COASOL 290 PLUS

Surface tension

Link to relevant study record(s)

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Deviations:

yes

Remarks:

The suface tension result was not corrected using the Hawkins-Jordan correction table as the correction is not applicable to the apparatus used.

GLP compliance:

yes (incl. QA statement)

Type of method:

ring method

Surface tension:

59 mN/m

Temp.:

21.7 °C

Conc.:

33 mg/L

Remarks on result:

other: This concentration represents about 90% of the solubility of the substance.

Description of key information

The surface tension of a 33 mg/l solution of the tested substance in water has been found to be 59 mN/m at 21.7 °C.

Key value for chemical safety assessment

Surface tension:

59

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

33

Additional information

Substances showing a solution surface tension of less than 60 mN/m are regarded as being surface-active by EC Method A5. However, a classic surfactant will have a value of approximately 40 mN/m or less. This test item gave a value of 58.9 to 59.0 mN/m. Although this is designated surface-active by EC Method A5, it was considered that this value was not low enough to solely designate the item surface-active, especially since the test item does not have a typical surfactant structure (polar head with carbon chain). Therefore, to provide further information, an assessment of the emulsification properties of the test item was carried out with the test item prepared in water saturated n-octanol and partitioned with an equal amount of n-octanol saturated water. Observations after this test showed that the two immiscible phases separated quickly and no emulsification was observed. It was, therefore, considered that although the test item gave a positive surface-active result in this test, the test item was not typically surface-active. Additionally, based on the above discussion and the results obtained in the partition coefficient test, it was considered that the partition coefficient test results were valid, even though it is generally considered that HPLC estimation may not be suitable for the partition coefficient test for surface-active items.

Conclusion: the surface tension of a 90 % saturated solution of test item in water has been determined to be 59.0 ± mN/m at 21.7 ± 0.5 °C. The test item was considered to be surface-active by definition of EC Method A5, but not significantly surface-active based on the chemical structure and emulsification potential in n-octanol and water.