: Data waiving acc. to REACH Annex VII, Column 2

Transportation and distribution

Adsorption /desorption:

- Kp (soil): 2363 L/kg / log Kp: 3.4, pH: 7, OC: 2% (Sauvé et al. 2000, RL 2)

- Median Kp (suspended matter) = 30246 L/kg / log Kp (pm/w) = 4.48 (OECD SIDS report, 2014; EU Assessment report, France, 2011)

- Median Kp (sediment) = 24409 L/kg / log Kp (saed/w) = 4.39 (OECD SIDS report, 2014; EU Assessment report, France, 2011)

- For STP partitioning coefficients the median Kp for suspended matter was adopted.

Additional information

Stability

Hydrolysis:

In accordance with REACH Annex XI, Section 1, the study does not need to be conducted, because testing does not appear scientifically necessary, as the submission substance is inorganic. Hydrolysis is defined as a chemical transformation process in which an organic molecule reacts with water. Therefore, a hydrolysis study is scientifically not justified for inorganic substances.

Biodegradation

Ready biodegradability:

In accordance with REACH Annex VII, column 2, the study does not need to be conducted if the submission substance is inorganic.

Transportation and distribution

Adsorption / desorption:

The Kd soil used to describe the adsorption / desorption properties of the reaction mass of copper oxide and manganese dioxide was 2363 L/kg / log Kd: 3.4, assuming a soil solution of pH 7 and OC of 2% (parameters set acc. to REACH Guidance Chapter R.16: Environmental exposure assessment (2016)). The value was derived from Sauvè et al. 2010, which provided an empirical model for calculating Kd soil values for copper that was recommended and used by the EU assessment report on copper oxide (Directive 98/8/EC concerning the placing of biocidal products on the market, Copper (II) oxide, 2011, France). Kd soil values for the element copper were preferred to Kd values for manganese, because the hazard assessment was based on soluble copper as it was the more hazardous element of the submission substance compared to manganese. In addition, copper has also the slightly higher Kd soil compared to manganese.

Typical Kd / Kp values for copper to freshwater, suspended matter and freshwater sediment were provided in the OECD SIDS report (2014) and the EU Assessment report for copper(II)oxide (France, 2011). The following Kp values were used for the environmental risk assessment of the submission substance: Kp (suspended matter) = 30246 L/kg / log Kp (pm/w) = 4.48 (50th percentile); Kp (sediment) = 24409 L/kg / log Kp (sed/w) = 4.39 (50th percentile). For STP partitioning coefficients the median Kp for suspended matter was adopted.

In case of decreasing pH, the adsorption potential of the submission substance may decrease; vice versa, with increasing pH the adsorption potential of the reaction mass may increase. Therefore, environmental compartment-specific or site-specific environmental risk assessment may be necessary.