7-[(5-chloro-2,6-difluoro-4-pyrimidinyl)amino]-4-hydroxy-3-[(4-methoxy-2-sulphophenyl)azo]naphthalene-2-sulphonic acid, sodium salt

Surface tension

Link to relevant study record(s)

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May 02, 2018 to May 04, 2018

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)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Deviations:

no

GLP compliance:

no

Type of method:

ring method

Key result

Surface tension:

<= 57.3 mN/m

Temp.:

20.1 °C

Conc.:

900 mg/L

250.2 mg of the test item were put into 250 mL of de-ionized water (1000.8 mg/L) and stirred at ambient temperature. The test item was not completely solved after the stirring period. The test item was slighty turbid. Therefore the solution was filtered and diluted to 90 %. After adapting to 20 °C the measurement of the surface tension with the test item was carried out at 20 ±0.5°C (20.1 °C), as follows:

The solution to be measured was 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 Table1 below). 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 6 measurements were within the limits of the stability criterion.

Table1: Surface tension

Measurement	1	2	3	4	5	6
Time (s)	1242	1364	1485	1606	1727	1848
s(mN/m) uncorrected	62.73	62.67	62.58	62.54	62.52	62.44
s(mN/m) corrected according to Zuidema and Waters[1]	57.32	57.26	57.17	57.13	57.11	57.03

Due to the fact that the surface tension showed a time-dependence no mean value could be reported. However, the surface tension was lower than 60 mN/m, the test item had surface-active properties.

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

Executive summary:

The surface tension of the aqueous solution at 20 °C was lower than 60 mN/m. The test item had surface-active properties.

Description of key information

The surface tension of the aqueous solution at 20 °C was lower than 60 mN/m. The test item had surface-active properties.

Key value for chemical safety assessment

Surface tension:

57

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

900