Dimethyl azelate

Surface tension

Link to relevant study record(s)

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 1 to 14 December 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The study was conducted according to an internationally recognised method, and under GLP. The test substance is adequately characterised. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Version / remarks:

2008

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

inspected on 13 and 14 October 2014 / signed on 08 April 2015

Type of method:

plate method

Key result

Surface tension:

ca. 47.26 mN/m

Temp.:

19.6 °C

Conc.:

838.15 mg/L

Remarks on result:

other: The concentration of the test item in the 90% saturated test solution was determined to be 838.15 mg test item/L (based on analysis of dissolved organic carbon in the test solution).

Findings Main Test

The test item solution was held at constant temperature (20.0 ± 0.4 °C). 60 minutes after conclusion of the first measurement series, a second measurement series was performed for verification purposes.

The following values were recorded:

Table 4.10.1.-    Measured Values Test Item First Series

Measurement	Time	Mass	Surface Tension	Temperature
No	s	g	mN/m	°C
1	4.2	0.1951	47.59	19.6
2	5.1	0.1939	47.30	19.6
3	6.2	0.1938	47.28	19.6
4	7.1	0.1936	47.23	19.6
5	8.1	0.1935	47.20	19.6
6	9.1	0.1936	47.23	19.6
7	10.1	0.1938	47.28	19.6
8	11.1	0.1935	47.20	19.6
9	12.2	0.1931	47.11	19.6
10	13.2	0.1935	47.20	19.6
Mean			47.26
Standard Deviation			0.13

 

Table 4.10.2.- Measured Values Test Item Second Series

Measurement	Time	Mass	Surface Tension	Temperature
No	s	g	mN/m	°C
1	4.3	0.1962	47.86	19.7
2	5.3	0.1952	47.62	19.7
3	6.2	0.1952	47.62	19.7
4	7.3	0.1951	47.59	19.7
5	8.2	0.1948	47.52	19.7
6	9.3	0.1947	47.50	19.7
7	10.2	0.1962	47.86	19.7
8	11.3	0.1947	47.50	19.7
9	12.2	0.1953	47.64	19.7
10	13.3	0.1952	47.62	19.7
Mean			47.63
Standard Deviation			0.13

After the first and the second measurement series. the difference between mean values was less than 5%. Therefore no additional measurement series was required.

Analytical Determinations

The content of the test item in the test solutions was determined by calculation from carbon content of the test item and dissolved organic carbon (DOC) measurement.

The carbon content of 60.89 % was determined by elemental analysis, performed under non-GLP conditions at the accreditated laboratory Mikroanalytisches Labor Pascher, An der Pulvermühle 1, D-53424 Remagen, Germany.

The measured TOC value equates the dissolved organic carbon (DOC) of the filtrated test solution.

A value of 510.35 mg organic carbon/L was obtained and the concentration of the test item was calculated from the measured DOC and the stated carbon content.The calibration data is presented in the experimental report. The factors for the TOC of the daily measured quality control sample on 14. Dec. 2017 are:

IC=0.9890; TC = 1.0219.

The concentration was therefore determined as 838.15 mg test item/L.

Result Test Item

During the specified period of time. no significant changes in the surface tension were detected. Values ranging from 47.11 mN/m to 47.86 mN/m were recorded showing no significant variations. The values of the single determinations show no significant difference (less than 5 % between mean values of the two measurement series)

As the determined surface tension was lower than 60 mN/m. the test item can be classified as surface active.

Validity

Literature value for the surface tension of H₂O at 20.5 °C: 72.67 mN/m (taken from Vargaftik et al. “International Tables of the Surface Tension of Water”. J. Phys. Chem. Ref. Data 12. 817. 1983).

The surface tension of the negative control was determined with 72.93, therefore showing a difference of 0.36% from the stated literature value. The difference lies within the accepted range of 1% deviation from literature value.

Discussion

The values of the single determinations show no significant difference (0.78% between mean values of the two measurement series). All measured values lay clearly below the threshold for surface tension which is stated in the guidelines.

The surface tension of the negative control was determined with a difference of 0.36 % from the stated literature value.

Therefore the result of the test is considered valid and the test item is classified as “surface active” in a concentration of 838.15 mg/L (i.e. in a solution at 90% saturation obtained from an aqueous solution prepared with 1g/L of test item slow-stirring for 72h).

Conclusions:

The surface tension of an aqueous solution of the test item was determined as 47.26 ± 0.13 mN/m at 19.6 °C. As all measured values were lower than 60 mN/m, test item has potential for surface activity. As the result is below the threshold value of 60mN/m, the substance is considered to have surface active potential under the experimental conditions based on EUA.5 criteria.

Executive summary:

The surface tension of test item was determined according to EU method A.5 and OECD 115.

 

The concentration of the test item in the 90% saturated test solution was determined to be 838.15 mg test item/L (based on analysis of dissolved organic carbon in the test solution). The saturated solution was obtained from an aqueous solution prepared with 1 g/L of test item slow-stirred for 72h.

The surface tension of the negative control lay within the accepted range.

The surface tension of an aqueous solution of the test item was determined as 47.26 ± 0.13 mN/m at 19.6°C. One measurement series was performed for verification (after 60 minutes). No significant changes and thus no significant dependence on time were observed.
As all measured values were lower than 60 mN/m, the test item lwas classified as surface active.

Description of key information

Surface tension = 47.26 mN/m, at 90% saturation expected (838.15 mg/L)
As the result is below the threshold value of 60mN/m, the substance is considered to have surface active potential under the experimental conditions based on EUA5 criteria.

Key value for chemical safety assessment

Surface tension:

47.26

in mN/m at 20°C and concentration in mg/L:

838.15

Additional information

A fully reliable experimental study, conducted according to a recognized OECD/EU/ISO method and under GLP, is available. It is considered as a key study, and the result is retained as key value.