Zirconium oxide, hafnium and ytterbium doped

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

Study period:

2017-11-13 to 2018-01-15

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:

no

Type of method:

flask method

Type of test:

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

Element analysed:

Zr

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH 8, ca. 22 °C

Remarks on result:

not determinable because of methodological limitations

Type of test:

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

Element analysed:

Zr

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH 8, ca. 22 °C

Remarks on result:

not determinable because of methodological limitations

Type of test:

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

Element analysed:

Zr

Loading of aqueous phase:

10 mg/L

Incubation duration:

7 d

Test conditions:

pH 8, ca. 22 °C

Remarks on result:

not determinable because of methodological limitations

Type of test:

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

Element analysed:

Zr

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Test conditions:

pH 8, ca. 22 °C

Remarks on result:

not determinable because of methodological limitations

Type of test:

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

Element analysed:

Yb

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH 8, ca. 22 °C

Remarks on result:

not determinable because of methodological limitations

Type of test:

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

Element analysed:

Yb

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH 8, ca. 22 °C

Remarks on result:

not determinable because of methodological limitations

Type of test:

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

Mean dissolved conc.:

0.011 µg/L

Element analysed:

Yb

Loading of aqueous phase:

10 mg/L

Incubation duration:

7 d

Test conditions:

pH 8, ca. 22 °C

Type of test:

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

Mean dissolved conc.:

0.069 µg/L

Element analysed:

Yb

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Test conditions:

pH 8, ca. 22 °C

Type of test:

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

Element analysed:

Hf

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH 8, ca. 22 °C

Remarks on result:

not determinable because of methodological limitations

Type of test:

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

Element analysed:

Hf

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH 8, ca. 22 °C

Remarks on result:

not determinable because of methodological limitations

Type of test:

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

Element analysed:

Hf

Loading of aqueous phase:

10 mg/L

Incubation duration:

7 d

Test conditions:

pH 8, ca. 22 °C

Remarks on result:

not determinable because of methodological limitations

Type of test:

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

Element analysed:

Hf

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Test conditions:

pH 8, ca. 22 °C

Remarks on result:

not determinable because of methodological limitations

Conclusions:

Transformation / dissolution (T/D) of Zirconium oxide, hafnium and ytterbium doped, in powder form, was performed at the pH of maximum dissolution, selected from the results of a 24 hour screening test at pH 6, 7 and 8. Only ytterbium release was detected above the method detection limit (MDL) at the three pH values tested, and specifically, pH 8 presents the maximum dissolution. An average metal release of 0.069 µg/L was measured after 7 days with T/D protocol at 100 mg/L mass loading. Also, an average value of 0.011 µg/L was measured after the 7 day test at 10 mg/L mass loading.

Executive summary:

Transformation / dissolution (T/D) of Zirconium oxide, hafnium and ytterbium doped, in powder form, was performed at the pH of maximum dissolution, selected from the results of a 24 hour screening test at pH 6, 7 and 8. Only ytterbium release was detected above the method detection limit (MDL) at the three pH values tested, and specifically, pH 8 presents the maximum dissolution.  An average metal release of 0.069 µg/L was measured after 7 days with T/D protocol at 100 mg/L mass loading. Also, an average value of 0.011 µg/L was measured after the 7 days test at 10 mg/L mass loading.

Description of key information

Transformation / dissolution (T/D) of Zirconium oxide, hafnium and ytterbium doped, in powder form, was performed at the pH of maximum dissolution, selected from the results of a 24 hour screening test at pH 6, 7 and 8. Only ytterbium release was detected above the method detection limit (MDL) at the three pH values tested, and specifically, pH 8 presents the maximum dissolution.  An average metal release of 0.069 µg/L was measured after 7 days with T/D protocol at 100 mg/L mass loading. Also, an average value of 0.011 µg/L was measured after the 7 day test at 10 mg/L mass loading.

Key value for chemical safety assessment

Water solubility:

0.07 µg/L

at the temperature of:

22 °C