Quaternary ammonium compounds, C12-18-alkyltrimethyl, chlorides

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

key study

Study period:

2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

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 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Version / remarks:

Computational approach in OECD Guideline 107

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Version / remarks:

Computational approach in EU A.8

Deviations:

no

Principles of method if other than guideline:

Firstly, the water solubility of the test substance was determined based on CMC and the n-octanol solubility using refraction index for saturated solution of test substance. The partition coefficient was then calculated from ratio of the solubility of the test substance in octanol and water.

GLP compliance:

no

Type of method:

estimation method (solubility ratio)

Partition coefficient type:

octanol-water

Analytical method:

other: Computational approach

Key result

Type:

Pow

Partition coefficient:

ca. 179.05

Temp.:

20 °C

Remarks on result:

other: based on ratio of solubility in n-octanol and water/CMC

Key result

Type:

log Pow

Partition coefficient:

ca. 2.25

Temp.:

20 °C

Remarks on result:

other: based on ratio of solubility in n-octanol and water/CMC

Details on results:

-Solubility of the test substance in n-octanol: 188 g/L (ref: Holtin, 2020)
-Solubility of the test substance in water (based on CMC): 1.05 g/L(ref: Oosterwijk, 2020)

The log Pow was calculated according to the equation:
Pow = solubility of the test substance in n-octanol / solubility of the test substance in water
= 188,000 mg/L / 1050 mg/L
= 179.05 mg/L

Log Pow: 2.25

Conclusions:

Under the study conditions, the calculated partition coefficient (log Pow) of the test substance, based on solubility in n-octanol and water, was determined to be 2.25 at 20°C.

Executive summary:

A study was conducted to determine partition coefficient of the test substance, C12-18 TMAC (96.8% active), from the ratio of the solubility in n-octanol and water in accordance with guideline similar to OECD 107 and EU A.8. The water solubility of the test substance was determined to be 1.05 g/L based on critical micelle concentration (CMC) (Oosterwijk, 2020) and the n-octanol solubility was determined to be 188 g/L using refraction index for saturated solution of test substance (Holtin, 2020). Under the study conditions, the calculated partition coefficient (log Pow) of the test substance, based on solubility in n-octanol and water, was determined to be 2.25 at 20°C (KLK Kolb, 2020).

Reference 2

Endpoint:

partition coefficient

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

supporting study

Study period:

2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

Refer to the Quaternary ammonium salts (QAS) category or section 13 of IUCLID for details on the category justification.

Reason / purpose for cross-reference:

reference to other study

Reason / purpose for cross-reference:

reference to other study

Reason / purpose for cross-reference:

read-across source

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Version / remarks:

Computational approach in OECD Guideline 107

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Version / remarks:

Computational approach in EU A.8

Deviations:

no

Principles of method if other than guideline:

Firstly, the water solubility of the test substance was determined based on CMC and the n-octanol solubility using refraction index for saturated solution of test substance. The partition coefficient was then calculated from ratio of the solubility of the test substance in octanol and water.

GLP compliance:

no

Type of method:

estimation method (solubility ratio)

Partition coefficient type:

octanol-water

Analytical method:

other: Computational approach

Key result

Type:

Pow

Partition coefficient:

ca. 231.507

Temp.:

20 °C

Remarks on result:

other: based on ratio of solubility in n-octanol and water/CMC

Key result

Type:

log Pow

Partition coefficient:

ca. 2.37

Temp.:

20 °C

Remarks on result:

other: based on ratio of solubility in n-octanol and water/CMC

Details on results:

-Solubility of the test substance in n-octanol: 169 g/L (ref: Holtin, 2020)
-Solubility of the test substance in water (based on CMC): 0.73 g/L(ref: Mangnus, 2019)

The log Pow was calculated according to the equation:
Pow = solubility of the test substance in n-octanol / solubility of the test substance in water
= 169,000 mg/L / 730 mg/L
= 231.507 mg/L

Log Pow: 2.37

Conclusions:

Under the study conditions, the calculated partition coefficient (log Pow) of the test substance, based on solubility in n-octanol and water, was determined to be 2.37 at 20°C.

Executive summary:

A study was conducted to determine partition coefficient of the read across substance, C12-14 TMAC (97% active), from the ratio of the solubility in n-octanol and water in accordance with guideline similar to OECD 107 and EU A.8. The water solubility of the test substance was determined to be 0.73 g/L based on critical micelle concentration (CMC) (Mangnus, 2019) and the n-octanol solubility was determined to be 169 g/L using refraction index for saturated solution of test substance (Holtin, 2020). Under the study conditions, the calculated partition coefficient (log Pow) of the test substance, based on solubility in n-octanol and water, was determined to be 2.37 at 20°C (KLK Kolb, 2020).

Description of key information

The partition coefficient of the test substance was calculated using the ratio of individual solubilities in n-octanol and water (i.e., based on critical micelle concentration (CMC)), a method which is recommended for surface active substances according to OECD Guideline 107 (KLKL Kolb, 2020). 

Key value for chemical safety assessment

Log Kow (Log Pow):

2.25

at the temperature of:

20 °C

Additional information

(based on ratio of n-octanol solubility and critical micelle concentration)

The partition coefficient (log Kow) value of another test sample containing majorly C12 -14 chains was determined to 2.37 at 20 °C. The log Kow value of the more representative test sample has been considered for the risk assessment.