Decanoic acid, mixed esters with heptanoic acid, isovaleric acid, octanoic acid and pentaerythritol

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02. Nov. 2017 to 13. Nov. 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

OECD Guidelines for the Testing of Chemicals, Method No. 105, adopted 27. Jul. 1995: “Water Solubility “

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

Commission Regulation (EU) No 260/2014 amending Regulation (EC) No 440/2008: Method A.6: “Water solubility, adopted 24 January 2014.

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Specific details on test material used for the study:

No further details specified in the study report.

Key result

Water solubility:

0.51 mg/L

Conc. based on:

test mat.

Temp.:

20 °C

Remarks on result:

other: pH not specified

Details on results:

Measurements during Equilibration
All solutions were measured in triplicate.
The carbon content in the test item 64.0 % was used in the calculation of the test item concentration from the measured DOC concentration. After the analysis of the sample of day 6, the plateau was considered as reached.
The measured value in the blank flask lay below the LOQ of TOC (< 0.1 mg/L) on days 3 and 6.

Measurements at Plateau
Due to a strong difference in the measured concentrations from the flasks 3 and 5 in comparison to the flasks 2, 4 and 6, the determination from the flasks 3 and 5 was repeated but nearly the same values were measured. Therefore, these values were not stated in the final report.

Results
The measurements from the flasks 1A – 1C, 2 – 4 and 6 were included in the calculation of the mean, as the value from the flaks 5 was stated as an outlier (Grubb’ test for outliers).
Mean at the plateau is 0.51 ± 0.13 mg/L.
No dependency of solubility on amount of the test item (nominal load) was perceived.

Equilibration

Day	Temperature [°C]	pH*	Measured Area	Mean Concentration DOC [mg/L]	Mean Concentration test item [mg/L]	Difference to previous sample [%]
1	20.0	5-6	422 506 446	0.25	0.40	-
2	20.0	5-6	484 503 491	0.28	0.44	+12.0
3	20.0	5-6	613 591 609	0.38	0.60	+34.6
4	19.5	5-6	577 558 599	0.36	0.56	-6.1
5	20.0	5-6	465 449 446	0.25	0.39	-30.6
6	20.0	5-6	469 453 464	0.26	0.40	+3.1

 

Plateau

Flask #	Temperature [°C]	pH*	Measured Area	Mean Concentration DOC [mg/L]	Mean Concentration test item [mg/L]
2	20.0	6.33	612 625 634	0.40	0.62
3	20.0	6.73	406 414 411	0.21	0.33
4	20.0	6.36	629 645 663	0.42	0.65
5	20.0	6.33	1096 1094 1112	0.82	1.28
6	20.0	6.38	653 698 662	0.44	0.69

 

Measurements used for Calculation of Solubility

Day	Flask	Concentration Test Item [mg/L]	Total Mean [mg/L]	Total Standard Deviation [mg/L] (RSD* [%])
1	1A	0.40	0.51	0.13 (25.6 %)
2	1B	0.44
3	1C	0.60
4	1A	0.56
5	1B	0.39
6	1C	0.40
6	2	0.62
6	3	0.33
6	4	0.65
6	5	1.28**
6	6	0.69

*RSD = relative standard deviation

**outlier

Conclusions:

The solubility of Hatcol 1570 in water was determined from the measured concentrations of DOC in the filtrated test solutions.
All replicates except the flask 5 showed good correspondence. The value from the flask 5 was stated as an outlier (Grubb’ test for outliers) and was not used in the calculation of the mean. The water solubility of the test item was stated as 0.51 ± 0.13 mg/L, correspond-ing to a relative standard deviation of 25.6 %. The measurement in a low range of DOC concentrations is a reason for a high RSD.
No observations arousing doubts concerning the accuracy of the results and the validity of the study were made.

Executive summary:

Title of Study: Determination of the solubility in water of Hatcol 1570 according to OECD 105 resp. EU A.6

 

Findings and Results:

The solubility of the test item Hatcol 1570 in water was determined by measurement of DOC concentration in the filtrated test solutions using TOC analyser.

 

In the pre-test, flasks with nominal concentrations 10 mg/L and 1000 mg/L were shaken at room temperature for 100 hours (approx. 4 days) and measured for DOC after membrane filtration (0.45 µm, PTFE). The measured DOC concentration was < 0.1 mg/L and 0.24 mg/L in the flasks with the nominal concentrations 10.0 mg/L and 1004 mg/L, respectively.

As dependency of the water solubility on the amount of the test item added was perceived, different loading rates were used in the main test. According to the guideline the slow-stirring flask method was used for the determination of the solubility of the test item in water.

 

In the main test, six different loading rates of the test item were chosen to study the effect of the loading rate on the measured water solubility: 1, 3, 5, 6, 8 and 10 g/L (nominal). Three flasks 1A - C with the same loading rate (5 g/L) were used during equilibration. Seven vessels (flasks blank, 1C (for the sampling point 72 h) and 2 – 6) were set onto the shaking apparatus (at 100 rpm) immediately. After 24 ± 2 hours, flask 1B (for the sampling point 48 h) and after 48 ± 2 hours, flask 1A (for the sampling point 24 h) were set on the shaker and all flasks were shaken for further 24 ± 2 hours at room temperature (20.0 ± 0.5 °C). Then, flasks 1A - 1C were taken from the shaker, samples were taken, membrane filtered and analysed for DOC via TOC analyser. Because of an upward tendency in the three values, the test was prolonged and the flasks 1A-C were measured on days 4 – 6. Due to a difference of less than 15 % in the concentrations on days 5 and 6 and no upward tendency, the test was finished on day 6. The final measurement was performed on day 6 as determination from flasks 2 – 6.

No Tyndall effect (i.e. a laser beam was not scattered when transmitted through the liquid) could be observed indicating that no colloidal dispersed particles or micells are present.

Dependency of solubility on amount of the test item (nominal load) was not perceived in the main test. The value from the flask 5 was stated as an outlier (Grubb’ test for outliers) and was not used in the calculation of the mean.

 

At the plateau, the concentration of Hatcol 1570 in water had reached:

0.51 ± 0.13 mg/L at 20.0 ± 0.5 °C

= 0.51 ± 0.13 * 10-3 kg/m3 (SI units)

(mean value ± standard deviation of five individual vessels)

 

As the DOC method measures the sum of all dissolved parts of the test item, this study doesn’t provide any insights on the stability of the test item in aqueous medium.

Description of key information

The water solubility of the test item was stated as 0.51 ± 0.13 mg/L

Key value for chemical safety assessment

Water solubility:

0.51 mg/L

at the temperature of:

20 °C

Additional information

The solubility of the test item Hatcol 1570 in water was determined by measurement of DOC concentration in the filtrated test solutions using TOC analyser.

In the pre-test, flasks with nominal concentrations 10 mg/L and 1000 mg/L were shaken at room temperature for 100 hours (approx. 4 days) and measured for DOC after membrane filtration (0.45 µm, PTFE). The measured DOC concentration was < 0.1 mg/L and 0.24 mg/L in the flasks with the nominal concentrations 10.0 mg/L and 1004 mg/L, respectively.

As dependency of the water solubility on the amount of the test item added was perceived, different loading rates were used in the main test. According to the guideline the slow-stirring flask method was used for the determination of the solubility of the test item in water.

 

In the main test, six different loading rates of the test item were chosen to study the effect of the loading rate on the measured water solubility: 1, 3, 5, 6, 8 and 10 g/L (nominal). Three flasks 1A - C with the same loading rate (5 g/L) were used during equilibration. Seven vessels (flasks blank, 1C (for the sampling point 72 h) and 2 – 6) were set onto the shaking apparatus (at 100 rpm) immediately. After 24 ± 2 hours, flask 1B (for the sampling point 48 h) and after 48 ± 2 hours, flask 1A (for the sampling point 24 h) were set on the shaker and all flasks were shaken for further 24 ± 2 hours at room temperature (20.0 ± 0.5 °C). Then, flasks 1A - 1C were taken from the shaker, samples were taken, membrane filtered and analysed for DOC via TOC analyser. Because of an upward tendency in the three values, the test was prolonged and the flasks 1A-C were measured on days 4 – 6. Due to a difference of less than 15 % in the concentrations on days 5 and 6 and no upward tendency, the test was finished on day 6. The final measurement was performed on day 6 as determination from flasks 2 – 6.

No Tyndall effect (i.e. a laser beam was not scattered when transmitted through the liquid) could be observed indicating that no colloidal dispersed particles or micells are present.

Dependency of solubility on amount of the test item (nominal load) was not perceived in the main test. The value from the flask 5 was stated as an outlier (Grubb’ test for outliers) and was not used in the calculation of the mean.

 

At the plateau, the concentration of Hatcol 1570 in water had reached:

0.51 ± 0.13 mg/L at 20.0 ± 0.5 °C

= 0.51 ± 0.13 * 10-3 kg/m3 (SI units)

(mean value ± standard deviation of five individual vessels)

 

As the DOC method measures the sum of all dissolved parts of the test item, this study doesn’t provide any insights on the stability of the test item in aqueous medium.