Copper iodide

Adsorption / desorption

Description of key information

Copper:

-Aquatic compartment

Partition coefficient in freshwater suspended matter          Kpsusp= 30,246 l/kg (log Kp (pm/w) = 4.48) (50thpercentile)

Partition coefficient in freshwater sediment                        Kpsed = 24,409 l/kg (log Kp(sed/w) = 4.39) (50th percentile)

Partition coefficient in estuarine suspended matter             Kpsusp= 56,234 l/kg (log Kp (pm/w) = 4.75) (50thpercentile)

Partition coefficient in marine suspended matter                Kpsusp= 131,826 l/kg (log Kp (pm/w) = 5.12) (50thpercentile)

-Terrestrial compartment

Partitioning coefficient                                                    Kd value soil: 2120 L/kg(log Kp (pm/w) = 3.33) (50thpercentile)

Iodine:

For determination of the Koc value the report of Ashworth is used. Based on the final result for oxic conditions a value of 7.7 L/kg is observed after 49 days. The organic partition is about 4.7 %. Thus, according to the TGD R.16 eq. R16-6 the Koc value is 1.64 L/kg. For anoxic conditions the Koc is 0.47 L/kg.

Key value for chemical safety assessment

Other adsorption coefficients

Type:

other: log Kp (solids-water in soil) for iodine

Value in L/kg:

0.89

at the temperature of:

20 °C

Additional information

COPPER

Relevant partitioning coefficients are available from literature.

- For the aquatic compartment, the summaries from Heijerick and Van Sprang (2005 and 2008) have been agreed under the copper RAR (2008) and are used the risk characterization.

- For the terrestrial compartments, in the RA report, preference has been given to the Sauvé et al dataset as it covers the widest range of soil conditions relevant for the risk assessment and these have been used for the risk characterization under the copper RAR (2008).

-Aquatic compartment

Partition coefficient in freshwater suspended matter       Kpsusp= 30,246 l/kg (log Kp (pm/w) = 4.48) (50thpercentile)

Partition coefficient in freshwater sediment                   Kpsed = 24,409 l/kg (log Kp(sed/w) = 4.39) (50th percentile)

Partition coefficient in estuarine suspended matter        Kpsusp= 56,234 l/kg (log Kp (pm/w) = 4.75) (50thpercentile)

Partition coefficient in marine suspended matter            Kpsusp= 131,826 l/kg (log Kp (pm/w) = 5.12) (50thpercentile)

-Terrestrial compartment

Partitioning coefficient                                                 Kd value soil: 2120 L/kg(log Kp (pm/w) = 3.33) (50thpercentile)

Information on short term and long term attenuation of copper in soils as a function of soil chemistry was assessed by Ma et al., 2006a & 2006b. The soil and environmental factors governing short term attenuation and ageing rates are soil pH, organic matter content, incubation time and temperature with soil pH being the key factor for ageing of Cu added to soils. 

From the field experiments and a mechanistic understanding of the decrease in bioavailable copper as a function of time following exposures, an ageing factor of 2 was derived as a reasonable worst case when considering field exposure data. This information is relevant to the soil PNEC derivation.

IODINE:

Although the data were not obtained according a standard test guideline and GLP, the new mini-column approach of Ashworth et al. (Ashworth, 2006) can be supposed to be adequate and reliable for the environmental risk assessment of iodine.

In the study the long-term behavior of iodine under more realistic soil moisture conditions as well as the changes in behavior with time-dependent variations of the soil redox conditions is observed. In contrast to a short-term batch equilibrium HPLC method this long-term experiment gives the opportunity of a more exact examination of the partitioning of a chemical in soil. In addition, Ashworth et al. (Ashworth, 2006) were able to observe the behavior of iodine in oxic and anoxic soil redox conditions.

The obtained results for iodine seem to be consistent with geometric mean compendia values and indicate that iodine within oxic environments is less mobile and, probably, less bio-available than in anoxic environments.