Quaternary ammonium compounds, trimethylsoya alkyl, chlorides

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

key study

Study period:

February 02, 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Reason / purpose for cross-reference:

reference to other study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Version / remarks:

Calculated from individual solubilities in water and n-octanol, as the test substance is surface active

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.8 (Partition Coefficient - HPLC Method)

Version / remarks:

Calculated from individual solubilities in water and n-octanol, as the test substance is surface active

GLP compliance:

not specified

Type of method:

estimation method (solubility ratio)

Partition coefficient type:

octanol-water

Analytical method:

other: Not applicable

Key result

Type:

log Pow

Partition coefficient:

ca. 2.94

Temp.:

20 °C

Remarks on result:

other: Calculation method based on solubility ratio (log of n-octanol solubility/CMC)

Type:

log Pow

Partition coefficient:

ca. -0.266

Temp.:

20 °C

Remarks on result:

other: Calculation method based on solubility ratio (log of n-octanol solubility/water solubility)

Results

Log Pow based on water solubility conducted according to OECD 105:

The octanol solubility and water solubility were determined to 260 g/L and 480 mg/L respectively, in earlier studies.

Log Pow = Log Octanol solubility/Water solubility = log 260/480 = -0.266

The Log Pow for Soya TMAC was determined to be -0.266.

Considering that the substance is a surfactant, the CMC based water solubility equivalent is considered to be a more reliable value. Therefore, the octanol solubility and water solubility (based on CMC) were determined to 260 g/L and 300 mg/L respectively, in earlier studies.

Log Pow = Log Octanol solubility/Water solubility = log 260/0.3 = 2.938

The Log Pow for Soya TMAC was determined to be 2.94.

Conclusions:

Under study conditions, the partition coefficient of the test substance, TMAC S, was determined to be 2.94 at 20°C.

Executive summary:

The partition coefficient of the test substance, TMAC S, was calculated from individual solubilities in water and n-octanol, according to a method specified in OECD Guideline 107 and EU Mehod A.8. The partition coefficient was determined by dividing the octanol solubility by the water solubility. The logarithm of this value is called the Log Pow. It was assumed that there are no changes in volume when mixing water or octanol with the test substance. The octanol solubility and water solubility were determined to be 260 and 480 g/L in the respective studies. Based on these values the log Pow was calculated to be at -0.266. However, considering the substance is a surfactant, a CMC based water solubility equivalent, which is considered to be practically more reliable value, was additionally determined at 300 mg/L at 20°C (Andersson, 2018). The log Pow using the n-octanol and CMC based water solubility was calculated at 2.94 at 20°C. Therefore, given that TMAC S is a surfactant, the CMC based log Pow has been considered further for hazard/risk assessment.

Description of key information

The partition coefficient of the test substance was calculated from individual solubilities in water (as well as CMC) and n-octanol, according to a method specified in OECD Guideline 107 and EU Method A.8 (Andersson, 2018).

Key value for chemical safety assessment

Log Kow (Log Pow):

2.94

at the temperature of:

20 °C

Additional information

The log Pow calculated based on n-octanol solubility and CMC ratio was 2.94 at 20°C; the log Pow calculated based on n-octanol and water solubility ratio was: -0.266 at 20°C. Therefore, considering that the substance is a surfactant, the log Pow (based on n-octanol solubility and CMC ratio) has been taken forward for the hazard and exposure assessment.