Quaternary ammonium compounds, C18 and C18 (unsaturated) alkyltrimethyl, chlorides

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

November 10, 2016

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

other: AM46-2678

Version / remarks:

Krüss Standard Ring Method for surface tension measurements. CMC (water solubility) is achieved when surface tension has reached a plateau.

GLP compliance:

not specified

Type of method:

other: CMC method

Key result

Water solubility:

290 mg/L

Conc. based on:

test mat.

Loading of aqueous phase:

10 g/L

Remarks on result:

other: at room temperature

Remarks:

Incubation duration and pH: not specified

Conclusions:

Under the study conditions, the CMC based water solubility of the test substance was determined to be 290 mg/L at room temperature.

Executive summary:

A study was conducted to determine the water solubility (CMC) of the test substance according to AM46-2678. The instrument used was Krüss K100 force tensiometer and the method used was the Krüss Standard Ring for surface tension measurements. The measurement was performed in room temperature. The stock solution of product (10 g/L) was increasingly injected (30 injections) into clean water with a surface tension of 72 mN/m. Water solubility was achieved when surface tension had reached a plateau. CMC is an indication of water solubility for the product and indicates that the product is very soluble in water. Under the study conditions, the CMC based water solubility of the test substance was determined to be 290 mg/L at room temperature (Andersson, 2016).

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

December 01, 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

Preliminary testing

Deviations:

no

GLP compliance:

not specified

Type of method:

other: preliminary testing

Key result

Water solubility:

291 g/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

8

Remarks on result:

completely miscible

Results

At a weight ratio of 30:70 (substance:water) [%] a clear and homogeneous mixture is obtained. However, at a weight ratio of 35:65 [%] a clear and homogeneous mixture is not obtained, thus at this ratio the substance is not fully soluble in water. The pH of the solutions is close to 8 and the temperature is 20°C. The density of the substance is taken from Test facility Study No. 515667, “Determination of Physico-Chemical Properties of oleyltrimethylammonium chloride (dried)” and the value is 0.900 g/cm3 at 20 ºC. 0.2918 gram of the substance has a volume of 0.3242 cm3. 0.6782 gram MilliQ water has a volume of 0.6782 cm3. The total volume is thus 1.0024 cm3. The water solubility is the weight of the dissolved substance divided by the volume of the mixture.

Water solubility = Weight substance (0.2918 g) / Total volume (1.0024 cm3) = 0.2911 g/cm3 mixture.

The water solubility of ´test substance (solvent free)´ is determined to 291 g/L mixture.

Conclusions:

Under the study conditions, the water solubility of the solvent free form of the test substance was determined to be 291 g/L mixture.

Executive summary:

A study was conducted to determine the water solubility of the solvent free form of the test substance, Oleyl TMAC (91.9% active), using the preliminary test according to OECD Guideline 105. The substance was mixed with MilliQ water at different ratios in order to determine the water solubility, at pH 8 and 20 °C. It wasassumed that there are no changes in volume when mixing water and substance. Uptil a weight ratio of 30:70 (substance:water) [%], a clear and homogeneous mixture was obtained. However, at a ratio of 35:65 [%] a clear and homogeneous mixture was not obtained, thus at this ratio the substance is not fully soluble in water. Using the density value of of 0.9 g/cm3, water solubility was determined by dividing the weight of the dissolved substance with the totoal volume of the mixture. A weight of 0.2918 g of the test substance was determined to have a volume of 0.3242 cm3; and 0.6782 g MilliQ water had a volume of 0.6782 cm3. The total volume was calculated to be 1.0024 cm3. Under the study conditions, the water solubility of the test substance, was determined to be 291 g/L mixture (Linda, 2017).

Description of key information

The water solubility of the test substance was determined based on a preliminary test, according to OECD Guideline 105 Guideline (Wiman, 2016) as well as based on critical micelle concentration (CMC) value from the surface tension study, conducted according to AM46 -2678 (Krüss Standard Ring method) (Andersson, 2016).

Key value for chemical safety assessment

Water solubility:

290 mg/L

at the temperature of:

20 °C

Additional information

Water solubility (based on CMC): 290 mg/L at 20 °C (Andersson, 2016);

Water solubility (according to OECD 105):  291 g/L at 20°C and pH 8 (Wiman, 2017);

However, in line with the ECHA R.7a Guidance, the more reliable CMC based water solubility value for the test substance, which is a surfactant, has been taken forward for hazard/risk assessment.