Tetrasodium 4-amino-5-hydroxy-6-[[2-methoxy-5-[[2-(sulphonatooxy)ethyl]sulphonyl]phenyl]azo]-3-[[4-[[2-(sulphonatooxy)ethyl]sulphonyl]phenyl]azo]naphthalene-2,7-disulphonate

Surface tension

Link to relevant study record(s)

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 30, 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

GLP compliance:

no

Other quality assurance:

ISO/IEC 17025 (General requirements for the competence of testing and calibration laboratories)

Type of method:

ring method

Key result

Surface tension:

66.9 mN/m

Temp.:

20 °C

Conc.:

1 g/L

Individual results

As the test item is highly soluble in water (see project 20150018.05) a concentration of about 1 g/L was used in the surface tension test. Therefore, an aqueous solution of the test item in de-ionized water with a concentration of 998.5 mg/Lwas prepared and treated with ultrasound for 15 min. After adapting to 20 °C for 1 hour the measurement of the surface tension with the test item was carried out at 20 ± 0.5°C (20.0 °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 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 6 measurements were within the limits of the stability criterion.

Table 1: Surface tension

Measurement	1	2	3	4	5	6
Time (s)	31	91	153	214	276	338
s(mN/m) uncorrected	72.47	72.37	72.36	72.38	72.39	72.43
s(mN/m) corrected by Zuidema and Waters[1]	66.96	66.86	66.85	66.87	66.88	66.91

 

Mean value:   s= 66.9 mN/m (corrected according to Zuidema and Waters^[1])

The test item had a mean surface tension of 66.9 mN/m. Due to the fact that the surface tension was higher than 60 mN/m, the test item had no surface-active properties.

 

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

Conclusions:

The surface tension of the substance was determined to be 66.9 mN/m with the OECD ring method.

Executive summary:

The surface tension of the aqueous solution of the test item at 20 °C was higher than 60 mN/m. The test item had no surface-active properties.

Description of key information

The surface tension of the test item according to the European Commission Regulation (EC) No. 440/2008, A.5. Surface tension of aqueous solutions and according to the OECD test guideline, OECD 115 (1995) Surface tension of aqueous solutions was determined to be 66.9 mN/m.

Key value for chemical safety assessment

Surface tension:

66.9

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

1 000

Additional information

The surface tension of the aqueous solution of the test item at 20 °C was higher than 60 mN/m. The test item had no surface-active properties.