Phosphoric acid, 2-ethylhexyl ester

Surface tension

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Testing was conducted between 19 May 2011 and 06 August 2011.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

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 the relevant results. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions.

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.5 (Surface Tension)

Version / remarks:

The determination was carried out using a White Electrical Institute Co. Ltd. torsion balance for surface and interfacial tension measurements and a procedure based on the ISO 304 ring method.

Deviations:

yes

Remarks:

The surface tension result was not corrected using the Harkins-Jordan correction table

Principles of method if other than guideline:

The procedure based on the ISO 304 ring method was designed to be compatible with that specified in Method A5 Surface Tension of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 115 of the OECD Guidelines for the Testing of Chemicals, 27 July 1995The 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

Surface tension:

44.4 mN/m

Temp.:

21.2 °C

Conc.:

1.01 g/L

Results

Calibration factor (f)

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

Table 8.2

Reading (mN/m)	Temperature (ºC)	Literature Value (mN/m)	Calibration Factor
72.5	21.2	72.53	1.000
73.0	21.2	72.53	0.994
72.5	21.2	72.53	1.000
72.0	21.2	72.53	1.007
72.0	21.2	72.53	1.007
72.5	21.2	72.53	1.000
72.0	21.2	72.53	1.007
72.0	21.2	72.53	1.007
Mean Calibration Factor = 1.003

Sample solution readings

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

Table 8.3

Time (mins)	Reading (mN/m)	Temperature (ºC)
87	43.5	21.2
100	43.0	21.2
115	44.0	21.2
128	44.5	21.2
142	44.5	21.2
154	44.5	21.2
170	44.0	21.2

Mean reading                :   44.3 mN/m (mean of the last 5 readings)
Surface tension             = reading x calibration factor
                                         = 44.3 x 1.003
                                         = 44.4 mN/m
Temperature                  :   21.2 ± 0.5ºC
pH of sample solution  :   2.9

Conclusions:

The surface tension of a 1.01 g/l solution of test item has been determined to be 44.4 mN/m at 21.2 ± 0.5°C. The test item is considered to be a surface-active item.

Executive summary:

Method

The determination was carried out using a White Electrical Institute Co. Ltd. torsion balance for surface and interfacial tension measurements and a procedure based on the ISO 304 ring method. With the exception of the following deviation, the experimental procedure used was designed to be compatible with that specified in Method A5 Surface Tension of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 115 of the OECD Guidelines for the Testing of Chemicals, 27 July 1995.

• 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.

Conclusion

The surface tension of a 1.01 g/l solution of test item has been determined to be 44.4 mN/m at 21.2 ± 0.5°C. The test item is considered to be a surface-active item.

Reference 2

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The surface tension of the test substance was determined according to OECD Guideline 115.

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

Deviations:

no

GLP compliance:

no

Type of method:

OECD harmonised ring method

Surface tension:

36.27 mN/m

Temp.:

20 °C

Conc.:

1 003 mg/L

Remarks on result:

other: Measurement 1

Surface tension:

36.17 mN/m

Temp.:

20 °C

Conc.:

1 003 mg/L

Remarks on result:

other: Measurement 2

Surface tension:

36.13 mN/m

Temp.:

20 °C

Conc.:

1 003 mg/L

Remarks on result:

other: Measurement 3

Surface tension:

36.09 mN/m

Temp.:

20 °C

Conc.:

1 003 mg/L

Remarks on result:

other: Measurement 4

Surface tension:

36.04 mN/m

Temp.:

20 °C

Conc.:

1 003 mg/L

Remarks on result:

other: Measurement 5

Surface tension:

36.03 mN/m

Temp.:

20 °C

Conc.:

1 003 mg/L

Remarks on result:

other: Measurement 6

An aqueous solution of the test item in de-ionized water with a concentration of 1003 mg/l was prepared. After stirring for circa three days and adapting to 20 °C the measurement of the surface tension with the test item was carried out at 20 ± 0.5°C (19.8 °C), as follows:

 

The solution to be measured is transferred to the measurement vessel, taking care to avoid foaming. The measurement vessel was placed on the table of the test apparatus. The measurement vessel was raised until the ring was immersed below the surface of the solution. The time from starting the measurement was recorded (see table 1). Subsequently, the table top was lowered gradually and evenly at a rate of 0.3 cm/min to detach the ring from the surface until the maximum force was reached. The force was read on the tensiometer. The measurements were repeated until a constant surface tension value in 6 measurements is reached.

Measurement	1	2	3	4	5	6
Time (s)	29	90	151	212	272	333
s(mN/m)	36.27	36.17	36.13	36.09	36.04	36.03

Mean value:   s= 36.1 mN/m (corrected byZuidema and Waters[1])

Due to the fact that the surface tension is lower than 60 mN/m, the test item has surface-active properties.

[1]Zuidema, H., Waters, C.W.,Ind. Eng.Chem. Analyt.13 (1941), S. 312

Conclusions:

The surface tension of the aqueous solution at 20 °C is 36.1 mN/m (OECD 115).

Executive summary:

The surface tension of the aqueous solution at 20 °C is 36.1 mN/m (OECD 115). Due to the fact that the surface tension is lower than 60 mN/m, the test item has surface-active properties.

Description of key information

Surface tension = 44.4 mN/m (21.2 ± 0.5°C); Butler & White (2011); EU Method A.5.
Surface tension = 36.1 mN/m (20°C); Dornhagen (2012); OECD 115

Key value for chemical safety assessment

Surface tension:

44.4

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

1 010

Additional information

The overall endpoint determination was carried out using a White Electrical Institute Co. Ltd. torsion balance for surface and interfacial tension measurements and a procedure based on the ISO 304 ring method. The experimental procedure used was designed to be compatible with that specified in Method A5 Surface Tension of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 115 of the OECD Guidelines for the Testing of Chemicals, 27 July 1995.

The surface tension of a 1.01 g/l solution of test item has been determined to be 44.4 mN/m at 21.2 ± 0.5°C. The test item is considered to be a surface-active item.