Ferula galbaniflua, ext.

Surface tension

Link to relevant study record(s)

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January 15-18, 2016

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 substance is considered to be adequately characterised. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

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:

61.62 mN/m

Temp.:

19.7 °C

Conc.:

15.48 mg/L

Remarks on result:

other: The concentration of the test item in the 90% saturated test solution was determined to be 15.48 mg/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 ± 0.5 °C). 59 minutes after conclusion of the first measurement series, a second measurement series was performed for verification purposes.

Table 4.10/1: Measured Values Test Item First Series

Measurement No.	Time (s)	Mass (g)	Surface Tension (mN/m)	Temperature (°C)
1	2.9	0.2490	60.74	19.7
2	5.8	0.2529	61.69
3	8.9	0.2527	61.65
4	11.9	0.2531	61.74
5	14.9	0.2528	61.67
6	17.9	0.2529	61.69
7	20.9	0.2529	61.69
8	23.9	0.2536	61.86
9	26.9	0.2528	61.67
10	29.9	0.2531	61.74
Mean			61.62	-
SD			0.31	-

Table 4.10/2: Measured Values Test Item Second Series

Measurement No.	Time (s)	Mass (g)	Surface Tension (mN/m)	Temperature (°C)
1	2.9	0.2541	61.99	19.8
2	5.9	0.2579	62.91
3	8.9	0.2576	62.84
4	11.9	0.2576	62.84
5	14.9	0.2576	62.84
6	17.9	0.2573	62.77
7	20.9	0.2577	62.87
8	23.9	0.2574	62.79
9	26.9	0.2572	62.74
10	29.9	0.2574	62.79
Mean			62.74	-
SD			0.27	-

 

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

TOC analysis of the filtrated test solution was performed using the carbon analyser TOC multi N/C 2100S, Analytik Jena. The test solution was measured in triplicate. The carbon analyser was calibrated with freshly prepared reference solutions containing potassium hydrogen phthalate (TC), sodium hydrogen carbonate and sodium carbonate (IC) every month. After every start, quality control samples were measured.

A value of 13.39 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 carbon content in the test item had been determined under non-GLP-conditions in the laboratory Mikroanalytisches Labor Pascher (D-53424 Remagen) with 86.50 % w/w.

The concentration was therefore determined with 15.48 mg test item/L.

Result

During the specified period of time, no relevant changes in the surface tension were detected. Values ranging from 60.74 mN/m to 62.91 mN/m were recorded showing no relevant 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 of the test item was higher than 60 mN/m, the test item can be classified as not surface active.

Validity

Literature value for the surface tension of H₂O at 18.0 °C: 73.05 mN/m (Vargaftik et al., 1983).

The surface tension of the negative control was determined with 73.03 mN/m at 18.0 °C, therefore showing a difference of 0.03 % from the stated literature value. The difference lies within the accepted range of 1 % deviation from literature value.

The values of the single determinations show no relevant difference (1.82 % between mean values of the two measurement series). All measured values lay above the thresh-old for surface tension which is stated in the guidelines.

The surface tension of the negative control was determined with a difference of 0.03 % from the stated literature value.

Therefore, the result of the test is considered valid and the test item is classified as “not surface active” in a concentration of 15.48 mg/L (i.e. in a solution at 90% saturation obtained from an aqueous solution prepared with 1 g/L of test item slow-stirred for 72 h).

Conclusions:

The surface tension of an aqueous solution of the test item was determined as 61.62 ± 0.31 mN/m at 19.7 °C. As all measured values were higher than 60 mN/m, the test item is classified as not surface active.

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 15.48 mg/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 72 h.

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 61.62 ± 0.31 mN/m at 19.7 °C. One measurement series was performed for verification (after 59 minutes). No significant changes and thus no significant dependence on time were observed.

As all measured values were higher than 60 mN/m, the test item is classified as not surface active.

Description of key information

Surface tension = 61.62 mN/m, at 90% saturation expected (15.48 mg/L)
Since the measured result is above the threshold value of 60 mN/m, according to EU A5 criteria, the substance is NOT considered as surface-active under the experimental conditions

Key value for chemical safety assessment

Surface tension:

61.62

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

15.48

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.

The concentration of the test item in the 90 % saturated test solution was determined to be 15.48 mg/L (based on analysis of dissolved organic carbon in the test solution).