Oligomerisation products of 2,2'-[(1-methylethylidene)bis(4,1-phenyleneoxymethylene)]bisoxirane with acrylic acid and lauric acid

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

other: REACH Guidance Document “Guidance on information requirements and chemical safety assessment Chapter R.7a: Endpoint specific guidance”

Version / remarks:

2017

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

2014

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

1995

Deviations:

no

GLP compliance:

not specified

Type of method:

flask method

Key result

Water solubility:

>= 9.18 - <= 43.02 mg/L

Conc. based on:

other: Nominal concentration of test substance

Incubation duration:

1 h

Temp.:

20 °C

pH:

>= 5.8 - <= 5.99

Remarks on result:

other: No exact value for the solubility of the test substance in water can be stated.

Remarks:

corresponding to 9.2 - 4.3 % of the test substance relating to the nominal concentration of the test substance.

Details on results:

As the solubility was dependent on the nominal concentration, no exact value for the solubility of the test substance in water can be stated. The solubility range for the tested nominal concentration 100-1004 mg/L was 9.18 - 43.02 mg/L at 20.0°C, corresponding to 9.2 – 4.3 % of the test substance relating to the nominal concentration of the test substance. No observations arousing doubts concerning the accuracy of the results and the validity of the study were made.

Measurements during Equilibration:

All data which was acquired during equilibration time (flask 1A-C, days 1 – 4, 8 – 9) are presented in the following table:

 

Day	Temperature [°C]	pH*	Concentration DOC [mg/L]	Conc. Test Substance [mg/L]	Difference [%]
1	20.0	6	7.70	11.43
2	20.0	6	11.35	16.85	+47.4
3	20.0	6	11.89	17.66	+4.8
4	20.0	6	16.06	23.85	+35.1
8	20.0	6	15.05	22.35	-6.3
9	20.0	6	15.51	23.03	+3.1

*measurement via pH paper

The carbon content of the test substance 67.34 % was used in the calculation of the test substance concentration from the measured DOC concentration according to the following equation:

c_{Test substance} [mg/L] = c_DOC [mg/L] ∗ 100%/67.34%

 

The measured value in the blank solution was < 0.5 mg/L TOC. After the analysis of the sample of day 9, the plateau was considered as reached.

Measurements at Plateau:

The measured concentrations in the flasks 2 – 6 are presented in the following table:

 

Plateau:

Flask #	Temperature [°C]	pH*	Concentration DOC [mg/L]	Conc. Test substance [mg/L]
2	20.0	5.89	6.18	9.18
3	20.0	5.99	15.12	22.45
4	20.0	5.80	22.88	33.98
5	20.0	5.97	24.44	36.29
6	20.0	5.94	28.97	43.02

*measured via calibrated pH meter

 

The measurements from the flasks 2 – 6 were included in the calculation of the solubility of the test substance in water. The flasks 1A – 1C were used during the equilibration time only.

Measurements used for Calculation of Solubility:

 

Flask #	Measured Conc. Test Substance [mg/L]	Nominal Conc. Test Substance [mg/L]	Dissolved Part [%]
2	9.18	100	9.2
3	22.45	302	7.4
4	33.98	600	5.7
5	36.29	802	4.5
6	43.02	1004	4.3

 

Conclusions:

Under the study conditions, no exact value for the solubility of the test substance in water can be stated.

Executive summary:

The solubility of the test substance without diluting monomer in water was determined according to EU method A.6 and OECD TG 105 by measurement of DOC concentration in the filtrated test solutions using TOC analyser. Prior to this, the carbon content of the test substance was determined by elemental analysis, resulting in a value of 67.34 %. This value was used in the calculation of the test substance concentration from the measured DOC concentration.

In the preliminary test, the measured DOC concentration was 1.43 mg/L and 25.92 mg/L in the flasks with the nominal load 10.2 mg/L and 1001 mg/L, respectively. As dependency of the water solubility on the amount of the test substance added was observed, different loading rates were used in the main test. According to the guideline the flask method was used for the determination of the solubility of the test substance in water.

In the main test, six different loading rates of the test substance were chosen to study the effect of the loading rate on the measured water  solubility:  100,  302,  503,  600,  802  and  1004 mg/L. Three flasks (1A-1C) with the same loading rate (500 mg/L, nominal) were used during equilibration. Due to an upward tendency of the test substance concentration, the test was prolonged and the flasks 1A-1C were measured on days 4, 8 and 9. Due to a difference of less than 15 % in the concentrations on days 8 and 9 and no upward tendency in the last three values, the test was finished. All samples were kept at 20.0 ± 0.5°C for 1 hour before filtration.

The final measurement was performed on day 10 as determination from flasks 2-6. All double filtrated test solutions showed no Tyndall effect (i.e. a laser beam was not scattered when transmitted through the liquid).

As the solubility was dependent on the nominal concentration, no exact value for the solubility of the test substance in water can be stated. The solubility range for the tested nominal concentration 100-1004 mg/L was 9.18-43.02 mg/L at 20.0°C, corresponding to 9.2-4.3 % of the test substance relating to the nominal concentration of the test substance (Affolter, 2020).

Description of key information

The water solubility was determined according to OECD Guideline 105 and EU Method A.6 (Affolter, 2020).

Key value for chemical safety assessment

Water solubility:

43.02 mg/L

at the temperature of:

20 °C

Additional information

As the solubility was dependent on the nominal concentration, no exact value for the solubility of the test substance in water can be stated. The solubility range for nominal concentration of 100-1004 mg/L was 9.18-43.02 mg/L at 20.0°C, corresponding to 9.2-4.3% of the nominal concentration of the test substance.