Cadmium sulfoselenide

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Series on Testing and Assessment No. 29 (23-Jul-2001): Guidance document on transformation/dissolution of metals and metal compounds in aqueous media

GLP compliance:

yes

Other quality assurance:

ISO/IEC 17025 (General requirements for the competence of testing and calibration laboratories)

Type of method:

flask method

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.1 µg/L

Element analysed:

cadmium

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH 6

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.1 µg/L

Element analysed:

cadmium

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH 6

Details on results:

The temperature of the test solutions fluctuated between 21.2 and 22.7°C during the tests, the pH remained constant at ± 0.2 units, and the dissolved oxygen concentration was always maintained above 70% (± 5.95 mg/L) of its saturation in air (± 8.50 mg/L). The non-purgeable dissolved organic carbon content (NPDOC) of the (modified) ISO 6341 aqueous media was below the reporting limit (<0.5 mg/L).
The acute (7d) Transformation/Dissolution Test on CdSSe in a standard aqueous medium at pH 6 and with a 1 mg/L loading showed an average dissolved cadmium concentration of <0.1 μg/L Cd . CdSSe contains 66.3% (w/w) cadmium. This means that <0.015% of the total introduced cadmium went into the test system as dissolved cadmium after 7 days.
The Chronic (28d) Transformation/Dissolution Test on CdSSe in a standard aqueous medium at pH 6 and with a 1 mg/L loading showed an average dissolved cadmium concentration of 0.14 ± 0.03 μg/L Cd. This means that about 0.02% of the total introduced cadmium went into the test system as dissolved cadmium after 28 days.

Conclusions:

Interpretation of results: insoluble (< 0.1 mg/L)
Tests were done according to standard OECD protocol and considered of good quality.

Executive summary:

In this study, a loading of 1 mg/L of CdSSe was agitated at 100 rpm in a pH buffered aqueous medium at pH 6 for 28 days. The solutions were sampled at specific time intervals and the concentrations of dissolved cadmium in water were determined.

The acute (7d) Transformation/Dissolution Test on CdSSe in a standard aqueous medium at pH 6 and with a 1 mg/L loading showed an average dissolved cadmium concentration of <0.1μg/L Cd

The Chronic (28d) Transformation/Dissolution Test on CdSSe in a standard aqueous medium at pH 6 and with a 1 mg/L loading showed an average dissolved cadmium concentration of 0.14 +/- 0.03 μg/L Cd.

Reference 2

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Series on Testing and Assessment No. 29 (23-Jul-2001): Guidance document on transformation/dissolution of metals and metal compounds in aqueous media

GLP compliance:

yes

Other quality assurance:

ISO/IEC 17025 (General requirements for the competence of testing and calibration laboratories)

Type of method:

flask method

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.2 µg/L

Element analysed:

cadmium

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH 6

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.2 µg/L

Element analysed:

cadmium

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH 6

Details on results:

The temperature of the test solutions fluctuated between 21.2 and 22.7°C during the tests, the pH remained constant at ± 0.2 units, and the dissolved oxygen concentration was always maintained above 70% (± 5.95 mg/L) of its saturation in air (± 8.50 mg/L). The non-purgeable dissolved organic carbon content (NPDOC) of the (modified) ISO 6341 aqueous media was below the reporting limit (<0.5 mg/L).
The acute (7d) Transformation/Dissolution Test on CdSSe in a standard aqueous medium at pH 6 and with a 1 mg/L loading showed an average dissolved cadmium concentration of 0.24 +/-0.09 μg/L Cd. CdSSe contains 66.3% (w/w) cadmium. This means that 0.036% of the total introduced cadmium went into the test system as dissolved cadmium after 7 days.
The Chronic (28d) Transformation/Dissolution Test on CdSSe in a standard aqueous medium at pH 6 and with a 1 mg/L loading showed an average dissolved cadmium concentration of 0.23 ± 0.13 μg/L Cd. This means that about 0.035% of the total introduced cadmium went into the test system as dissolved cadmium after 28 days.

Conclusions:

Interpretation of results (migrated information): insoluble (< 0.1 mg/L)
Tests were done according to standard OECD protocol and considered of good quality.

Executive summary:

In this study, a loading of 1 mg/L of CdSSe was agitated at 100 rpm in a pH buffered aqueous medium at pH 6 for 28 days. The solutions were sampled at specific time intervals and the concentrations of dissolved cadmium in water were determined.

The acute (7d) Transformation/Dissolution Test on CdSSe in a standard aqueous medium at pH 6 and with a 1 mg/L loading showed an average dissolved cadmium concentration of 0.24 +/- 0.09 μg/L Cd.

The Chronic (28d) Transformation/Dissolution Test on CdSSe in a standard aqueous medium at pH 6 and with a 1 mg/L loading showed an average dissolved cadmium concentration of 0.23 +/- 0.13 μg/L Cd.

Description of key information

Transformation/dissolution tests were performed on the substance to check the solubility under environmentally relevant conditions. The results demonstrate the highly insoluble character of the substance: only 0.026% and 0.028 % of the Cd contained in the substance was solubilised after 7days and 28 days of testing, respectively.
The experimentally determined average water solubility of Cd in the substance is 12 mg/l at a pH range of 5.6 -6.04 (Outotec, 2010). However, as >75% of the particles have a size < 20 µm, one cannot avoid the occurence of particles in the solution tested and the value was not taken forward in this assessment.

Key value for chemical safety assessment

Water solubility:

0.19 µg/L

at the temperature of:

22 °C

Additional information

Average solubility of Cd, measured on 2 substance samples tested at 1mg/l loading according to OECD protocol "OECD Series on Testing and Assessment No. 29", was 0.17 and 0.185 µg Cd/l after 7days and 28 days of testing, respectively. This value is relevant for the solubility of the substance in the aquatic environment, and demonstrates the highly insoluble character of the substance, resulting in its lack of aquatic hazard.