Barium oxide (BaO), solid soln. with calcium oxide, magnesium oxide, phosphorus oxide (P2O5), strontium oxide and zinc oxide, copper-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:

27 May 2016 to 05 July 2016

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

Qualifier:

according to guideline

Guideline:

other: EEC guideline SANCO/3029/99 rev. 4 dated 11/07/00: Working document “Guidance for generating and reporting methods of analysis in support of residue data requirements for Annex II (part A, Section 4) and Annex III (part A, Section 5)

GLP compliance:

yes (incl. QA statement)

Type of method:

other: Transformation / dissolution test

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature without particular precaution to avoid the light exposure

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: None
- Final preparation of a solid: 1 mg of test item was added to the test medium

Type of test:

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

Mean dissolved conc.:

17.37 µg/L

Element analysed:

copper

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

test medium pH 6, room temperature

Remarks on result:

other: SD = 1.10 µg/L

Type of test:

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

Mean dissolved conc.:

17.68 µg/L

Element analysed:

copper

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

test medium pH 6, room temperature

Remarks on result:

other: SD = 0.91 µg/L

Type of test:

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

Mean dissolved conc.:

18.03 µg/L

Element analysed:

copper

Loading of aqueous phase:

1 mg/L

Incubation duration:

14 d

Test conditions:

test medium pH 6, room temperature

Remarks on result:

other: SD = 0.60 µg/L

Type of test:

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

Mean dissolved conc.:

20.91 µg/L

Element analysed:

copper

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

Test medium pH 6, room temperature

Remarks on result:

other: SD = 1.45 µg/L

Type of test:

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

Mean dissolved conc.:

5.44 µg/L

Element analysed:

copper

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

Test medium pH 8, room temperature

Remarks on result:

other: SD = 0.50 µg/L

Type of test:

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

Mean dissolved conc.:

1.82 µg/L

Element analysed:

copper

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

Test medium pH 8, room temperature

Remarks on result:

other: SD = 0.02 µg/L

Type of test:

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

Mean dissolved conc.:

1.46 µg/L

Element analysed:

copper

Loading of aqueous phase:

1 mg/L

Incubation duration:

14 d

Test conditions:

Test medium pH 8, room temperature

Remarks on result:

other: SD = 0.15 µg/L

Type of test:

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

Mean dissolved conc.:

1.38 µg/L

Element analysed:

copper

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

Test medium pH 8, room temperature

Remarks on result:

other: SD = 0.12 µg/L

Type of test:

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

Mean dissolved conc.:

429 µg/L

Element analysed:

strontium

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

Test medium pH 6, room temperature

Remarks on result:

other: SD = 22 μg/L

Type of test:

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

Mean dissolved conc.:

444 µg/L

Element analysed:

strontium

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

Test medium pH 6, room temperature

Remarks on result:

other: SD = 37 μg/L

Type of test:

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

Mean dissolved conc.:

445 µg/L

Element analysed:

strontium

Loading of aqueous phase:

1 mg/L

Incubation duration:

14 d

Test conditions:

Test medium pH 6, room temperature

Remarks on result:

other: SD = 18 μg/L

Type of test:

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

Mean dissolved conc.:

449 µg/L

Element analysed:

strontium

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

Test medium pH 6, room temperature

Remarks on result:

other: SD = 8 μg/L

Type of test:

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

Mean dissolved conc.:

44.23 µg/L

Element analysed:

strontium

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

Test medium pH 8, room temperature

Remarks on result:

other: SD = 2.83 μg/L

Type of test:

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

Mean dissolved conc.:

53.89 µg/L

Element analysed:

strontium

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

Test medium pH 8, room temperature

Remarks on result:

other: SD = 1.58 μg/L

Type of test:

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

Mean dissolved conc.:

54.1 µg/L

Element analysed:

strontium

Loading of aqueous phase:

1 mg/L

Incubation duration:

14 d

Test conditions:

Test medium pH 8, room temperature

Remarks on result:

other: SD = 2.83 μg/L

Type of test:

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

Mean dissolved conc.:

56.54 µg/L

Element analysed:

strontium

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

Test medium pH 8, room temperature

Remarks on result:

other: SD = 1.93 μg/L

Details on results:

After 28 days, 20.91 µg/L of copper and 449 µg/L of strontium had been released from the test item at pH 6. In test medium at pH 8, 1.38 µg/L of copper and 56.54 µg/L of strontium had been released after 28 days. Considering an initial Strontium apatite, copper doped load of 1 mg/L and the maximum possible release of 27.80 µg/L for copper and 585.26 µg/L for strontium (calculated from the test item composition), release of the metals in the test medium at pH 6 is high, and release of the metals is lower in the test medium at pH 8. A slow decrease of copper released from the test item was observed during the test (from 5.75 µg/L after 2 hours to 1.38 µg/L after 28 days). The decrease of copper during the test is probably due to oxidizing processes or adsorption to experimental materials.

TABLE 1a Summary table: Strontium apatite, copper doped 28-day full test with a loading of 1 mg/L at pH6 for Copper

 

Full test 28 days at 1 mg/L pH 6 2926584-001		^63Cu (µg/L)	Full test 28 days at 1 mg/L pH 6 2926584-001		^63Cu (µg/L)
Test medium pH 6 T0 hour	Mean	n.d.	Test medium pH 6 T7 days	Mean	17.68
	S.D.	-		S.D.	0.91
	RSD%	-		RSD%	5.12
Test medium pH 6 T2 hours	Mean	15.18	Test medium pH 6 T14 days	Mean	18.03
	S.D.	0.40		S.D.	0.60
	RSD%	2.64		RSD%	3.30
Test medium pH 6 T6 hours	Mean	16.73	Test medium pH 6 T21 days	Mean	18.83
	S.D.	0.93		S.D.	0.65
	RSD%	5.53		RSD%	3.43
Test medium pH 6 T24 hours	Mean	17.37	Test medium pH 6 T28 days	Mean	20.91
	S.D.	1.10		S.D.	1.45
	RSD%	6.33		RSD%	6.95
Test medium pH 6 T4 days	Mean	17.44	-
	S.D.	1.25
	RSD%	7.16

n.d.: lower than the Limit of Detection (L.O.D. = 0.50 µg/L for Cu).

 The between-vessel variation was less than 20% recommended by OECD Series No. 29.

 

TABLE 1b Summary table: Strontium apatite, copper doped 28-day full test with a loading of 1 mg/L at pH8 for Copper

 

Full test 28 days at 1 mg/L pH 8 2926584-001		^63Cu (µg/L)	Full test 28 days at 1 mg/L pH 8 2926584-001		^63Cu (µg/L)
Test medium pH 8 T0 hour	Mean	n.d.	Test medium pH 8 T7 days	Mean	1.82
	S.D.	-		S.D.	0.02
	RSD%	-		RSD%	0.70
Test medium pH 8 T2 hours	Mean	5.75	Test medium pH 8 T14 days	Mean	1.46
	S.D.	0.20		S.D.	0.15
	RSD%	3.50		RSD%	10.07
Test medium pH 8 T6 hours	Mean	5.66	Test medium pH 8 T21 days	Mean	1.43
	S.D.	0.28		S.D.	0.04
	RSD%	5.00		RSD%	2.89
Test medium pH 8 T24 hours	Mean	5.44	Test medium pH 8 T28 days	Mean	1.38
	S.D.	0.50		S.D.	0.12
	RSD%	9.21		RSD%	8.73
Test medium pH 8 T4 days	Mean	2.54	-
	S.D.	0.02
	RSD%	0.70

n.d.: lower than the Limit of Detection (L.O.D. = 0.50 µg/L for Cu).

The between-vessel variation was less than 20% recommended by OECD Series No. 29.

  

TABLE 1c Summary table: Strontium apatite, copper doped 28-day full test with a loading of 1 mg/L at pH6 for Strontium

 

Full test 28 days at 1 mg/L pH 6 2926584-001		^88Sr (µg/L)	Full test 28 days at 1 mg/L pH 6 2926584-001		^88Sr (µg/L)
Test medium pH 6 T0 hour	Mean	n.d.	Test medium pH 6 T7 days	Mean	444
	S.D.	-		S.D.	37
	RSD%	-		RSD%	8.36
Test medium pH 6 T2 hours	Mean	384	Test medium pH 6 T14 days	Mean	445
	S.D.	14		S.D.	18
	RSD%	3.74		RSD%	4.05
Test medium pH 6 T6 hours	Mean	401	Test medium pH 6 T21 days	Mean	446
	S.D.	32		S.D.	17
	RSD%	7.99		RSD%	3.77
Test medium pH 6 T24 hours	Mean	429	Test medium pH 6 T28 days	Mean	449
	S.D.	22		S.D.	8
	RSD%	5.17		RSD%	1.82
Test medium pH 6 T4 days	Mean	431	-
	S.D.	32
	RSD%	7.48

n.d.: lower than the Limit of Detection (L.O.D. = 0.50 µg/L for Sr).

The between-vessel variation was less than 20% recommended by OECD Series No. 29.

TABLE 1d Summary table: Strontium apatite, copper doped 28-day full test with a loading of 1 mg/L at pH8 for Strontium

 

Full test 28 days at 1 mg/L pH 8 2926584-001		^88Sr (µg/L)	Full test 28 days at 1 mg/L pH 8 2926584-001		^88Sr (µg/L)
Test medium pH 8 T0 hour	Mean	4.60	Test medium pH 8 T7 days	Mean	53.89
	S.D.	0.09		S.D.	1.58
	RSD%	1.86		RSD%	2.94
Test medium pH 8 T2 hours	Mean	41.97	Test medium pH 8 T14 days	Mean	54.10
	S.D.	1.76		S.D.	2.83
	RSD%	4.19		RSD%	5.22
Test medium pH 8 T6 hours	Mean	42.86	Test medium pH 8 T21 days	Mean	55.53
	S.D.	1.28		S.D.	2.95
	RSD%	2.98		RSD%	5.30
Test medium pH 8 T24 hours	Mean	44.23	Test medium pH 8 T28 days	Mean	56.54
	S.D.	2.83		S.D.	1.93
	RSD%	6.39		RSD%	3.42
Test medium pH 8 T4 days	Mean	46.42	-
	S.D.	1.15
	RSD%	2.49

 

The between-vessel variation was less than 20% recommended by OECD Series No. 29.

 

 

Conclusions:

After 28 days, 20.91 µg/L of copper and 449 µg/L of strontium had been released from the test item at pH 6. In test medium at pH 8, 1.38 µg/L of copper and 56.54 µg/L of strontium had been released after 28 days. Release of the metals is higher at pH 6 compared to pH 8. A slow decrease of copper released from the test item was observed during the test in the test medium at pH 8 (from 5.75 µg/L after 2 hours to 1.38 µg/L after 28 days).

Executive summary:

The transformation/dissolution test with strontium apatite, copper doped was conducted at a loading rate of 1 mg/L in two aqueous media at pH 6 and pH 8 (Pardo Martinez 2016). The study was performed according to the OECD 29 guideline and is a GLP-compliant. This study is considered reliable without restrictions (Klimisch 1) and is suitable for use as a key study for this endpoint.

 After 28 days, 20.91 µg/L of copper and 449 µg/L of strontium had been released from the test item at pH 6 and 1.38 µg/L of copper and 56.54 µg/L of strontium at pH 8. Considering an initial load of 1 mg/L and a maximum possible release calculated from the test item composition, the test results indicate that release of the metals is high in test medium at pH 6 whereas release is lower in test medium at pH 8. A decrease in the amount of copper released during the test was observed (from 5.75 µg/L after 2 hours to 1.38 µg/L after 28 days). The decrease of copper concentration in the test medium at pH 8 during the test is probably due to the oxidizing process or adsorption to the experimental materials.

Description of key information

After 28 days, 20.91 µg/L of copper and 449 µg/L of strontium had been released from the test item at pH 6. In test medium at pH 8, 1.38 µg/L of copper and 56.54 µg/L of strontium had been released after 28 days. Release of the metals is higher at pH 6 compared to pH 8. A slow decrease of copper released from the test item was observed during the test in the test medium at pH 8 (from 5.75 µg/L after 2 hours to 1.38 µg/L after 28 days).

Additional information

The transformation/dissolution test with Strontium apatite, copper doped was conducted at a loading rate of 1 mg/L in two aqueous media at pH 6 and pH 8 (Pardo Martinez 2016). The study was performed according to the OECD 29 guideline and is a GLP-compliant. This study is considered reliable without restrictions (Klimisch 1) and is suitable for use as a key study for this endpoint.

After 28 days, 20.91 µg/L of copper and 449 µg/L of strontium had been released from the test item at pH 6 and 1.38 µg/L of copper and 56.54 µg/L of strontium at pH 8. Considering an initial load of 1 mg/L and a maximum possible release calculated from the test item composition, the test results indicate that release of the metals is high in test medium at pH 6 whereas release is lower in test medium at pH 8. A decrease in the amount of copper released during the test was observed (from 5.75 µg/L after 2 hours to 1.38 µg/L after 28 days). The decrease of copper concentration in the test medium at pH 8 during the test is probably due to the oxidizing process or adsorption to the experimental materials.