Sophorolipids: fermentation products of glucose and rapeseed-oil fatty acids methyl esters with yeast Candida Bombicola

Surface tension

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Surface Tension Measurements should be performed on a solution at either 90 % of the solubility limit or 1 g/l (where viscosity permits), whichever is smaller. The test item, Sophorolipids (water solution), contained 58.4% dry matter, which is equivalent to a concentration of 584 g/L. Although this test solution was too concentration, the results are similar to the key study. Thus the study is considered reliable with acceptable restrictions and has been retained as a supporting study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

Deviations:

not specified

GLP compliance:

no

Type of method:

plate method

Surface tension:

>= 38.24 - <= 38.66 mN/m

Temp.:

20.1 °C

Conc.:

100 vol%

Remarks on result:

other: the tested item is the substance as produced (60% of dry substance in water)

Conclusions:

The surface tension of Sophorolipids is 38.45 mN/m +/- 0.21 mN/m.

Reference 2

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

GLP compliance:

yes (incl. QA statement)

Type of method:

ring method

Key result

Surface tension:

30.5 mN/m

Temp.:

20 °C

Conc.:

1 g/L

Conclusions:

The surface tension of a solution of Freeze dried Sopholiance in ultrapure water
(nominal 1.0 g/l) was determined according to the OECD Guideline No. 115, using the
ring method.
The result is:
30.5 mN/m
Therefore, according to this test, it was considered that the test material is surface active (surface tension < 60 mN/m).

Description of key information

Two studies for assessing the surface tension of a solution of the registered substance are available. Both were perfomred according to OECD Guideline 115. The results obtained were 38.45 mN/m (Processium 2012, plate method, reliability 2, non-GLP, supporting study) and 30.5 mN/m (Dutriez 2019, ring method, reliability 1, GLP, key study). The latter has been selected as the key value. According to both tests, the registered substance is considered is surface active (surface tension < 60 mN/m).

Key value for chemical safety assessment

Surface tension:

30.5

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

1 000

Additional information

Surface Tension Measurements should be performed on a solution at either 90 % of the solubility limit or 1 g/l (where viscosity permits), whichever is smaller. The test item in the Processium 2012 study report is described as Sophorolipids (water solution, contained 58.4% dry matter), which is equivalent to a concentration of 584 g/L. This concentration is too high but because the results are similar to the key study, which was performed at the required concentration of 1g/L, it has retained as a supporting study.