Aluminium oxide

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Not reported

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD 105)

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

yes

Type of method:

flask method

Water solubility:

<= 0 g/L

Temp.:

20 °C

pH:

ca. 6 - ca. 7

Table 4.3

Sample No.	Time shaken at 30 C (hr)	Time equilibrated at 20C (hr)	Concentration (g/L)	pH
1	24	24	≤ 0.00002	6.8
2	48	24	≤ 0.00002	6.8
3	72	24	≤ 0.00002	6.8

mean concentration = 0.00002 g/L at 20 deg C

ICP analysis table from BLL:

BLL ref No.	Sample ID	Al mg/L
BL-11-0535-09	Sample 1A	0.02
BL-11-0536-09	Sample 1B	0.02
BL-11-0537-09	Sample 2A	0.02
BL-11-0538-09	Sample 2B	0.02
BL-11-0539-09	Sample 3A	0.02
BL-11-0540-09	Sample 3B	0.02
BL-11-0541-09	Blank A	0.02
BL-11-0542-09	Blank B	0.01

Per Appendix 1 page 3 (Walker JA, Butterworth Laboratories, BLL report No 0911-0058):

Reference items: 1000 ppm stock aluminum standard supplied by Romil, Product E3AL6 Lot L546487 and 10000 ppm aluminum stock supplied by Romil, Product N7AL6 Lot E534457

In house method BLM55G issue 17. Discussion of ICP results: instrument was calibrated over range 0.1 to 10 mg/L. A 1 ppm QC check standard was run at the end of the sequence. Results for this standard fell within 95 -105% of target. In-house duplicate tests were not performed as duplicate sampes were prepared prior to receipt. Limit of detection was assessed by preparing a standard at 0.01 mg/L. The readings were made that generated a mean of 0.008 mg/L with a 5% RSD. The theoretical limit of detection was estimated at 0.004 mg/L (10X std dev). Based on this data, a reporting limit of 0.01 mg/L was considered acceptable.

Conclusions:

The water solubility of aluminum oxide as determined by the OECD Guideline 105 was <0.00002 g/L, which is insoluble.

Executive summary:

The water solubility of aluminum oxide was less than or equal to 2x10-5 g/L of solution at 20.0 +/- 0.05 degrees C, withing the pH range 6 to 7 in accordance with the flask method, of the OECD Guidelines for Testing of Chemicals. Aluminum oxide is insoluble.

Reference 2

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2007-03

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

GLP compliance:

yes

Type of method:

flask method

Type of test:

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

Mean dissolved conc.:

2 µg/L

Element analysed:

Al

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH6 (pH6.04 to pH6.35)
temperature: 20.3 °C to 23.1 °C
dissolved oxygen concentration 7.19 mg/L to 8.37 mg/L O2

Remarks on result:

other: St. Dev. 0, CV 0%

Type of test:

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

Mean dissolved conc.:

2 µg/L

Element analysed:

Al

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Test conditions:

pH6 (pH6.04 to pH6.35)
temperature: 20.3 °C to 23.1 °C
dissolved oxygen concentration: 7.19 mg/L to 8.37 mg/L O2

Remarks on result:

other: St. Dev. 1.67, CV 71%

Type of test:

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

Mean dissolved conc.:

5 µg/L

Element analysed:

Al

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH6 (pH6.04 to pH6.35)
temperature: 20.3 °C to 23.1 °C
dissolved oxygen concentration: 7.19 mg/L to 8.37 mg/L O2

Remarks on result:

other: St. Dev. 3.40, CV 67%

Type of test:

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

Mean dissolved conc.:

6 µg/L

Element analysed:

Al

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH8 (pH7.63 to pH8.07)
temperature: 18.8 °C to 24.0 °C
dissolved oxygen concentration 7.19 mg/L to 8.37 mg/L O2

Remarks on result:

other: St. Dev. 0.49, CV 8%

Type of test:

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

Mean dissolved conc.:

82 µg/L

Element analysed:

Al

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Test conditions:

pH8 (pH7.63 to pH8.20)
temperature: 18.8 °C to 24.0 °C
dissolved oxygen concentration 7.19 mg/L to 8.37 mg/L O2

Remarks on result:

other: St. Dev. 12.64, CV 15%

Type of test:

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

Mean dissolved conc.:

4 µg/L

Element analysed:

Al

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH8 (pH7.63 to pH8.20)
temperature: 18.8 °C to 24.0 °C
dissolved oxygen concentration 7.19 mg/L to 8.37 mg/L O2

Remarks on result:

other: St. Dev. 1.27, CV 35%

Dissolution Transformation Results at pH 6.0

At pH 6 Aluminium Oxide, in all tested condition, showed very low release of dissolved metal.

The amounts of metal released by the samples and the blanks were undistinguishable.

 

					Aluminium, μg/L
Blanks	Time, hr	Temp.,°C	O2, mg/L	pH	Mean	St. Dev.	CV, %
	0	20.3	8.31	6.17	2	0.00	0
	2	21.0	7.84	6.27	2	1.24	57
	6	21.1	7.72	6.22	2	0.00	0
	24	21.2	8.02	6.04	3	1.07	40
	48	21.8	8.01	6.20	2	0.00	0
	96	23.0	7.86	6.09	2	0.00	0
	168	22.6	7.64	6.10	2	0.00	0
	336	22.1	7.81	6.18	2	1.56	63
	504	23.1	7.89	6.24	4	3.06	68
	672	22.6	7.94	6.13	3	0.89	30
Al2O3 1 mg/L	0	20.3	8.31	6.17	2	1.21	56
	2	21.0	7.84	6.27	2	0.65	37
	6	21.1	7.72	6.22	3	1.63	64
	24	21.2	8.02	6.04	2	0.64	36
	48	21.8	8.01	6.20	2	0.96	51
	96	23.0	7.86	6.09	2	0.00	0
	168	22.6	7.64	6.10	2	0.00	0
	336	22.1	7.81	6.18	5	2.62	51
	504	23.1	7.89	6.24	4	1.95	48
	672	22.6	7.94	6.13	5	3.40	67
Al2O3 100 mg/L	0	20.3	8.31	6.17	6	1.72	29
	2	21.0	7.84	6.27	4	1.46	39
	6	21.1	7.72	6.22	2	0.00	0
	24	21.2	8.02	6.04	4	1.14	28
	48	21.8	8.01	6.20	2	1.09	45
	96	23.0	7.86	6.09	3	2.47	97
	168	22.6	7.64	6.10	2	1.67	71

Dissolution Transformation Results at pH 8.0

Aluminium oxide at pH 8.0, low loading, showed a small amount of metal released at 48h (twice the amount found in the blanks). At 100 mg/L loading, aluminium oxide released dissolved metal in a biphasic kinetics, a fast increase reaching a maximum at 48h (113 μg/L) and a slow decrease phase reaching 82 μg/L at day 7.

 

					Aluminium, μg/L
Blanks	Time, hr	Temp.,°C	O2, mg/L	pH	Mean	St. Dev.	CV, %
	0	22.0	8.24	7.85	3	1.05	31
	2	22.5	7.95	7.86	3	0.00	0
	6	22.8	7.19	7.96	3	0.00	0
	24	23.6	7.75	7.96	3	0.00	0
	48	24.0	7.63	7.83	3	0.43	13
	96	23.0	7.86	8.07	3	0.00	0
	168	22.8	7.82	7.98	3	0.00	0
	336	22.7	7.78	7.92	3	1.04	31
	504	23.4	7.75	7.85	3	0.00	0
	672	22.9	7.86	7.83	3	0.92	27
Al2O3 1 mg/L	0	22.0	8.24	7.85	3	0.60	18
	2	22.5	7.95	7.86	3	0.47	15
	6	22.8	7.19	7.96	3	0.00	0
	24	23.6	7.75	7.96	5	1.32	29
	48	24.0	7.63	7.83	4	1.21	33
	96	23.0	7.86	8.07	6	1.01	17
	168	22.8	7.82	7.98	6	0.49	8
	336	22.7	7.78	7.92	4	1.03	29
	504	23.4	7.75	7.85	3	0.00	0
	672	22.9	7.86	7.83	4	1.27	35

 

					Aluminium, μg/L
Blanks	Time, hr	Temp.,°C	O2, mg/L	pH	Mean	St. Dev.	CV, %
	0	18.8	8.35	7.96	3	0.00	0
	2	19.7	8.20	8.00	8	2.85	37
	6	20.7	8.37	8.01	5	3.88	78
	24	23.3	7.44	8.00	4	2.62	67
	48	22.5	7.69	7.89	8	0.65	9
	96	22.8	7.78	7.92	4	1.31	36
	168	22.6	7.72	7.94	3	0.00	0
Al2O3 100 mg/L	0	18.8	8.35	7.96	3	0.64	19
	2	19.7	8.20	8.00	9	2.31	27
	6	20.7	8.37	8.01	11	3.26	30
	24	23.3	7.44	8.00	57	9.60	17
	48	22.5	7.69	7.89	113	9.23	8
	96	22.8	7.78	7.92	87	7.61	9
	168	22.6	7.72	7.94	82	12.64	15

 

 

Reference 3

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Not reported

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Although sufficient experimental details are not provided, the reference is a peer reviewed handbook and is considered reliable with restrictions

Qualifier:

no guideline followed

Principles of method if other than guideline:

Details of the guideline followed to determine the result are not provided.

GLP compliance:

not specified

Type of method:

other: No information available

Water solubility:

0 g/L

Remarks on result:

other: No details on temperature or pH provided.

Details on results:

Insoluble in water

Insoluble

Executive summary:

Aluminium oxide is insoluble in water

Description of key information

<0.00002 g/L at 20 °C and pH 6 to 7 (OECD 105)

Additionally a study on Transformation/Dissolution according to the OECD Series on Testing and Assessment No. 29 was performed on the bulk form of the substance.

During the study on the bulk sample at a loading of 1 mg/L to the standard medium at pH8, it was shown that 4 µg/L was released at 48 h. It was also shown:

An average dissolved aluminium concentration of 6 µg/L Al was found after 7 days of exposure.
An average dissolved aluminium concentration of 4 µg/L Al was found after 28 days of exposure.

At 100 mg/L loading to the standard medium at pH8, aluminium oxide released dissolved metal in a biphasic kinetics, a fast increase reaching a maximum at 48 h (113 μg/L) and a slow decrease phase reaching 82 μg/L at day 7.

During the study on the bulk sample at pH6, it was shown that in all tested condition very low release of dissolved metal.

The amounts of metal released by the samples and the blanks were undistinguishable.

Key value for chemical safety assessment

Water solubility:

0 g/L

at the temperature of:

20 °C

Additional information

Data from the key study conducted in 2010, and handbook data agree that the water solubility of aluminum oxide is very low (0.00002 g/L at 20 °C).