N, N-bis-(2-hydroxyethyl) dimethyl ammonium methane sulfonate

Surface tension

Link to relevant study record(s)

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study initiation date: 2021-02-02;
Experimental completion date: 2021-02-18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: DIN EN 14370 - Surface active agents - Determination of surface tension

Version / remarks:

2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Version / remarks:

European Commission Regulation (EC) No. 440/2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

Version / remarks:

1995

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

OECD harmonised ring method

Key result

Surface tension:

> 60 mN/m

Temp.:

20 °C

Conc.:

1.005 g/L

Remarks on result:

other: No surface-active properties

In the water solubility study (PS20200294-5), the test item was found to be completely miscible with water. Therefore, an aqueous solution of the test item in demineralized water with a concentration of 1005 mg/L was prepared and stirred at ambient temperature for 23 h. After adapting to 20 °C the measurement of the surface tension with the test item was carried out at 20 ± 0.5°C (20.5 °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 below and the Figure 1 given in the illustration attached to this endpoint study record). 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. After an equilibration time of the dissolved test item of about 20 min, 6 measurements were performed at an interval of approx. 2 min. As the surface tension of the test item showed a time-dependence the stability criterion of the test method could not be met. In a second measurement (data not shown) a tendency was observed, too. But since no tendency could be detected in the test measurement with water, it was assumed that this tendency was due to the physical-chemical properties of the dissolved test item.

Measurement	1	2	3	4	5	6
Time (s)	1238	1359	1479	1600	1721	1841
Time interval to the previous measurement (s)	--	121	120	121	121	120
s (mN/m)  uncorrected	68.81	68.73	68.63	68.56	68.47	68.40
s (mN/m)  corrected according to Zuidema and Waters [1]	63.32	63.23	63.14	63.06	62.98	62.91

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

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

Conclusions:

Surface tension (OECD 115; A.5) >60 mN/m at 20 °C

Executive summary:

The surface tension of the test item MAT-144 was determined in a reliable and valid study performed compliant with GLP according to OECD 115 (1995) as well as EU method A.5 using the ring-method.
An aqueous solution of the test item in demineralized water with a concentration of 1005 mg/L was prepared and stirred at ambient temperature for 23 h. After adapting to 20 °C, the measurement of the surface tension with the test item was carried out at 20 ± 0.5 °C (20.5 °C). Six measurements were performed at an interval of approx. 2 min. Because the surface tension of the test item showed a time-dependence (slightly decreasing from 63.32 mN/m to 62.91 mN/m over ca. 10 min) the stability criterion of the test method could not be met. In a second measurement, a tendency was observed, too. But since no tendency could be detected in the test measurement with water, it was assumed that this tendency was due to the physical-chemical properties of the dissolved test item.
Due to the fact that the surface tension showed a time-dependence, no mean value could be reported. However, as the surface tension was higher than 60 mN/m, the test item is concluded to have no surface-active properties.

Description of key information

Surface tension (OECD 115; A.5) >60 mN/m at 20 °C

Key value for chemical safety assessment

Surface tension:

62.91

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

1 005

Additional information

The surface tension of the test item MAT-144 was determined in a reliable and valid study performed compliant with GLP according to OECD 115 (1995) as well as EU method A.5 using the ring-method.
An aqueous solution of the test item in demineralized water with a concentration of 1005 mg/L was prepared and stirred at ambient temperature for 23 h. After adapting to 20 °C, the measurement of the surface tension with the test item was carried out at 20 ± 0.5 °C (20.5 °C). Six measurements were performed at an interval of approx. 2 min. Because the surface tension of the test item showed a time-dependence (slightly decreasing from 63.32 mN/m to 62.91 mN/m over ca. 10 min) the stability criterion of the test method could not be met. In a second measurement, a tendency was observed, too. But since no tendency could be detected in the test measurement with water, it was assumed that this tendency was due to the physical-chemical properties of the dissolved test item.
Due to the fact that the surface tension showed a time-dependence, no mean value could be reported. However, as the surface tension was higher than 60 mN/m, the test item is concluded to have no surface-active properties.

The last from the interval of six measured values (lowest value) is given as the key value because no relational operators can be used for key values.