Cerium vanadium tetraoxide

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04 November 2017 - 13 November 2017

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

Version / remarks:

July 2001

Deviations:

no

GLP compliance:

yes

Remarks:

The analysis was not performed in compliance with GLP principles, but according to the ISO 17025 standard.

Type of method:

other: Transformation/Dissolution Screening

Type of test:

screening transformation/dissolution test - sparingly soluble metal compounds

Mean dissolved conc.:

25 µg/L

Element analysed:

Vanadium

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Test conditions:

pH 6

Type of test:

screening transformation/dissolution test - sparingly soluble metal compounds

Mean dissolved conc.:

41.5 µg/L

Element analysed:

Vanadium

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Test conditions:

pH 8

Details on results:

The following observations were made from the test vessels at the nominal pH 6 with a loading of 100 mg/L test item:
- An average dissolved concentration of 25.0 ± 1.3 μg/L V was found at the 24 hours endpoint with a between-vessel coefficient of variation of 5 % (N = 3) which meets the <20 % quality criteria at the 24 hours endpoint. The within-vessel coefficients of variation meet the <10 % quality criteria for all test vessels. Based on the specific surface area of the test item powder (i.e. 50.7 m²/g), a vanadium release per surface of 0.0049 mg/m² was calculated at the 24 hours endpoint. Based on the vanadium content of the test item (1.61 % V) and the average dissolved vanadium concentration, a vanadium release of approximately 1.6 % could be calculated at the 24 hours endpoint

The following observations were made from the test vessels at the nominal pH 8 with a loading of 100 mg/L test item:
- An average dissolved concentration of 41.5 ± 0.6 μg/L V was found at the 24 hours endpoint with a between-vessel coefficient of variation of 2 % (N = 3) which meets the <20 % quality criteria at the 24 hours endpoint. The within-vessel coefficients of variation meet the <10 % quality criteria for all test vessels. Based on the specific surface area of the test item powder (i.e. 50.7 m²/g), a vanadium release per surface of 0.0082 mg/m² was calculated at the 24 hours endpoint. Based on the vanadium content of the test item (1.61 % V) and the average dissolved vanadium concentration, a vanadium release of approximately 2.6 % could be calculated at the 24 hours endpoint.

Table 1         24-hours Screening test at 100rpm ontest itemat a100mg/L loadingin a standard aqueous medium atpH 6. Data of measured dissolved vanadium concentrations, temperature, pH and dissolved oxygen concentration in test vessels.

 

(BLANK CORRECTED, if the blank value is higher than reporting limit, otherwise blank assumed as 0)

100 mg/L test item pH 6, 100 rpm		µg/L V	T (°C)	pH	DO (mg/L O2)
Accredited reporting limit		0.5
Replica 1	Spl1	25.4	22.4	6.00	8.40
	Spl2	25.4
	Spl3	25.4
	Xavg,1	25.4
	Swithin,1	0.0
	CVwithin,1(%)	0
Replica 2	Spl1	26.1	22.4	5.99	8.42
	Spl2	26.1
	Spl3	26.1
	Xavg,2	26.1
	Swithin,2	0.0
	CVwithin,2(%)	0
Replica 3	Spl1	23.7	22.4	6.00	8.37
	Spl2	23.5
	Spl3	23.5
	Xavg,3	23.6
	Swithin,3	0.1
	CVwithin,3(%)	0
Xavg		25.0
Sbetween		1.3
CVbetween(%)		5
S		1.1
CV		5

xavg,vwithin vessel average of 3 samples where v is the replica test vessel number (N=3)

swithin,vwithin vessel Standard Deviation where v is the replica test vessel number (N=3)

CVwithin,vwithin vessel Coefficient of Variation where v is the replica test vessel number (N=3)

xavgaverage of 3 test vessels (3 samples per test vessel; blank corrected if the blank values are greater

than the reporting limit. Otherwise blank assumed as 0) (N=9)

sbetweenbetween vessel Standard Deviation (N=3)

CVbetweenbetween vessel Coefficient of Variation (N=3)

soverall Standard Deviation (N=9)

CVoverall Coefficient of Variation (N=9)

 

Table 2         24-hours Screening test at 100rpm ontest itemat a100mg/L loadingin a standard aqueous medium atpH 8. Data of measured dissolved vanadium concentrations, temperature, pH and dissolved oxygen concentration in test vessels.

 

(BLANK CORRECTED, if the blank value is higher than reporting limit, otherwise blank assumed as 0)

100 mg/L test item pH 8, 100 rpm		µg/L V	T (°C)	pH	DO (mg/L O2)
Accredited reporting limit		0.5
Replica 1	Spl1	40.3	22.5	8.02	8.37
	Spl2	40.9
	Spl3	41.2
	Xavg,1	40.8
	Swithin,1	0.4
	CVwithin,1(%)	1
Replica 2	Spl1	41.5	22.4	8.03	8.37
	Spl2	42.2
	Spl3	41.7
	Xavg,2	41.8
	Swithin,2	0.4
	CVwithin,2(%)	1
Replica 3	Spl1	42.5	22.5	8.03	8.41
	Spl2	41.7
	Spl3	41.7
	Xavg,3	41.9
	Swithin,3	0.5
	CVwithin,3(%)	1
Xavg		41.5
Sbetween		0.6
CVbetween(%)		2
S		0.7
CV		2

xavg,vwithin vessel average of 3 samples where v is the replica test vessel number (N=3)

swithin,vwithin vessel Standard Deviation where v is the replica test vessel number (N=3)

CVwithin,vwithin vessel Coefficient of Variation where v is the replica test vessel number (N=3)

xavgaverage of 3 test vessels (3 samples per test vessel; blank corrected if the blank values are greater

than the reporting limit. Otherwise blank assumed as 0) (N=9)

sbetweenbetween vessel Standard Deviation (N=3)

CVbetweenbetween vessel Coefficient of Variation (N=3)

soverall Standard Deviation (N=9)

CVoverall Coefficient of Variation (N=9)

Conclusions:

In a 24-hour screening study with a loading rate of 100 mg test item/L, an average vanadium concentration of 25.0 μg/L was measured at pH 6 and an average concentration of 41.5 μg/L was measured at pH 8.

Executive summary:

Brouwers (2018) is a GLP compliant study following OECD guideline 29 and is considered to be reliable without restrictions (Klimisch 1). A 24-hour screening study was conducted with a loading rate of 100 mg/L, at pH 6 and pH 8. Vanadium concentrations were analysed using ICP-MS. The concentration of total organic carbon (TOC) in the medium was <1.0 mg/L C and below the required level of 2.0 mg/L C. This was confirmed by a total organic carbon (TOC) analysis of a 100 mL sample of the 0.2 μm filtered test medium.

 

For vanadium an average concentration of 25.0 μg/L was measured at pH 6. Based on the specific surface area of the test item, a release per surface of 0.0049 mg/m² V was calculated. Based on the vanadium content (1.61 % V) in the test item and the average dissolved vanadium concentrations in the test solutions, a vanadium release of 1.6 % was calculated as the 24 hours endpoint.

 

For vanadium an average concentration of 41.5 μg/L was measured at pH 8. Based on the specific surface area of the test item, a release per surface of 0.0082 mg/m² V was calculated. Based on the vanadium content (1.61 % V) in the test item and the average dissolved vanadium concentrations in the test solutions, a vanadium release of 2.6 % was calculated at the 24 hours endpoint. In conclusion, the screening study demonstrated that the highest release of vanadium from the test item occurs at pH 8.

Reference 2

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

key study

Study period:

30 December 2017 - 21 February 2018

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

Version / remarks:

July 2001

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

The analysis was not conducted to GLP, but according to ISO 17025

Type of method:

other: Transformation/Dissolution Full test

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: IC21424
- Expiration date of the lot/batch: 23-05-2021

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature, in the dark
- Stability under test conditions: Standard test conditions

FORM AS APPLIED IN THE TEST (if different from that of starting material) the test item as received did fulfil the <1 mm size requirements. Therefore, there was no need for further preparation of the test item.

Test item composition:
 20.7 % Aluminium oxide [CAS: 1344-28-1]
 64.9 % Magnesium oxide [CAS: 1309-48-4]
 5.1 % Cerium dioxide [CAS: 1306-38-3]
 1.0 % Diiron trioxide [CAS: 1309-37-1]
 3.6 % Cerium Vanadium oxide [CAS: 13597-19-8]
 1.7 % Magnesium Vanadium oxide [CAS: 13573-13-2]
 1.0 % Calcium Vanadium Oxide [CAS: 14100-64-2]
 2.0 % Water [CAS: 7732-18-5]

Key result

Type of test:

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

Mean dissolved conc.:

7.34 µg/L

Element analysed:

Vanadium

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH 8

Type of test:

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

Mean dissolved conc.:

5.13 µg/L

Element analysed:

Vanadium

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH 8

Details on results:

The following observations were made at pH 8:

An average dissolved vanadium concentration of 5.13 ± 0.26 μg/L V at the 7 day sampling point and 7.34 ± 0.30 μg/L V at the 28 day endpoint was measured with a between-vessel variation of 5 % (N = 3) and 4 % (N = 3) respectively, which met the <20 % quality criteria at the 7 and 28 days endpoints. The within-vessel coefficients of variation met the <10 % quality criteria for all test vessels at the 7 and 28 days endpoints. The dissolution of vanadium could be described by second order kinetic model which is showed in Figure 1b and the subsequent estimated equations.

Based on the average exposed surface area of the the test item (i.e. 50.7 m²/g), a vanadium release per surface of 0.10 mg/m² and 0.14 mg/m² was calculated at the 7 days and 28 days extraction endpoints, respectively.

Based on the average vanadium content in the test item (1.61 %) and the average dissolved vanadium concentrations in the test solution, a vanadium release of 32 % and 46 % was calculated at the 7 days and 28 days endpoints, respectively.

Conclusions:

At a loading rate of 1 mg/L, at pH 8, the average dissolved vanadium concentrations were 5.13 and 7.34 μg/L after 7 and 28 days, respectively.

Executive summary:

Brouwers (2018) is a GLP compliant study following OECD guideline 29 and is considered to be reliable without restrictions (Klimisch 1). The test item was tested at a loading rate of 1 mg/L, for 28 days at pH 8.  The average dissolved vanadium concentrations were 5.13 and 7.34 μg/L after 7 and 28 days, respectively. Based on the average vanadium content of the test item (1.61%), a vanadium release of 32% and 46% was calculated after 7 and 28 days, respectively. Based on the average exposed surface area of the test item (50.7 m2/g) a vanadium release per surface area of 0.10 mg/m² and 0.14 mg/m² was calculated at 7 and 28 days, respectively.

Description of key information

In a 24-hour screening study with a loading rate of 100 mg test item/L, an average vanadium concentration of 25.0 μg/L was measured at pH 6 and an average concentration of 41.5 μg/L was measured at pH 8. The screening study demonstrated that the highest release of vanadium from the test item occurs at pH 8. A 28-day transformation / dissolution study was therefore conducted at pH 8. At a loading rate of 1 mg/L, at pH 8, the average dissolved vanadium concentrations were 5.13 and 7.34 μg/L after 7 and 28 days, respectively.

Additional information

The registered substance is not placed on the market as a discrete substance powder, but as a component in a mixture. Transformation / dissolution testing was therefore conducted with the product as placed on the market as the most realistic scenario.

Brouwers (2018a) is a GLP compliant study following OECD guideline 29 and is considered to be reliable without restrictions (Klimisch 1). A 24-hour screening study was conducted with a loading rate of 100 mg/L, at pH 6 and pH 8. Vanadium concentrations were analysed using ICP-MS.

 

For vanadium an average concentration of 25.0 μg/L was measured at pH 6. Based on the specific surface area of the test item, a release per surface of 0.0049 mg/m² V was calculated. Based on the vanadium content (1.61 % V) in the test item and the average dissolved vanadium concentrations in the test solutions, a vanadium release of 1.6 % was calculated as the 24 hours endpoint. For vanadium an average concentration of 41.5 μg/L was measured at pH 8. Based on the specific surface area of the test item, a release per surface of 0.0082 mg/m² V was calculated. Based on the vanadium content (1.61 % V) in the test item and the average dissolved vanadium concentrations in the test solutions, a vanadium release of 2.6 % was calculated at the 24 hours endpoint. In conclusion, the screening study demonstrated that the highest release of vanadium from the test item occurs at pH 8.

 

Based on the results from the screening study a 28 day transformation / dissolution study was conducted at pH 8. Brouwers (2018b) is a GLP compliant study following OECD guideline 29 and is considered to be reliable without restrictions (Klimisch 1). The test item was tested at a loading rate of 1 mg/L, for 28 days at pH 8.  The average dissolved vanadium concentrations were 5.13 and 7.34 μg/L after 7 and 28 days, respectively. Based on the average vanadium content of the test item (1.61%), a vanadium release of 32% and 46% was calculated after 7 and 28 days, respectively. Based on the average exposed surface area of the test item (50.7 m2/g) a vanadium release per surface area of 0.10 mg/m² and 0.14 mg/m² was calculated at 7 and 28 days, respectively.