Triboron trimethyl hexaoxide

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Data waiving:

study technically not feasible

Justification for data waiving:

the study does not need to be conducted because the substance is hydrolytically unstable at pH 4, 7 and 9 (half-life less than 12 hours)

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Peer reviewed data base.

Guideline:

other: no data

GLP compliance:

not specified

Type of method:

other: no data

Water solubility:

>= 1 000 g/L

Temp.:

20 °C

Remarks on result:

other: value from secondary database

Details on results:

The water solubility value has been obtained from a secondary literature source which did not list the temperature or pH of the test system.

Methanol is completely miscible in water at 20°C.

Conclusions:

According to results obtained from a handbook of peer-reviewed data, Methanol is completely miscible in water at 20°C.

Reference 3

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

No data

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

not specified

GLP compliance:

yes

Type of method:

flask method

Water solubility:

49.2 g/L

Temp.:

20 °C

pH:

3.7

Details on results:

Preliminary solubility test
The estimated water solubility is approximately 8.29 g/L. This value means that the shake-flask method had to be applied. Because of the theoretical water solubility (47 g/L) the water solubility test was performed using the theoretical value.
The mean value of the water solubility of Test 1, 2 and 3 is 49.20 ± 0.35 g/L.

Solubility (shake flask method): Test number, stirring time, Tyndall value and the water solubility of the test substance at 20 ºC:

Test number	Stirring time (h)	pH	Tyndall	Water solubility (g/L)
1	24	3.75	0.0020 (0.0018)	48.86
2	48	3.54	0.0031 (0.0020)	49.57
3	72	3.98	0.0022 (0.0021)	49.16

The value between parentheses is Tyndall value of the blank.

Conclusions:

Interpretation of results: very soluble (> 10000 mg/L)
The water solubility of the test substance was 49.20 ± 0.35 g/L at 20.0 ± 0.5 ºC.

Description of key information

TMBX is hydrolytically unstable and experimental derivation of water solubility is technically not possible. A value of 10e6 mg/L is calculated by EPIWIN based on the Log Kow predicted value of -5.67 (KOWWIN v1.68) however given the hydrolytic instability of the substance this cannot be considered reliable. TMBX hydrolyses to form methanol and boric acid, both of which are toxicologically significant species and the water solubilities for these breakdown products should be considered instead.

According to results obtained from a handbook of peer-reviewed data, Methanol is completely miscible in water at 20°C. The water solubility of Boric Acid was measured to be 49.20 ± 0.35 g/L at 20.0 ± 0.5 ºC.

Key value for chemical safety assessment

Water solubility:

49.2 g/L

at the temperature of:

20 °C