Manganese dioxide

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

5 January 2009 to15 February 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to valid guidelines and the study was conducted under GLP conditions.

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Water solubility:

>= 0 - <= 0 g/L

Temp.:

20 °C

pH:

>= 5 - <= 6.1

Remarks on result:

other: Solubility was 0.06 to 0.1 mg/L , average 0.073 mg/L

Details on results:

See details below.

Preliminary test results:

Sample number	Concentration (g/L)	Observations
1	1.2E-03	Excess of test material present
2	1.03E-02	Excess of test material present

Definitive test results:

Sample number	Time shaken at approx 30°C (hours)	Time equilibrated at 20°C (hours)	Manganese concentration (g/L)	Equivalent Test Material Concentration (g/L)	Solution pH
1	24	24	4.1E-05	6.5E-05	5.3
2	48	24	6.1E-05	9.7E-05	5.0
3	72	24	3.6E-05	5.7E-05	6.1

 

 

No significant manganese concentration (<0.01 mg/L) was detected in the matrix blank on ICP analysis.

The preliminary water solubility test indicated that the column elution method should have been performed as the solubility was less than 1 x 10^-2 g/L. However, in the absence of a suitable volatile organic solvent for the coating of inorganic substances onto a suitable support material, this method could not be used. Experience has shown that when the support material is coated by substances present as a suspension in a solvent, as opposed to a true solution, the test material breaks away from the support material over time, migrating into the reservoirs and invalidating the determination.

Conclusions:

Interpretation of results: insoluble (< 0.1 mg/L)
The water solubility has been determined to be 4.6E-05 g/L of manganese in solution at 20.0± 0.5°C . This was equivalent to 7.3E-05 g/L (0.073 mg/L) of test material in solution at 20.0 ± 0.5°C based on the manganese content of the test material.

Executive summary:

The water solubility of the test material was determined in a study which was conducted under GLP conditions and in accordance with the standardised guideline EU Method A.6.

Under the conditions of the study the water solubility of the test material was determined to be 0.073 mg/L at 20.0 ± 0.5°C.

It is noted that the saturation concentration of 0.073 mg/L observed in this study is in very good agreement with the Mn concentration found in the 7-d T/Dp study at a loading of 100 mg/L (0.047 mgMn/L).

Description of key information

The water solubility of the test material was determined in a study which was conducted under GLP conditions and in accordance with the standardised guideline EU Method A.6.

Under the conditions of the study the water solubility of the test material was determined to be 0.073 mg/L at 20.0 ± 0.5°C.

It is noted that the saturation concentration of 0.073 mg/L observed in this study is in very good agreement with the Mn concentration found in the 7-d T/Dp study at a loading of 100 mg/L (0.047 mgMn/L).

Key value for chemical safety assessment

Water solubility:

0.073 mg/L

at the temperature of:

20 °C

Additional information

The water solubility of the test material was determined in a study which was conducted under GLP conditions and in accordance with the standardised guideline EU Method A.6.

Under the conditions of the study the water solubility of the test material was determined to be 0.073 mg/L at 20.0 ± 0.5°C.