Sodium [3-hydroxy-4-[(1-hydroxy-5-sulpho-2-naphthyl)azo]naphthalene-1-sulphonato(4-)]chromate(1-)

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Principles of method if other than guideline:

None

GLP compliance:

no

Type of method:

shake-flask method to: flask method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

Identification: FAT 20290/C TE
Lot: TCC/02/2014/CR/002
Appearance: Blue powder

Analytical method:

other: UV- Perkin Elmer Lambda 25

Type:

log Pow

Partition coefficient:

-5.62

Temp.:

20 °C

Remarks on result:

other: pH is not specified

Details on results:

None

Preliminary Visual Estimation of the n-octanol solubility

In this step, 10 mg of test item did not dissolve in upto 50 ml of n-octanol, hence the solubility of the test item is considered to be below 200 mg/L.

Calculation of the partition coefficient log Pow from the preliminary tests

With the data obtained from the experiments in chapter 3.5.1 (cs < 200 mg/l) and in the preliminary test (water solubility: cs = 302 g/l) the partition coefficient was calculated as log POW < -3.2

Due to the fact, that the octanol solubility is below the LoQ, the partition coefficient n-octanol/water has to be estimated from the individual solubilities in water and n-octanol.

Determination of the solubility in the n-Octanol phase: Flask Methods

Based on the three experiments, solubility of the test item in n-octanol was found to be < 0.72 mg/L.

The recovery of 100.2 % indicated a sufficient accuracy of the analytical method.

Calculation of the partition coefficient log Pow from the individual solubilities

Using the saturation concentration of test item in n-octanol (<0.72 mg/L) and water (302 g/L), the partition coefficient was calculated to be <-5.62 (Pow: <2.38x10 ^-6).

Conclusions:

The n-octanol/water partition coefficient of FAT 20290/C at 20 °C, from the individual solubilities in water and n-octanol, was determined to be (log Pow) <-5.62.

Executive summary:

The n-octanol/water partition coefficient of the test item FAT 20290/C was determined in a study conducted according to the OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method), OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method) and EU Method A.8 (Partition Coefficient). Using the flask method, solubility of the test item in n-octanol was found to be < 0.72 mg/L. Based on this finding and using the solubility of test item in water (302 g/L), the n-octanol/water partition coefficient of the test item at 20 °C was determined to be:

Pow < 2.38 x 10^-6

Log Pow < - 5.62

Description of key information

The n-octanol/water partition coefficient of the test item FAT 20290/C was determined in a study conducted according to the OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method), OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method) and EU Method A.8 (Partition Coefficient). Using the flask method, solubility of the test item in n-octanol was found to be < 0.72 mg/L. Based on this finding and using the solubility of test item in water (302 g/L), the n-octanol/water partition coefficient of the test item at 20 °C was determined to be:

Pow = < 2.38 x 10^-6

Log Pow < - 5.62

In another supporting study, which was according to the OECD guideline 107, the n-octanol/water partition coefficient of FAT 20290/A was found to be -2.82 at 25 °C and pH 5.2.

Key value for chemical safety assessment

Log Kow (Log Pow):

-5.62

at the temperature of:

20 °C