Pentaboron sodium octaoxide

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04/06/2010 to 30/06/2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

other: British Standard Method BS 5688 Part 8.

Deviations:

not specified

GLP compliance:

yes

Type of method:

flask method

Water solubility:

11.73 other: % w/w

Conc. based on:

test mat.

Loading of aqueous phase:

250.3 g/L

Incubation duration:

24 h

Temp.:

20 °C

pH:

>= 6.57 - <= 6.75

Remarks on result:

other: the mean water solubility for the sodium pentaborate granular test item is 2.21% w/w as sodium oxide and 11.73% w/w as boric oxide.

Water solubility:

22.1 g/L

Conc. based on:

test mat.

Loading of aqueous phase:

250.3 g/L

Incubation duration:

24 h

Temp.:

20 °C

pH:

>= 6.57 - <= 6.75

Remarks on result:

other: Calculated based on the measured weight% assuming a density of 1 g/mL

Water solubility:

2.21 other: % w/w

Conc. based on:

test mat.

Loading of aqueous phase:

250.3 g/L

Incubation duration:

24 h

Temp.:

20 °C

pH:

>= 6.57 - <= 6.75

Remarks on result:

other: the mean water solubility for the sodium pentaborate granular test item is 2.21% w/w as sodium oxide and 11.73% w/w as boric oxide.

Details on results:

Based on the preliminary test the water solubility of the test item was from 50 – 100 g/L. The MSDS for the test item stated that the water solubility was 75 g/L at 10°C which is within this range; however as the value stated is at 10°C and the test was carried out at 20°C a higher solubility was expected so the higher end of the preliminary test range, 100 g/L was used. The amount of test item required for 1 L of water would be 5 x 100 = 500 g and as this test is done in triplicate the total amount of test item is 500 x 3 = 1500 g. However based on the approximate amount of test item available the maximum weight of test item available for each replicate was 25 g. Based on the preliminary estimate of solubility of 100 g/L then the amount of water required for 25 g of test item would be:

(25/5)/100 x1000 = 50 mL

Approximately 25 g of test item was then accurately weighed into each of three flasks, 50 mL of distilled water was added to each and the flasks were then placed in a temperature controlled shaker at 30°C.

Prelimiary test:

Weight of test item used: 0.1003 g

Temperature of test: 20 °C

Total Volume of distilled water added (mL)	0.1	0.5	1	2	10	100	>100
Was test item totally dissolved? (y/n)	No	No	No	Yes	N/A	N/A	N/A
Approximate solubility (g/L)	> 1000	1000 - 200	200 - 100	100 - 50	50 - 10	10 - 1	< 1

Shake flask details:

Replicate Number	Weight of test item used (g)	Volume of distilled water added (mL)	Number of days shaking	pH of aqueous solution after shaking, 24 hours in 20°C water bath and centrifugation and filtration*
Replicate 1	25.0644	50	1	6.57
Replicate 2	25.0140	50	2	6.63
Replicate 3	25.0040	50	3	6.75

Conclusions:

The results show that the mean water solubility for the sodium pentaborate granular test item is 2.21% w/w as sodium oxide and 11.73% w/w as boric oxide.

Executive summary:

The water solubility was analysed following EU Method A.6 under GLP comliance. Flask method was used. The results show that the mean water solubility for the test item is 2.21% w/w (22.1 g/L assuming a density of 1g/mL ) as sodium oxide and 11.73% w/w as boric oxide.

Description of key information

The water solubility was analysed following EU Method A.6 under GLP compliance. Flask method was used. The results show that the mean water solubility for the test item is 2.21% w/w (22.1 g/L assuming a density of 1 g/mL) as sodium oxide and 11.73% w/w as boric oxide.

Key value for chemical safety assessment

Water solubility:

22.1 g/L