D-gluconic acid, compound with N,N''-bis(4-chlorophenyl)-3,12-diimino-2,4,11,13-tetraazatetradecanediamidine (2:1)

Surface tension

Link to relevant study record(s)

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020-04-16 to 2020-08-07

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:

yes (incl. QA statement)

Type of method:

OECD harmonised ring method

Key result

Surface tension:

63.87 mN/m

Temp.:

20 °C

Conc.:

1 g/L

Determination of the Density via Tensiometer for the Ring Method

The density of the test solution was determined in a preliminary measurement via buoyancy method to be 0.999 g/cm3 (20.1 °C). This density was used for the subsequently obtained surface tension values (correction method of HARKINS & JORDAN for the ring method, automatically taken into account by the tensiometer software).

 

Temperature

The temperature of the test solution during the whole series of measurements was in the range of 20.0 to 20.1 °C.

 

Time Line of the Determination of the Surface Tension

Start of measurement was 69.7 minutes after transfer of the test solution into the test vessel. After that time 63.1 minutes were needed to reach equilibrium at which 10 successive measurements were successfully achieved with a standard deviation of ≤ 0.05 mN/m.

 

Surface Tension of the Test Item

The determination was carried out in ten successive measurements with a standard deviation of ≤ 0.05 mN/m.

 

Surface Tension, Temperature

Measurement No.	Time 1) [min]	Time 2) [min]	Surface Tension [mN/m]	Temperature [°C]
75	126.0	56.3	63.94	20.1
76	126.7	57.1	63.94	20.1
77	127.5	57.8	63.92	20.1
78	128.2	58.6	63.89	20.1
79	129.0	59.3	63.87	20.1
80	129.8	60.1	63.83	20.1
81	130.5	60.9	63.84	20.1
82	131.3	61.6	63.83	20.1
83	132.0	62.3	63.82	20.1
84	132.7	63.1	63.81	20.1
Mean	-	-	63.87	20.1
SD [±]	-	-	0.05	0.00

 

SD = standard deviation

1) Time from transfer of test solution into test vessel until end of each measurement

2) Time from start of measurement until end of each measurement

 

Determination of the Reference Item

The surface tension of the reference item n-heptane was determined on 2019-06-13 as 20.22 ± 0.05 mN/m (20 °C) for the platinum iridium ring RI 21, internal no. 1, and is within the acceptable range of 20.23 ± 0.22 mN/m.

 

Validity Criteria

The temperature of the test solution has to be 20 ± 0.5 °C. The actual temperature was in the range of 20.0 to 20.1 °C.

Conclusions:

The surface tension of a 1 g/L aqueous solution of the test item Chlorhexidine Digluconate Solution (CHDG) was determined to be 63.87 mN/m (standard deviation ± 0.05 mN/m) at 20 °C. Considering that distilled water has a surface tension of 72.75 mN/m at 20 °C and the test item showed a surface tension above 60 mN/m under the conditions of this referring method, the test item should be regarded as being not surface-active material.

Description of key information

At a concentration of 1 g/L, a surface tension of 63.87 mN/m ws obtained at 20°C. 

Key value for chemical safety assessment

Surface tension:

63.87

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

1 000

Additional information

The surface tension of a 1 g/L aqueous solution of the test item Chlorhexidine Digluconate Solution (CHDG) was determined to be 63.87 mN/m (standard deviation ± 0.05 mN/m) at 20 °C. Considering that distilled water has a surface tension of 72.75 mN/m at 20 °C and the test item showed a surface tension above 60 mN/m under the conditions of this referring method, the test item should be regarded as being not surface-active material.