Cobalt hydroxide oxide

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

GLP compliance:

no

Remarks:

The tests were following as close as possible the GLP guidelines proposed by OECD

Type of method:

flask method

Water solubility:

0.4 µg/L

Temp.:

20.7 °C

pH:

5.91

Remarks on result:

other: Co(OH)O concentration at 0 hour sampling time at 1 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Water solubility:

4.8 µg/L

Temp.:

21.2 °C

pH:

6.05

Remarks on result:

other: Co(OH)O concentration at 24 hour sampling time at 1 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Water solubility:

6.4 µg/L

Temp.:

21.3 °C

pH:

6.04

Remarks on result:

other: Co(OH)O concentration at 48 hour sampling time at 1 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Water solubility:

8.2 µg/L

Temp.:

21.4 °C

pH:

6.03

Remarks on result:

other: Co(OH)O concentration at 96 hour sampling time at 1 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Water solubility:

11.6 µg/L

Temp.:

21.2 °C

pH:

5.96

Remarks on result:

other: Co(OH)O concentration at 168 hour sampling time at 1 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Water solubility:

30.7 µg/L

Temp.:

22.6 °C

pH:

6.06

Remarks on result:

other: Co(OH)O concentration at 672 hour sampling time at 1 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Water solubility:

2.1 µg/L

Temp.:

21.7 °C

pH:

5.9

Remarks on result:

other: Co(OH)O concentration at 0 hour sampling time at 10 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Water solubility:

48.7 µg/L

Temp.:

23 °C

pH:

6.02

Remarks on result:

other: Co(OH)O concentration at 24 hour sampling time at 10 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Water solubility:

68.7 µg/L

Temp.:

22.1 °C

pH:

6.03

Remarks on result:

other: Co(OH)O concentration at 48 hour sampling time at 10 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Water solubility:

88.2 µg/L

Temp.:

21.9 °C

pH:

6.21

Remarks on result:

other: Co(OH)O concentration at 96 hour sampling time at 10 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Conclusions:

Under the conditions of the transformation/dissolution test, the dissolution of Co(OH)O is 30.7 µg/L at 1 mg/L loading for the 28-day endpoint.
The dissolution of Co(OH)O is 105.4 µg/L at 10 mg/L loading for the 7-day endpoint.
The dissolution of Co(OH)O is 858.5 µg/L at 100 mg/L loading for the 7-day endpoint.

Executive summary:

A seven day transformation/dissolution test according to the OECD guideline 29 and the GHS (Annex 10) protocol was run on Co(OH)O at a mass loading of 10 and 100 mg/L, at a pH of 6.0 Also a 28 day transformation/dissolution was run on Co(OH)O at a mass loading of 1 mg/L and at a pH of 6.0. Under the conditions of this test, the dissolution of Co(OH)O is 30.7 µg/L for the 28 -day endpoint (1 mg/L loading), 105.4 µg/L for the 7 -day endpoint (10 mg/L loading) and 858.5 µg/L for the 7 -day endpoint (100 mg/L loading).

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

GLP compliance:

no

Remarks:

The tests were following as close as possible the GLP guidelines proposed by OECD

Type of method:

flask method

Water solubility:

105.4 µg/L

Temp.:

22.1 °C

pH:

6.06

Remarks on result:

other: Co(OH)O concentration at 168 hour sampling time at 10 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Water solubility:

11.6 µg/L

Temp.:

21.5 °C

pH:

5.85

Remarks on result:

other: Co(OH)O concentration at 0 hour sampling time at 100 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Water solubility:

392.2 µg/L

Temp.:

21.4 °C

pH:

6.21

Remarks on result:

other: Co(OH)O concentration at 24 hour sampling time at 100 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Water solubility:

514.7 µg/L

Temp.:

20.4 °C

pH:

5.98

Remarks on result:

other: Co(OH)O concentration at 48 hour sampling time at 100 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Water solubility:

651.6 µg/L

Temp.:

21.9 °C

pH:

6.21

Remarks on result:

other: Co(OH)O concentration at 96 hour sampling time at 100 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Water solubility:

858.5 µg/L

Temp.:

20.7 °C

pH:

6.04

Remarks on result:

other: Co(OH)O concentration at 168 hour sampling time at 100 mg/L loading. Sample analysis was conducted in triplicate per test vessel (3 test vessels per loading). Average value from the tests is given.

Conclusions:

Under the conditions of the transformation/dissolution test, the dissolution of Co(OH)O is 30.7 µg/L at 1 mg/L loading for the 28-day endpoint.
The dissolution of Co(OH)O is 105.4 µg/L at 10 mg/L loading for the 7-day endpoint.
The dissolution of Co(OH)O is 858.5 µg/L at 100 mg/L loading for the 7-day endpoint.

Executive summary:

A seven day transformation/dissolution test according to the OECD guideline 29 and the GHS (Annex 10) protocol was run on Co(OH)O at a mass loading of 10 and 100 mg/L, at a pH of 6.0 Also a 28 day transformation/dissolution was run on Co(OH)O at a mass loading of 1 mg/L and at a pH of 6.0. Under the conditions of this test, the dissolution of Co(OH)O is 30.7 µg/L for the 28 -day endpoint (1 mg/L loading), 105.4 µg/L for the 7 -day endpoint (10 mg/L loading) and 858.5 µg/L for the 7 -day endpoint (100 mg/L loading).

Reference 3

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006-09-19 to 2006-12-04

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The stability of the test substance is missing.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

, 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

, 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2005-11

Type of method:

column elution method

Water solubility:

1 084 µg/L

Conc. based on:

element

Incubation duration:

ca. 95 h

Temp.:

20 °C

pH:

>= 7.22 - <= 7.71

Remarks on result:

other: loading: 128.8 mg of the test item was mixed with 6.35 g of glass beads

Water solubility:

55 µg/L

Conc. based on:

element

Incubation duration:

ca. 95 h

Temp.:

37 °C

pH:

>= 7.92 - <= 8.21

Remarks on result:

other: loading: 122.10 mg of test item was mixed with 6.22 g of glass beads

Details on results:

Total elution times were about 95 hours at 20°C and at 37°C. The measured results differ by less than 30%. Therefore, the study is considered to be valid.

The water solubility of Cobald oxyhydroxide was found to be

at 20 °C: 1084 µg/L (+/- 63 µg/L)

at 37 °C: 55 µg/L (+/-3.4 µg/L)

using the column elution method.

Conclusions:

Interpretation of results: slightly soluble (0.1-100 mg/L)
The water solubility of Cobalt oxyhydroxide was found to be at 20 °C 746 µg/L (+/-43 µg/L) and at 37 °C 38.1 µg/L (+/-2.3 µg/L) using the column elution method.

Description of key information

Cobalt hydroxide oxide has a water solubility of 746 µg/L (+/-43 µg/L) at 20 °C and 38.1 µg/L (+/-2.3 µg/L) at 37 °C.

Key value for chemical safety assessment

Water solubility:

746 µg/L

at the temperature of:

20 °C