2-[[4-[ethyl(2-hydroxyethyl)amino]phenyl]azo]-6-methoxy-3-methylbenzothiazolium methyl sulphate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

For justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Key result

Type:

log Pow

Partition coefficient:

-1.6

Temp.:

20 °C

Remarks on result:

other: pH not reported

Conclusions:

The partition coefficient (n-octanol/water) of the test item was estimated based on the ratio of the individual solubilities of the test item in water and n-octanol. The solubilities were determined according to the flask method.
It was found to be: log Pow = -1.6

Executive summary:

The partition coefficient (n-octanol/water) was determined using the flask method according to OECD 107. As the water solubility was determined to be 46 g/L in an other experiment, only the n-octanol solubility needed to be measured.

The quantity of test item necessary to saturate the desired volume of n-octanol is estimated from the preliminary test. About five times that quantity is weighed into each of three glass vessels fitted with glass stoppers. The batches are stirred for different times at 30 °C (24 h experiment, 48 h experiment, 72 h experiment) in tightly closed flasks.Another experiment is performed according to this procedure but without test item (“blank”). After equilibration (further stirring for 24 h at 20 °C) the suspensions are taken and prepared for the analytical determination via HPLC. The n-octanol solubility of the test item at 20 °C was determined to be 1.15 g/L (± 0.08 g/L). The water solubility of the test item at 20 °C was determined to be 46 g/L (± 3 g/L)in a seperate experimient.

The partition coefficient P_OWof the test item was determined to be: 0.025, wherefore the log P_OW was calculated to be -1.6.

This information is used in a read-across approach in the assessment of the target substance.

For justification of read-across please refer to the attached read-across report (see IUCLID section 13).

Description of key information

The partition coefficient (n-octanol/water) was determined using the flask method according to OECD 107. As the water solubility was determined to be 46 g/L in another experiment, only the n-octanol solubility needed to be measured.

The n-octanol solubility of the test item at 20 °C was determined to be 1.15 g/L (± 0.08 g/L). The water solubility of the test item at 20 °C was determined to be 46 g/L (± 3 g/L) in a separate experiment.

The partition coefficient P_OW of the test item was determined to be: 0.025, wherefore the log P_OW was calculated to be -1.6.

This information is used in a read-across approach in the assessment of the target substance.

For justification of read-across please refer to the attached read-across report (see IUCLID section 13).

Key value for chemical safety assessment

Log Kow (Log Pow):

-1.6

at the temperature of:

20 °C