Reaction mass of Disodium dihydroxy[2-{[5-(hydroxy-kO)-3-methyl-1-(4-sulfophenyl)-1H-pyrazol-4-yl]diazenyl-kN1}benzoato(3-)-kO]chromate(2-) and Sodium hydroxy[2-{[5-(hydroxy-kO)-3-methyl-1-(4-sulfophenyl)-1H-pyrazol-4-yl]diazenyl-kN1}benzoato(3-)-kO]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

Justification for type of information:

None

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Principles of method if other than guideline:

None

GLP compliance:

no

Type of method:

flask method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

None

Analytical method:

photometric method

Key result

Type:

log Pow

Partition coefficient:

-4.75

Temp.:

20 °C

Remarks on result:

other: pH not available

Type:

Pow

Partition coefficient:

0

Temp.:

20 °C

Remarks on result:

other: pH not available

Details on results:

None

Individual Results

Preliminary Visual Estimation of the n-octanol solubility

1 mg of the test item were stirred with different amounts of n-octanol at room temperature and visually checked for any undissolved particles.

Table: Appearance of the test mixtures

Amount of test item in mg	Volume in ml	Total volume in ml	Stirring time	Appearance of mixture
1	10	10	60 min	undissolved
1	40	50	60 min	undissolved
1	50	100	60 min	undissolved

According to this preliminary test the solubility of the test item in n-octanol is below 10 mg/l (without correction of the purity).

Calculation of the partition coefficient log Pow from the preliminary tests

The partition coefficient P ow may be estimated from the saturation concentrations in n-octanol and water by the following equation:

P ow = cs octanol /cs water

s= saturation

With the data obtained from the experiments, (cs < 0.01 g/l) and in the preliminary test (water solubility: cs = 399.9 g/l) the partition coefficient was calculated as log POW < -4.6.

Due to the fact, that the estimated log Pow is below -2, 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

Table: Solubility of the test item –experiments A to D

Experiment	A	B	C	D (blank)
Amount of test item (mg)	1000	1000	1000	-
Stirring time at 30°C (h)	24	48	72	72
Measured concentration (mg/l)	6.7	7.4	7.3	-
n-octanol Solubility (mg/l)	6.7	7.4	7.3	-

Average: 7.1 mg/l

Table: Concentrations of the standards for recheck:

Standard	Measured concentration (μg/ml)	% Recovery
Standard 2 (c= 2.63 mg/ml)	2.6	98.9
Standard 3 (c= 5.25 mg/ml)	5.1	97.1
Standard 5 (c= 21.0 mg/ml)	21.0	100

Recovery range from 97.1 to 100.0 % indicated a sufficient accuracy of the analytical method.

Calculation of the partition coefficient log Pow from the individual solubilities

By means of the flask method, the saturation concentration of the test item in n-octanol was determined to: 0.0071 g/l.

By means of the flask method, the saturation concentration of the test item in water was determined to: 399.9 g/l

Based on the above findings, the partition coefficent n-octanol/water of the test item at 20 °C, from the individual solubilities in water and n-octanol, was determined to:

log Pow = - 4.75, Pow = 0.000018

Conclusions:

The n-octanol/water partition coefficient (log Pow) of the test item at 20 °C was determined to be -4.75..

Executive summary:

The n-octanol/water partition coefficient of the test item was evaluated in a study conducted according to the EU Method A.8, OECD Guideline 107 and OECD Guideline 117. Flask method was used for this purpose. Based on the findings of the study, the n-octanol/water partition coefficient (log Pow) of FAT 20041/D TE at 20 °C was determined to be -4.75 (Pow = 0.000018).

Description of key information

The n-octanol/water partition coefficient (log Pow) of FAT 20041/D TE at 20 °C was determined to be -4.75 (Pow = 0.000018).

Key value for chemical safety assessment

Log Kow (Log Pow):

-4.75

at the temperature of:

20 °C

Additional information

The n-octanol/water partition coefficient of FAT 20041/D TE was evaluated in a study conducted according to the EU Method A.8, OECD Guideline 107 and OECD Guideline 117. Flask method was used for this purpose. Based on the findings of the study, the n-octanol/water partition coefficient (log Pow) of FAT 20041/D TE at 20 °C was determined to be -4.75 (Pow = 0.000018).