Registration Dossier

Environmental fate & pathways

Additional information on environmental fate and behaviour

Administrative data

Endpoint:
additional information on environmental fate and behaviour
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Performed in accordance to the general guidance given in the draft OECD Transformation/Dissolution protocol. The experimental design includes the refinements, agreed by the ad hoc OECD Validation Management Group (VMG), as described in the Standard Operating Procedures prepared by CANMET and LISEC

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: General guidance given in the draft OECD Transformation/Dissolution protocol. The experimental design includes the refinements, agreed by the ad hoc OECD Validation Management Group (VMG), as described in the Standard Operating Procedures prepared by CANM
Deviations:
no
Remarks:
There were no deviations in the actual tests performed.
GLP compliance:
yes
Remarks:
OECD Principles on Good Laboratory Practice (as revised in 1997), ENV/MC/CHEM(98)17
Type of study / information:
The information relates to manganese leaching out of the test substance into environmentally relevant water at pH 6, and provides a concentration of the metal in water after both 7 days (1,10 and 100 mg/L loading) and 28 days (1mg/L loading)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): manganese dioxide
- Physical state: solid

Results and discussion

Any other information on results incl. tables

Manganese dioxide : summary of the results for the 24 h screening tests, 100 mg/L loading at pH 6,7 and 8 with an agitation of 200 RPM

pH 6

Blanks

100 mg/L loading

Time, h

Mn, µg/L   S.D.

Mn, µg/L   S.D.

0

0.0

0.01

2.7

0.35

24

0.0

0.07

21.7

0.55

pH 7

Blanks

100mg/L loading

Time, h

Mn, µg/L   S.D.

Mn, µg/L   S.D.

0

0.4

0.32

0.7

0.13

24

0.6

0.30

0.9

0.20

pH 8

Blanks

100 mg/L loading

Time, h

Mn, µg/L   S.D.

Mn, µg/L   S.D.

0

0.2

0.48

0.4

0.18

24

0.3

0.11

0.4

0.29

Manganese dioxide: summary of the results of transformation / dissolution tests for 7 days at 10 and 100 mg/L loading and 28 days 1mg/L loading, performed at pH 6 with 100 RPM agitation.

 

Blanks

1 mg/L loading

Time, h

Mn, µg/L   S.D.

Mn, µg/L   S.D.

0

0.6

0.29

0.4

0.19

168

1.0

0.36

4.6

0.95

672

0.3

0.13

15.9

1.53

 

Blanks

10 mg/L loading

Time, h

Mn, µg/L   S.D.

Mn, µg/L   S.D.

0

 0.6

 0.56

 1.2

 0.21

168

 0.1

 0.23

 10.5

 0.88

 

Blanks

100 mg/L loading

Time, h

  Mn, µg/L   S.D.

  Mn, µg/L   S.D.

0

 0.6

 0.56

 3.2

 0.64

168

 0.1

 0.23

 47.1

 5.04

Applicant's summary and conclusion

Conclusions:
At test material loading rates of 1, 10 and 100 mg/L, the level of manganese measured in the pH 6 media, following a 7 day exposure period, were 4.6, 10.5 and 47.1 µg/L, respectively. The level of manganese measured in the pH 6 media following 28 days exposure, at the 1 mg/L test material loading rate, was 15.9 µg/L.
The test demonstrates low leaching of Mn from the substance, both for short-term and long-term periods is less than the background concentration of Mn in Europe.
Executive summary:

The extent of transformation/dissolution of Mn from the test substance was investigated in a study which was conducted in accordance with the standardised guideline OECD 29.

A screening test was first conducted to ascertain the pH of maximum metal release. The test substance was introduced into the aqueous media (pH 6, pH 7 and pH 8) at a single loading of 100 mg/L. After 24 hours agitation, the dissolved metal (Mn) ion concentration was measured. The highest level of Mn release was from the pH 6 solution and so the definitive study was conducted at this pH.

In the definitive study, three different test material loading rates were investigated (1, 10 and 100 mg/L). The level of Mn release was measured after a 7 day agitation period for all three loading rates. Furthermore, the level of Mn release was measured after a 28 day agitation period at the 1 mg/L loading rate only.

Under the conditions of the study, the concentrations of manganese in solution following a 7 day agitation period at test substance loading rates of 1, 10 and 100 mg/L were 4.6, 10.5 and 47.1 µg/L, respectively. The level of manganese measured in the pH 6 media following 28 days exposure, at the 1 mg/L test material loading rate, was 15.9 µg/L.

Results of the definitive study demonstrate a low leaching of Mn from manganese dioxide. The concentration after 24 hours and 7 days are both less than the background level in Europe (15.9 -35.8 µg/L) as is the concentration after 28 days.

(see attached background material on probabilistic determination of manganese in Europe)