Commiphora myrrha, 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:

24 November 2015 to 11 January 2016

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The study was conducted according to an internationally recognized method, and under GLP. Restrictions apply considerinig that no measure of concentration of substance in water was performed due to technical issue (complex nature of the substance). Test substance is adequately specified. Therefore validation with restrictions 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:

UK GLP compliance programme (inspected on 17 June 2015 / signed on 24 September 2015)

Type of method:

ring method

Key result

Surface tension:

>= 56.8 - <= 60.4 mN/m

Temp.:

21.2 °C

Remarks on result:

other: surface tension of duplicate 90 % saturated solutions obtained from the supernatant of solutions prepared at a loading rate of 1 g/L. Concentration and composition of the substance in water not measured.

Table 4.10/1: Sample 1 and 2 – results

 

Time (mins)	Reading (mN/m)	Temperature (°C)
Sample 1
83	61.0	21.2
95	60.0	21.2
106	60.5	21.2
116	60.5	21.2
130	60.5	21.2
140	60.5	21.2
Sample 2
146	55.0	21.2
158	56.0	21.2
169	56.5	21.2
179	56.5	21.2
189	57.0	21.2
200	57.0	21.2
210	57.0	21.2

 

Mean Sample 1 result: 60.4 mN/m (n = 5 latest consecutive measurements)

Mean Sample 2 result: 56.8 mN/m (n = 5 latest consecutive measurements)

pH of Sample 1: 5.4

pH of Sample 2: 5.4

Overall result: 56.8 to 60.4 mN/m

Overall temperature: 21.2 ± 0.5 °C

Conclusions:

The surface tension of an aqueous solution of the test item (using a 90% saturated solution obtained with a loading rate of 1g/L of test item) was determined to be between 56.8 and 60.4 mN/m, at 21.2 ± 0.5 °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 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.

Executive summary:

The surface tension of an aqueous solution of the test item was determined under GLP according to OECD 115/EU A5 guidelines, using the ring method.

Two saturated solutions (sample 1 and 2) were obtained from the supernatant of aqueous solutions prepared at a loading rate of 1 g/L of test item, ultrasonicated, slow-stirred for 72h and equilibrated overnight at 20 +/-0.5°C and considered as saturated in the present preparation conditions. Then, six and seven readings were recorded from sample 1 and 2, respectively and the mean value was reported. Temperature and pH of sample 1 and 2 were recorded during the tests (Temperature = 21.2 ± 0.5 °C and pH = 5.4)

Mean Sample 1 result: 60.4 mN/m (n = 5 latest consecutive measurements)

Mean Sample 2 result: 56.8 mN/m (n = 5 latest consecutive measurements)

The results obtained on both replicates differ significantly (with a difference from the mean of greater than 1 mN/m).

Therefore, a range of surface tension between 56.8 and 60.4 mN/m at 21.2 ± 0.5 °C has been reported as the final result.

Description of key information

The surface tension of an aqueous solution of the test item (using a 90% saturated solution obtained with a loading rate of 1g/L of test item) was determined to be between 56.8 and 60.4 mN/m, at 21.2 ± 0.5 °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.

Additional information

A reliable GLP experimental study, conducted according to a recognized OECD/EU guideline, ring method, is available. Therefore, it is considered as a key study