3-octoxypropane-1,2-diol

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Remarks:

(critical micelle concentration)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21 October 2019 - 26 November 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

other: ISO 4311 'Anionic and non-ionic surface active agents — Determination of the critical micellization concentration — Method by measuring surface tension with a plate, stirrup or ring'

Version / remarks:

1979

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EC A.5 'Surface Tension'

Version / remarks:

2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: OECD 115 'Surface Tension of Aqueous Solutions'

Version / remarks:

1995

Deviations:

no

Principles of method if other than guideline:

The Critical Micelle Concentration (CMC) was determined by measuring the surface tension of test item solutions at different test item concentrations. For surface active substances which form micelles in solution, the surface tension decreases with increasing concentration until the CMC is reached. At concentrations above the CMC, the surface tension remains constant.

GLP compliance:

yes

Type of method:

other: Surface tension measurements using the OECD harmonized ring method.

Key result

Water solubility:

1 120 mg/L

Temp.:

20 °C

Remarks on result:

other: critical micelle concentration

Table: Surface tension of substance solutions at different concentrations

Sample	Concentration C [mg/L]	Log C	Surface tension [mN/m]
1	10.028	1.0	69.78
2	100.28	2.0	51.59
3	1002.8	3.0	25.77
4	1547.1	3.2	24.43
5	1998.5	3.3	24.33
6	3004.0	3.5	24.32
7	3999.5	3.6	24.32
8	5014.0	3.7	24.30

(1) Five measurements were performed for each test concentration until equilibrium was reached (results for each measurement are in the study report).

Conclusions:

The critical micelle concentration of the substance was determined to be 1120 mg/L.

Executive summary:

The critical micelle concentration (CMC) of the substance was determined by measuring the surface tension of solutions at six different substance concentrations according to a method based on ISO 4311.

The surface tension measurements were performed according to the OECD harmonized ring method (according to EC A.5 and OECD 115). The measured surface tensions were plotted against the lograithms of the concentrations. Trendline y1 was obtained from the data of the test solutions with test item concentrations of 10.028, 100.28 and 1002.8 mg/L. Trendline y2 was obtained from the mean surface tension of the filtered test solutions at nominal test item concentrations of 1547.1, 1998.5, 3004.0, 3999.5 and 5014.0 mg/L. The log C at the intersection of both lines is regarded as the log CMC (critical micelle concentration) and was calculated to be 3.05. From this value the critical micelle concentration was calculated to be 1120 mg/L.

Description of key information

From a range finding study, the water solubility was estimated to be 1.3-1.5 g/L at 20°C and pH 7.8. This is only estimated value because the test substance is surface active. The critical micelle concentration (CMC) of the substance was determined by measuring the surface tension of solutions at six different substance concentrations according to a method based on ISO 4311. The surface tension measurements were performed according to the OECD harmonized ring method (according to EC A.5 and OECD 115). The critical micelle concentration was determined to be 1120 mg/L.

Key value for chemical safety assessment

Water solubility:

1 120 mg/L

at the temperature of:

20 °C