C-C1

Surface tension

Administrative data

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Testing was conducted on 04 January 2008.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Version / remarks:

using a White Electrical Institute interfacial tension balance and a procedure based on the ISO 304 ring method.

Deviations:

yes

Remarks:

Please see "Principles of method if other than guideline"

Principles of method if other than guideline:

The surface tension result was not corrected using the Harkins-Jordan correction table as the correction is not applicable to the apparatus used. Once calibrated, the balance and ring assembly used in this test give a direct reading for surface tension that is within the required accuracy (± 0.5 mN/m); this is as a result of the reduced ring dimensions.

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of inspection: August 21st 2007 Date of signature: October 15th 2007

Type of method:

ring method

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

Sponsor's identification :C-C1
Description : dark blue powder
Lot number : MB-1
Purity : 96.3%
Date received : 05 March 2007
Storage conditions :room temperature, in the dark over silica gel

Results and discussion

Surface tension

Surface tension:

71.9 mN/m

Temp.:

22.4 °C

Conc.:

0.964 g/L

Any other information on results incl. tables

Sample solution readings

The readings, times and temperatures for the sample solution are shown in the following table:

Time (mins)	Reading (mN/m)	Temperature (ºC)
73	71.5	22.4
81	71.5	22.4
90	71.5	22.4
97	71.5	22.4
105	71.5	22.4
112	71.5	22.4

Mean reading                    :   71.5 mN/m
Surface tension                  = reading x calibration factor
                                         = 71.5 x 1.005
                                         = 71.9 mN/m
Temperature                      :   22.4 ± 0.2ºC
pH of sample solution        :   7.00

Applicant's summary and conclusion

Conclusions:

The test material is considered not to be a surface-active material.

Executive summary:

Method: The method employed complied with that specified in Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).

Discussion: The concentration of the main ingredient in the sample solution corrected for purity is lower than the required concentration of 1 g/l. The minor difference in sample concentration is not considered to have a significant effect on the reported surface tension result.

Substances showing a surface tension lower than 60 mN/m should be regarded as being surface‑active.

Conclusion: The surface tension of a 1.00 g/l solution (0.964 g/l corrected for purity) of test material has been determined to be 71.9 mN/m at 22.4 ± 0.2°C. The test material is considered not to be a surface-active material.