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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The studies on adsorption/desorption (for the Read-across substance charcoal) are summarised in the following table:

Table17: Overview of studies on adsorption/desorption

Method

Results

Remarks

Reference

Study type: Adsorption / desorption screening

Method: HPLC estimation method

Guideline: OECD 121;

EU Method C.19

log Koc: < 1.5 at 25 °C

Klimisch Score 1 (reliable without restriction)

Key study

Experimental result

Henke et al. (2010)

Discussion

The study was performed using HPLC with a cyanopropyl chemical bound resin on a silica based column as stationary phase (pH = 5.5; 25 °C). As mobile phase methanol/water (55/45% v/v) was used. Seven reference items with different retention times (tR) were chosen for the calibration on behalf of the retention time of the test item charcoal (Probe 2: C-Fix =80.5%) on the column.

First, a solution of the reference items was measured three times with HPLC, then a solution of the test item (three measurements), and finally the solution of the reference items was again measured three times.

For each reference item, the capacity factor k’ was calculated from the retention time of an unretained compound (sodium nitrate) and the retention time of the respective reference item. A calibration function was set up using the literature values for KOCof the reference items and the mean capacity factor of the six determinations. Based on the data set log k’ versus log KOC, the equation for the regression line was calculated.

The chromatogram of the test item showed one peak (mean TR= 2.254 min). The log KOCwas calculated as 0.661±0.026, with a range of 0.633–0.686. As this log KOCvalue lies outside the calibration range obtained with the used reference substances (1.32-5.63) and also outside the determinable log KOCrange of the HPLC screening method (according to OECD guideline 121: 1.5-5.0), the log KOCof the test item charcoal (Probe 2: C-Fix = 80.5%) should be stated as <1.5.

Due to the limited solubility of the test item charcoal (Probe 2: C-Fix = 80.5%) in the solvent, an extract instead of a solution was used for the measurements. Therefore, the results are necessarily related to the used charcoal extract with a nominal concentration of 208,910 mg/L in methanol/water (75/25%, v/v) under the testing conditions used (25±1°C; pH 5.5).

Further information on adsorption/desorption according to REACh Regulation (EC) No. 1907/2006, Annex IX, 9.3.3. column 1, is not required as charcoal is highly insoluble in water and the overall potential of charcoal to become adsorbed to soil / sediment is extremely low.

The following information is taken into account for any environmental exposure assessment:

The adsorption coefficient KOCof charcoal (Probe 2: C-Fix = 80.5%) was determined using the HPLC method in accordance with the OECD guideline no. 121 and in compliance with GLP standards.