Lavender, Lavandula hybrida, 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 20 to 23 May 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

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:

51.85 mN/m

Temp.:

19.8 °C

Conc.:

326.18 mg/L

Remarks on result:

other: The concentration of the test item in the 90% saturated test solution was determined with 326.18 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	0.2982 -0.2988	72.82 ± 0.04	20.5
Test substance: First series	0.2099 -0.2133	51.85 ± 0.23	19.8
Test substance: Second series	0.2140 -0.2165	52.66 ± 0.17	19.9 -20.1

- Detailed findings of each step are provided in the study report.

- The test substance solution was held at constant temperature (20.0 ± 0.5 °C). 62 minutes after conclusion of the first measurement series, a second measurement series was performed for verification purposes.

- After conclusion of the first and the second measurement series, the difference between mean values was less than 5 %. Therefore, equilibrium was considered reached, no additional measurement series was required and the result of the first measurement series was stated.

- During a certain period of time, no relevant changes in the surface tension were detected. In dependence on time and temperature, values between 51.20 and 52.81 mN/m were recorded showing no significant variations (< 5 %). As the determined surface tension of test substance was lower than 60 mN/m, the test substance can be considered to have potential for surface activity.

 

Results of DOC analysis of the filtrated test solution:

- Measured DOC value (A): 247.67 mg of organic carbon/L

- Organic carbon content (B): 75.93%

- Concentration of the 90 % saturated test item = A / B = 326.18 mg of test item/L

Conclusions:

The surface tension of an aqueous solution of the test item (at 90% saturated concentration, measured at 326.18 mg of test item/L using a loading rate of 1g/L of test item) was determined as 51.85 ± 0.23 mN/m at 19.8 °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, since the structures of the constituents of the substance are not characteristic of true surfactants and that it is not an intended use of the substance (i.e. not a desired property), this conclusion should be taken with caution.

Executive summary:

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

A saturated solution was obtained from an aqueous solution prepared with 1 g/L of test item slow-stirred for 72 h.The concentration of the test item in the 90 % saturated test solution was determined to be 326.18 mg/L (based on analysis of dissolved organic carbon).

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 51.85 ± 0.23 mN/m at 19.8 °C.

One measurement series was performed for verification (after 62minutes). No significant changes and thus no significant dependence on time were observed.

Description of key information

Surface tension = 51.85 mN/m at 19.8°C on an aqueous solution at 90% saturated concentration using a loading rate of 1g/L of test item (concentration measured at 326.18mg of test item/L).
Since the measured result is below the threshold value of 60 mN/m, according to EU A5 criteria, the substance is considered to have surface-active potential under the exprimental conditions.

However, since the structures of the constituents of the substance are not characteristic of trus surfactant, this conclusion should be taken with caution.

Key value for chemical safety assessment

Surface tension:

51.85

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

326.18

Additional information

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