N'-(1,3-dimethylbutylidene)-3-hydroxy-2-naphthohydrazide

Surface tension

Link to relevant study record(s)

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13 - 14 November 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Directive 92/69/EEC, A.5 (EEC publ no L383, Dec 1992)

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

Version / remarks:

(1995)

GLP compliance:

yes

Type of method:

OECD harmonised ring method

Key result

Surface tension:

67.9 mN/m

Temp.:

20 °C

Remarks on result:

other: test concentration: 90% of a saturated solution

According to the guideline criteria, substances showing a surface tension lower than 60 mN/m under the conditions of this method, should be regarded as being surface active materials.

The mean surface tension of water was determined as 70.7 mN/m. The surface tension of water at the test temperature cited in the literature is

σ_o= 72.58 mN/m (Krüss GmbH, at 20.1°C).

Determination of the calibration factor Φ_b:

Φ_b= σ_o/ σ_g= 72.58 / 70.7 = 1.027

The values of the individual measurements and the corrected surface tension of a solution of test substance in water at 90% saturation is shown in the table below. The time passed between preparation and the first measurement was 15 minutes.

Determination	Time expired^1 [min]	Surface tension^2[mN/m]
		measured	mean not corrected	mean corrected for calibration	mean correc- ted using Harkins & Jordan, 1930
1 2 3 4 5 6 7	15 16 18 19 20 21 22	64.2 65.1 66.2 66.5 66.3 66.4 66.3	66.3	68.1	67.9

¹     Time passed since the solution was transferred to the measurement vessel.

²     Because the surface tension of a test solution in the measurement vessel alters over a period of time, several measurements were performed until a state of equilibrium was reached. The mean value was calculated from measurement 3 - 7.

Conclusions:

Using the OECD harmonised ring method, the surface tension of a 90% saturated solution of BMH in water was determined as 67.9 mN/m. Based on the criteria as outlined in the guideline, it is concluded that BMH should not be regarded as a surface active material.

Description of key information

No surface activity (EC A.5, OECD 115: harmonised ring method)  

Key value for chemical safety assessment

Surface tension:

67.9

Additional information

Test concentration: 90% of saturation.