Reaction mass of zinc oxide and zinc peroxide

Water solubility

Link to relevant study record(s)

Reference

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

other: transformation/dissolution test

Type of test:

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

Mean dissolved conc.:

200.02 µg/L

Element analysed:

Zn

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH 8

Remarks on result:

other: with background correction

Type of test:

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

Mean dissolved conc.:

143.05 µg/L

Element analysed:

Zn

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH 8

Remarks on result:

other: with background correction

Type of test:

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

Mean dissolved conc.:

985.15 µg/L

Element analysed:

Zn

Loading of aqueous phase:

10 mg/L

Incubation duration:

7 d

Test conditions:

pH 8

Type of test:

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

Mean dissolved conc.:

1 380.62 µg/L

Element analysed:

Zn

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Test conditions:

pH 8

Details on results:

Mass balances
The recovery of Zn was 108.9 – 121.3 % for the loading of 1 mg/L. The recovery which is not within the limits of 100 ± 15 % is probably due to contamination with ubiquitous Zn.
The recoveries of Zn for the loadings of 10 and 100 mg/L were 94.5 – 97.3 % and 104.4 – 108.0 %, respectively.

dissolved mean concentrations after 7 d and 28 d at pH 8

	7 d	28 d
Zn [µg/L] loading 1 mg/L without background correction	145.39 ± 10.65	202.78 ± 18.15
Zn [µg/L] loading 1 mg/L with background correction	143.05 ± 10.65	200.02 ± 18.15
Zn [µg/L] loading 10 mg/L	985.19 ± 23.97
Zn [µg/L] loading 100 mg/L	1380.62 ± 114.35
Peroxide [µg/L] mg/L loading 1 mg/L	< 30
Peroxide [µg/L] mg/L loading 10 mg/L	< 30
Peroxide [µg/L] mg/L loading 100 mg/L	70 ± 10

 

Executive summary:

A transformation/dissolution test for Zinc peroxide was conducted with a loading of 1, 10 and 100 mg/L over 7 days with samplings after 0 h (directly after introducing the test item), 2 h, 6 h, 1 d, 4 d, and 7 d. Samplings with the loading of 1 mg/L were additionally conducted after 14 d, 21 d and 28 d according to the guidance document. Dissolved concentrations of zinc were quantified by ICP-OES.

Dissolved peroxide concentrations were quantified after 0 h, 2 h, 6 h, 1 d, 4 d, 7d using a commercially available peroxide testing kit (Macherey-Nagel, Dueren, Germany) applying a photometric method only once per vessel and sampling time.

Test was performed in triplicate vessels (agitation at 100 rpm, 21.5 ± 1.5 °C) and duplicate samples per vessel, this includes method blanks (same procedure but without test item).

Oxygen levels (8.18 – 8.49 ppm) as well as the mean temperatures are in compliance with the requirements of the OECD guidance document 29.

In solutions containing 1, 10 and 100 mg/L of the test item and in method blanks at pH 8, the pH was in the range of 7.5 – 8.5.

Dissolved mean concentrations after 7 d and 28 d at pH 8

	7 d	28 d
Zn [µg/L] loading 1 mg/L without background correction	145.39 ± 10.65	202.78 ± 18.15
Zn [µg/L] loading 1 mg/L with background correction	143.05 ± 10.65	200.02 ± 18.15
Zn [µg/L] loading 10 mg/L	985.19 ± 23.97
Zn [µg/L] loading 100 mg/L	1380.62 ± 114.35
Peroxide [µg/L] mg/L loading 1 mg/L	< 30
Peroxide [µg/L] mg/L loading 10 mg/L	< 30
Peroxide [µg/L] mg/L loading 100 mg/L	70 ± 10

Description of key information

1380 µg Zn/L (full transformation dissolution test)

Key value for chemical safety assessment

Water solubility:

1.38 mg/L

at the temperature of:

21.3 °C

Additional information

A transformation/dissolutiontest for Zinc peroxide was conducted with a loading of 1, 10 and 100 mg/L over 7 days with samplings after 0 h (directly after introducing the test item), 2 h, 6 h, 1 d, 4 d, and 7 d. Samplings with the loading of 1 mg/L were additionally conducted after 14 d, 21 d and 28 d according to the guidance document. Dissolved concentrations of zinc were quantified by ICP-OES.

Dissolved peroxide concentrations were quantified after 0 h, 2 h, 6 h, 1 d, 4 d, 7d using a commercially available peroxide testing kit (Macherey-Nagel, Dueren, Germany) applying a photometric method only once per vessel and sampling time.

Test was performed in triplicate vessels (agitation at 100 rpm, 21.5 ± 1.5 °C) and duplicate samples per vessel, this includes method blanks (same procedure but without test item).

Oxygen levels (8.18 – 8.49 ppm) as well as the mean temperatures are in compliance with the requirements of the OECD guidance document 29.

In solutions containing 1, 10 and 100 mg/L of the test item and in method blanks at pH 8, the pH was in the range of 7.5 – 8.5.

Dissolved mean concentrations after 7 d and 28 d at pH 8

	7 d	28 d
Zn [µg/L] loading 1 mg/L without background correction	145.39 ± 10.65	202.78 ± 18.15
Zn [µg/L] loading 1 mg/L with background correction	143.05 ± 10.65	200.02 ± 18.15
Zn [µg/L] loading 10 mg/L	985.19 ± 23.97
Zn [µg/L] loading 100 mg/L	1380.62 ± 114.35
Peroxide [µg/L] mg/L loading 1 mg/L	< 30
Peroxide [µg/L] mg/L loading 10 mg/L	< 30
Peroxide [µg/L] mg/L loading 100 mg/L	70 ± 10