7-Isopropyl-2H,4H-1,5-benzodioxepin-3-one

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 June 26 to July 08, 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was conducted according to a method recommended in international standards. No deviation was reported. The substance is considered to be adequately characterised with its purity. Therefore full validation applies.

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

Version / remarks:

27 July 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Version / remarks:

Regulation (EC) No 440/2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: ISO 304

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

UK GLP compliance programme (inspected on August 19, 2008 / signed on March 4, 2009)

Type of method:

ring method

Specific details on test material used for the study:

Storage conditions: approximately 4ºC in the dark under nitrogen.

Key result

Surface tension:

45 mN/m

Temp.:

21.6 °C

Conc.:

1.01 g/L

Table 4.10/1: Surface tension – results

Calibration with water:

Mean reading : 72.36 mN/m at 21.6°C (n=7)

Reference value (literature): 72.47 mN/m

Correction factor = 72.47/72.36 = 1.002

 

Test substance solution:

Time (mins)	Reading (mN/m)	Temperature (ºC)
90	44.5	21.6
100	45.0	21.6
110	45.0	21.6
120	45.0	21.6
130	45.0	21.6
155	45.0	21.6

 

Mean reading : 44.9 mN/m

Surface tension = reading x calibration factor = 44.9 x 1.002 = 45.0 mN/m

Temperature : 21.6 ± 0.5 °C

pH of sample solution : 5.34

Discussion

Substances having a surface tension below 60 mN/m are regarded as being surface-active. Therefore the value of 45.0 mN/m determined for the test material indicates that the test material is surface active. However, the test material 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 material was carried out with the sample solution used for the surface tension determination and partitioned with an equal amount of water saturated n-octanol. Observations showed that after the two immiscible phases separated, an emulsion was visible at the phase boundary. In addition, after the sample solution had been shaken vigorously, foam was observed to persist at the surface of the liquid.

Therefore the emulsification and persistent foam properties of the test material confirm the test material can be considered to be surface active.

Conclusions:

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.

Executive summary:

The surface tension of the test substance was measured under GLP according to OECD 115/EU A5 guidelines, ring method. Six readings were recorded, and the mean value was corrected with calibration factor from water.

The surface tension of the test substance is 45.0 mN/m, at 1.01 g/L and 21.6°C.

Surface-active properties were confirmed from visual assessment (emulsification, foaming) when mixing the test solution with octanol.

Description of key information

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. This was confirmed by visual assessment, however, the structure is not characteristic of a true surfactant, and it is not the intended use of the substance (i.e. not a desired property).

Key value for chemical safety assessment

Surface tension:

45

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

1 000

Additional information

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