Registration Dossier

Diss Factsheets

Physical & Chemical properties

Partition coefficient

Currently viewing:

Administrative data

Link to relevant study record(s)

partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
according to guideline
other: ETAD method
Principles of method if other than guideline:
Estimation based on individual solubilities.
The analytical method for the determination is in agreement with the method that was agreed upon at the "Analytical Experts Meeting" ofETAD (Basel) on January 12, 2005.
GLP compliance:
Type of method:
estimation method (solubility ratio)
Partition coefficient type:
Analytical method:
voltammetric method
Key result
log Pow
Partition coefficient:
23 °C
Remarks on result:
other: pH value not available
Details on results:
The solubility of the sampie "Pigment Red 149" in water at ambient temperature, determined under the conditions as mentioned below, is 1.4 ~g per liter (0' = 0.6).
The solubility of the sampie "Pigment Red 149" in octanol at ambient temperature, determined under the conditions as mentioned below, is 1.9 ~g per liter (0' = 0.3).

Estimation of log Pow:

Pow= C(n-octanol) / C(water)= 1.9 µg/L / 1.4 µg/L = 1.35714

log Pow= 0.13

The partition coefficient of test substance was estimated to be log Pow= 0.13 at 23°C.

Description of key information

Estimated based on solubility ratio:

log Pow= 0.13 at 23°C

Key value for chemical safety assessment

Log Kow (Log Pow):
at the temperature of:
23 °C

Additional information

The partition coefficient was estimated based on the individual solubilities.

The determination of solubilities in water and in n-octanol was carried out by flask method according to OECD Guideline 105 and also by the ETAD method. This standard method was developed by intensive cooperation with the ETAD (Ecological and Toxicological Association of Dyesand Organic Pigments Manufacturers) and is regarded as acceptable for pigments.

The study based on ETAD method had been chosen as key study since the test substance was purified.