2,2',6,6'-tetrabromo-4,4'-isopropylidenediphenol

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:

11 March 2002 to 26 August 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted according to international guidelines and GLPs by an experienced laboratory using a composite of 3 manufacturers commercial product as test article.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7860 (Water Solubility Generator Column Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

other: generator column method

Water solubility:

0.148 mg/L

Temp.:

25 °C

pH:

5

Water solubility:

1.26 mg/L

Temp.:

25 °C

pH:

7

Water solubility:

2.34 mg/L

Temp.:

25 °C

pH:

9

Details on results:

The temperature of the water bath remained constant at 25.0 ± 0.1 °C throughout the experiment.

The nominal flow rate of reagent water through the generator column was measured prior to the start of sample collection for each flow rate trial. At the pump setting of 1.0 mL/min. the flow rate was measured at ~1.0 mL/min. At the pump setting of 0.5 mL/min. the flow rate was measured at ~0.5 mL/min.

The results from the analyses of pH 5 eluate samples from the generator column areas follows. The measured concentration of TBBPA in the eluate samples collected at the first flow rate of 1.0 mL/minute ranged from 0.145 to 0.156 mg TBBPA/L. The measured concentration of TBBPA in the eluate samples collected at the second flow rate of 0.5 mL/minute ranged from 0.139 to 0.154 mg TBBPA/L.

The results from the analyses of pH 7 aqueous eluate samples from the generator column are as follows. The measured concentration of TBBPA in the aqueous eluate samples collected at the first flow rate of 1.0 mL/minute ranged from 1.26 to 1.28 mg TBBPA/L. The measured concentration of TBBPA in the eluate samples collected at the second flow rate of 0.5 mL/minute ranged from 1.25 to 1.26 mg TBBPA/L.

The results from the analyses of pH 9 eluate samples from the generator column are as follows. The measured concentration of TBBPA in the aqueous solute samples collected at the first flow rate of 1.0 mL/minute ranged from 2.33 to 2.49 mg TBBPA/L. The measured concentration of TBBPA in the aqueous solute samples collected at the second flow rate of 0.5 mL/minute ranged from 2.03 to 2.51 mg TBBPA/L.

The results from the analyses of non-buffered reagent water eluate samples from the generator column are as follows. The measured concentration of TBBPA in the aqueous solute samples collected at the first flow rate of 1.0 mL/minute ranged from 0.236 to 0.243 mg TBBPA/L. The measured concentration of TBBPA in the aqueous solute samples collected at the second flow rate of 0.5 mL/minute ranged from 0.240 to 0.242 mg TBBPA/L. The pH of the aqueous solute measured before the column was 6.71. The pH of the aqueous solute measured post generator column at the beginning and end of each flow rate determination was 6.83, 6.79, 7.23, and 7.12, respectively.

The mean aqueous TBBPA saturation concentrations for the pH 5.0 generator column samples collected at 1.0 and 0.5 mL/minute flow rates were determined to be 0.149 ± 0.0039 mg TBBPA/L and 0.146 ± 0.0057 mg TBBPA/L, respectively. The overall mean water solubility at pH 5.0 and 25.0

0.1 °C was calculated to be 0.148 mg TBBPA/L. 

The mean aqueous TBBPA saturation concentrations for the pH 7.0 generator column samples collected at 1.0 and 0.5 mL/minute flow rates were determined to be 1.27 ± 0.0060 mg TBBPA/L and 1.26 ± 0.0055 mg TBBPA/L, respectively. The overall mean water solubility at pH 7.0 and 25.0 ± 0.1 °C was calculated to be 1.26 mg TBBPA/L. 

The mean aqueous TBBPA saturation concentrations for the pH 9.0 generator column samples collected at 1.0 and 0.5 mL/minute flow rates were determined to be 2.41 ± 0.0701 mg TBBPA/L and 2.27 ± 0.196 mg TBBPA/L, respectively. The overall mean water solubility at pH 9.0 and 25.0 ± 0.1 °C was calculated to be 2.34 mg TBBPA/L.

The mean aqueous TBBPA saturation concentration for the non-buffered reagent water generator column samples collected at 1.0 and 0.5 mL/minute flow rates were determined to be 0.239 ± 0.0024 mg TBBPA/L and 0.241 ± 0.0008 mg TBBPA/L, respectively. The overall mean water solubility using non-buffered NANOpure® reagent water at 25.0 ± 0.1 °C was calculated to be 0.240 mg TBBPA/L.

Conclusions:

Interpretation of results (migrated information): slightly soluble (0.1-100 mg/L) using non-buffered reagent water
The water solubility of TBBPA was determined in pH 5.0, pH 7.0, pH 9.0 buffer solutions, and in non-buffered NANOpure® reagent water at a test temperature of 25.0 ± 0.1°C using the generator column method. The water solubility in pH 5.0 buffer was 0.148 mg TBBPA/L. The water solubility in pH 7.0 buffer was 1.26 mg TBBPA/L. The water solubility in pH 9.0 buffer was determined to be 2.34 mg TBBPA/L. The water solubility in non-buffered reagent water was 0.240 mg TBBPA/L.

Executive summary:

In a guideline/GLP compliant study, the water solubility of TBBPA was determined in pH 5.0, pH 7.0, pH 9.0 buffer solutions, and in non-buffered NANOpure® reagent water at a test temperature of 25.0 ± 0.1°C using the generator column method. The water solubility in pH 5.0 buffer was 0.148 mg TBBPA/L. The water solubility in pH 7.0 buffer was 1.26 mg TBBPA/L. The water solubility in pH 9.0 buffer was determined to be 2.34 mg TBBPA/L. The water solubility in non-buffered reagent water was 0.240 mg TBBPA/L.

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

19 April 2000 to 4 May 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7840 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Water solubility:

<= 0.08 mg/L

Temp.:

21.5 °C

pH:

>= 7.6 - <= 8.1

Columns I and II and the blank column were eluted with water at a flow rate of 22-23 ml/hour and, on the same day, also at 10-12 ml/hour. Samples were taken at each flow rate and analysed. Because the analytical results for the samples from Columns I and II showed a slight decrease in concentration with time, additional samples were taken. Elution at 12 ml/h was therefore continued for Columns I and II till the next day. The next day, samples were taken from both columns at 23-24 ml/h, 10-12 ml/h and 5-6 ml/h. The temperature of the climate room was 21.5 ± 1.0°C during the performance of the test.

 

The HPLC chromatograms of the samples taken from the blank column did not show any peak with the same retention as the test substance.

 

The calculations were performed using not-rounded concentrations. Therefore, some differences might be observed when re-calculating the mean values, the maximum deviations and coefficients of variation.

 

The results show that the concentrations analysed in the eluate are flow dependent. The concentrations analysed were the highest for the samples taken at the high flow rate. This indicates that the flow dependency is not due to problems in reaching equilibrium. An explanation for the decrease in water solubility with decrease in flow rate cannot be given. Therefore, an upper value is reported for the water solubility of Tetrabromobisphenol A: ≤0.08 mg/l (i.e. ≤8*10^-5g/l).

Summary of the results of Column I and Column II

 

Flow [ml/hour]	Column	Mean concentration analysed [mg/l]
24 24 22 23	I I II II	0.082 0.066 0.081 0.070
12 12 10 10	I I II II	0.058 0.053 0.069 0.056
6 5	I II	0.046 0.048

Conclusions:

Interpretation of results (migrated information): insoluble (< 0.1 mg/L)
Using the column elution method, the water solubility of Tetrabromobisphenol A at 21.5 ± 0.5°C was determined to be <=0.08 mg/I (<= 8*10E-5 g/l)

Executive summary:

The water solubility of the test material was determined to be ≤0.08 mg/L at 21.5 ± 0.5 °C, according to Method A6 of EEC Directive 84/449 and OECD Guideline 105. This value is similar to that of MacGregor and Nixon (2002) in nonbuffered reagent water (e.g. 0.240 mg/L).

Reference 3

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

December 3, 2007 - April 30, 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted under international guidelines and GLPs by an experienced laboratory using commercial product as test article.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7860 (Water Solubility Generator Column Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Water solubility:

0.124 mg/L

Temp.:

25 °C

pH:

5

Water solubility:

1.1 mg/L

Temp.:

25 °C

pH:

7

Details on results:

For pH 5.0, the measured concentration of TBBPA in the eluate samples collected at the first flow rate of 1.0 mL/minute ranged from 0.123 to 0.137 mg TBBPA/L. The measured concentration of TBBPA in the eluate samples collected at the second flow rate of 0.5 mL/minute ranged from 0.103 to 0.126 mg TBBPA/L.

For pH 7.0, the measured concentration of TBBPA in the aqueous eluate samples collected at the first flow rate of 1.0 mL/minute ranged from 1.12 to 1.14 mg TBBPA/L. The measured concentration of TBBPA in the eluate samples collected at the second flow rate of 0.5 mL/minute ranged from 1.06 to 1.09 mg TBBPA/L.

Three pH 9.0 generator column trials were performed at a column flow rate of 1.00 mL/min and a fourth pH 9.0 generator column trial was performed at column flow rates of 1.00 mL/min and 0.500 mL/min. The first three columns did not equilibrate and eventually became mass depleted. A fourth column was set up and the concentration level of TBBPA that eluted from the column at 1.00 mL/min was much higher than expected, but gave consistent results. To confirm the solubility value, the same column was switched to a 0.500 mL/min flow rate and samples were collected. The results from the 0.500 mL/min flow rate were much higher (>30%) than the solubility results obtained from the 1.00 mLlmin and therefore failed the confirmation test. Results from the pH 9.0 generator column trials were not reported due to the absence of column-solute equilibrium at both 1.00 mL/min and 0.500 mL/min column flow rates.

The mean aqueous TBBPA saturation concentrations for the pH 5.0 generator column samples collected at 1.0 and 0.5 mL/minute flow rates were determined to be 0.129 ± 0.0055 mg TBBPA/L and 0.120 ± 0.0094 mg TBBPA/L, respectively, The overall mean water solubility at pH 5.0 and 25.0 ± 0.1 °C was calculated to be 0.124 + 0.0087 mg TBBPA/L.

The mean aqueous TBBPA saturation concentrations for the pH 7.0 generator column samples collected at 1.0 and 0.5 mL/minute flow rates were determined to be 1.13 ± 0.012 mg TBBPA/L and 1.07 ± 0.011 mg TBBPA/L, respectively. The overall mean water solubility at pH 7.0 and 25.0 + 0.1 °C was calculated to be 1.10 + 0.032 mg TBBPA/L.

The mean aqueous TBBPA saturation concentrations for the pH 9.0 generator column samples collected at 1.0 and 0.5 mL/minute flow rates were not determined due to the absence of column-solute equilibrium.

Conclusions:

Interpretation of results (migrated information): slightly soluble (0.1-100 mg/L)
The water solubility in pH 5.0 buffer was determined to be 0.124 ± 0.0087 mg TBBPA/L. The water solubility in pH 7.0 buffer was determined to be 1.10 ± 0.032 mg TBBPA/L. The water solubility of TBBPA in pH 9.0 buffer could not be determined due to the absence of column-solute equilibrium.
TBBPA can therefore be considered as slightly soluble.

Executive summary:

A water solubility study (471C-118) was performed on TBBPA using the column elution method. The study was conducted according to the OECD 105 and EPA OPPTS 830.7860 guidelines and was performed to GLP standard.

The water solubility in pH 5.0 buffer was determined to be 0.124 ± 0.0087 mg TBBPA/L. The water solubility in pH 7.0 buffer was determined to be 1.10 ± 0.032 mg TBBPA/L. The water solubility of TBBPA in pH 9.0 buffer could not be determined due to the absence of column-solute equilibrium. TBBPA can therefore be considered as slightly soluble. These results are consistent with those of MacGregor and Nixon 2002.

Reference 4

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

February - April 1978

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: The pH at which the water solubility measurements were made was not indicated.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Radiolabeled material was diluted to appropriate specific activity. Water was added to samples of the material and incubated overnight at 35°C then centrifuged. The remaining solution was radioassayed.

GLP compliance:

no

Type of method:

other: Radioassay

Water solubility:

0.72 mg/L

Temp.:

15 °C

Remarks on result:

other: The pH of the water used in this study was not reported.

Water solubility:

4.16 mg/L

Temp.:

25 °C

Remarks on result:

other: The pH of the water used in this study was not reported.

Water solubility:

1.77 mg/L

Temp.:

35 °C

Remarks on result:

other: The pH of the water used in this study was not reported.

Details on results:

Results are taken from an average of 2 readings.

Conclusions:

Interpretation of results (migrated information): slightly soluble (0.1-100 mg/L)
The water solubility values based on radioassays are as follows.
0.72 mg/L at 15 °C
4.16 mg/L at 25 °C
1.77 mg/L at 35 °C

Executive summary:

The water solubility of 14C-TBBPA was determined via radioassay at three temperatures. The solubilities determinded were 0.72 mg/L at 15 °C, 4.16 mg/L at 25 °C and 1.77 mg/L at 35 °C. The pH at which these measurements were made was not indicated.

Description of key information

Water solubility.001: Buffered water: pH 5: 0.148 mg/L; pH 7: 1.26 mg/L; pH 9: 2.34 mg/L at 25.0 ± 0.1 °C; Non-buffered water: 0.240 mg/L at 25.0 ± 0.1 °C.
Water solubility.002: pH 7.6-8.1: ≤0.08 mg/L at 21.5 ± 0.5 °C (non-buffered water).
Water solubility.003: 4.16 mg/L at 25 °C (pH not stated).
Water solubility.004: pH 5: 0.124 mg/L at 25 °C, pH 7: 1.10 mg/L at 25 °C.

Key value for chemical safety assessment

Water solubility:

1.26 mg/L

at the temperature of:

25 °C

Additional information

TBBPA is a weak acid that contains two ionizable hydroxy groups. Its water solubility is dependent on pH.  The ionized form of TBBPA is expected to be more water soluble than the non-ionized form. At acidic pHs, TBBPA is expected to be non-ionized and thus less soluble in water. At basic pHs, the opposite effect is expected.

In a GLP/Guideline-compliant study (Water solubility 001), TBBPA’s water solubility was determined in pH 5.0, 7.0 and pH 9.0 buffer solutions, and in non-buffered NANOpure reagent water at 25.0 ± 0.1 °C using the generator column method. In buffer, TBBPA’s water solubility was 0.148 mg/L (pH 5.0), 1.26 mg/L (pH 7.0), 2.34 mg/L (pH 9.0). In nonbuffered reagent water, TBBPA’s solubility was 0.240 mg/L. These results conform to expectations.