Rose, Rosa damascena, 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:

From 15 to 22 November 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)

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

Specific details on test material used for the study:

 

Key result

Surface tension:

ca. 47.04 mN/m

Temp.:

19.9 °C

Conc.:

402.41 mg/L

Remarks on result:

other:

Remarks:

Concentration of a 90% saturated solution prepared with 1g/L of test item slow-stirred at 150 rpm for 72 h, estimated by TOC analysis and non GLP elemental analysis

The concentration of the test item in the 90% saturated test solution was determined as 402.41 mg test item/L (based on analysis of dissolved organic carbon in the test solution).

Table 4.10.1: Observations

Test	Mass (g)	Surface tension, Mean ± SD (mN/m)	Temperature (°C)
Negative control	0.2981 -0.2984	72.75 ± 0.03	20.9
Test substance: First series	0.1905 -0.1950	47.04 ± 0.26	19.9
Test substance: Second series	0.2140 -0.2165	47.14 ± 0.32	20.3

The surface tension of the negative control was determined with 72.75 mN/m, therefore showing a difference of 0.21% from the stated literature value (surface tension of H₂O at 21.0 °C: 72.60 mN/m according to Vargaftik et al., “International Tables of the Surface Tension of Water”, J. Phys. Chem. Ref. Data 12, 817, 1983). The difference lies within the accepted range of 1% deviation from literature value.

Detailed findings of each step are provided in the study report. Values ranging from 46.23 mN/m to 47.57 mN/m were recorded showing no significant variations.

The values of the single determinations show no significant difference (0.21 % < 5% between mean values of the two measurement series)

Therefore, no significant dependence on time was observed and no additional measurement series was required.

Results of TOC analysis of the filtrated test solution 90%:

TOC analysis of the filtrated test solution was performed in triplicate using the carbon analyser TOC after monthly calibration ad quality control after every start.

Table 4.10.2 Results of TOC

Time	TOC value in mg/L (=DOC)	C content in %w/w*	Concentration of 90% test solution in mg of test item/L (estimated)
After 72h	317.74	78.96	402.41
After 144h	304.72	78.96	385.92
Difference of TOC values in %	- 4.1

*determined by elemental analysis, performed under non-GLP conditions

The difference between the concentration of the test item in the 90% saturated test solution after 72h and after 144 h is below < 15% (-4.1%). Therefore the plateau of the solubility was considered reached after 72 h.

Conclusions:

The surface tension of an aqueous solution of the test item (at 90% saturated concentration using a loading rate of 1g/L of test item) was determined between as 47.04 ± 0.26 mN/m at 19.9 °C.
According to EU A.5 criteria, as the result is below the threshold value of 60 mN/m, the substance is considered to have surface active potential under the experimental conditions.
However considering that the structure of the known constituents of the substance are not characteristic of true surfactants, that the dissolved part of the substance is not representative of the whole substance and especially that it is not the intended use of the substance (i.e. not a desired property), this conclusion should be taken with caution.

Executive summary:

The surface tension of an aqueous solution of test item was determined according to EU method A.5 and OECD 115 under GLP using the plate method.

Two saturated solutions were obtained from an aqueous solution prepared with 1 g/L of test item slow-stirred for 72 h and for 144h.The TOC analysis showing no significant difference between the measurements of the both solutions, the plateau of solubility was considered reached after 72 h.

The concentration of the test item in the 90 % saturated test solution was estimated to be 402.41 mg/L (based on analysis of dissolved organic carbonand non-GLP elemental analysis).

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

The surface tension of the test item in aqueous solution was determined as 47.04 ± 0.26 mN/m at 19.9 °C.

One measurement series was performed for verification (after 63minutes). No significant changes and thus no significant dependence on time were observed

Description of key information

The surface tension of an aqueous solution of the test item (using a 90% saturated aqueous solution, prepared with a loading rate of 1g/L of test item, slow-stirred at 150 rpm for 72 h. Concentration estimated by TOC analysis and non-GLP elemental analysis) was determined to be 47.04 mN/m at 19.9°C.

According to EU A5 criteria, as the result is below the threshold value of 60 mN/m, the substance is considered to have surface-active potential under the experimental conditions.

However, since the structures of the known constituents of the substance are not characteristic of true surfactants and considering that the dissolved part of the substance is not representative of the whole substance and especially that it is not an intended use of the substance (i.e. not a desired property), this conclusion should be taken with caution.

Key value for chemical safety assessment

Surface tension:

47.04

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

402.41

Additional information

A reliable experimental study, conducted according to a recognized OECD/EU method (plate method) and under GLP, is available.

It is considered as a key study.