C-M5

Surface tension

Administrative data

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03 January 2008.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP and in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do no effect the quality of the 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)

Deviations:

yes

Remarks:

See principles of method

Principles of method if other than guideline:

With the exception of the following deviation, the experimental procedure used complied with that specified in Method A5 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).
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.
This deviation has been considered not to have affected the integrity of the study.

GLP compliance:

yes (incl. QA statement)

Type of method:

ring method

Test material

Reference

Name:

Unnamed

Type:

Constituent

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Results and discussion

Surface tension

Surface tension:

71.9 mN/m

Temp.:

21.8 °C

Conc.:

1.01 g/L

Any other information on results incl. tables

Results

Calibration factor (f)

The readings, temperatures and the corresponding calibration factors for glass double-distilled water are shown in the following table:

Reading (mN/m)	Temperature (ºC)	Literature Value (mN/m)	Calibration Factor
72.0	21.8	72.44	1.006
72.0	21.8	72.44	1.006
72.0	21.8	72.44	1.006
72.0	21.8	72.44	1.006
72.0	21.8	72.44	1.006
72.0	21.8	72.44	1.006
Mean Calibration Factor = 1.006

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)
65	71.0	21.8
75	71.5	21.8
86	71.5	21.8
95	71.5	21.8
103	71.5	21.8

Mean reading                     :    71.5 mN/m (mean of last 4 readings)
Surface tension                   =  reading x calibration factor
                                          =  71.5 x 1.006
                                          =  71.9 mN/m
Temperature                       :    21.8 ± 0.2ºC
pH of sample solution         :    7.05

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 1.01 g/l solution (0.937 g/l corrected for purity) of test material has been determined to be 71.9 mN/m at 21.8 ± 0.2°C.  The test material is considered not to be a surface-active material.

Applicant's summary and conclusion

Conclusions:

The surface tension of a 1.01 g/l solution (0.937 g/l corrected for purity) of test material has been determined to be 71.9 mN/m at 21.8 ± 0.2°C. The test material is considered not to be a surface-active material.

Executive summary:

The determination for substance C-M5 in project number 0345 -0980 was carried out using a White Electrical Institute interfacial tension balance  and a procedure based on the ISO 304 ring method.  With the exception of the following deviation, the experimental procedure used complied with that specified in Method A5 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).

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.

This deviation has been considered not to have affected the integrity of the study.

The surface tension of a 1.01 g/l solution (0.937 g/l corrected for purity) of test material has been determined to be 71.9 mN/m at 21.8 ± 0.2°C.  The test material is considered not to be a surface-active material.