Reaction products of diphosphorus pentaoxide and alcohol C7-9-iso, C8 rich, salted with 2-ethylhexylamine

Partition coefficient

Description of key information

logPow_OECD Guideline 123_Slow-Stir Method: 0.841 (cationic amine species), 0.280 (anionic mono-alkyl phosphate species), 4.28 (anionic di-alkyl phosphate species) 
OECD Guideline 107 and OECD Guideline 117: Study technically not feasible. (Fox, 2013)
Prediction with KOWWIN v1.68: logPow: 7.99 (Chemservice S.A., 2013)
Read-across substance_Phosphoric acid, mono- and di-(C8-C10) ester, compds. with C12 - 14 amine"_EU Method A.8_HPLC: logPow > 6.03; Pow > 1.08 x 10E6

Key value for chemical safety assessment

Log Kow (Log Pow):

4.28

at the temperature of:

25 °C

Additional information

The octanol-water partition coefficient of the target substance (Reaction products of diphosphorus pentaoxide and alcohol C7-9-iso, C8 rich, salted with 2-ethylhexylamine) was determined using the Slow-Stir Method according to OECD Guideline 123. Within specialized glass vessels, pre-saturated n-octanol and water two phase systems are maintained. The glass vessels are jacketed to allow temperature control of the solutions and are also designed to give access to both phases for sampling without disturbance of the opposite phase or phase boundary. The organic phase was sampled from the top by pipette and the aqueous phase by decanting from a tap at the base of the vessel. Initiation of sampling was done in Vessel 1 only, which acted as pilot test vessel in order to indicate the timepoint of equilibrium. This time point was evident from 357 h stirring. After this confirmation, sampling was performed also in all other test vessels. The concentration of the test substance in the sample solutions was determined by High Performance Liquid Chromatography - Mass Spectrometry (HPLC-MS), specifically for the cationic amine species ("Positive Component"), anionic mono-alkyl phosphate species ("Negative Component 1") and anionic di-alkyl phosphate species ("Negative Component 2"). In the structure of the target substance, Negative Component 1 and 2 are present at a ratio of approximately 1:1. The pH was kept neutral, as recommended for organic salts. As final results, the logPow values at 25 +/- 0.5 °C for the three representative structures of the test substance were reported as: 0.841 (Positive Component), 0.280 (Negative Component 1) and 4.28 (Negative Component 2), respectively. Since equilibrium was achieved for each of the three components in each of the three test vessels, the experimental results are considered as valid.

The method according to OECD Guideline 123 was applied since the "standard" methods (Shake flask method according to OECD Guideline 107 / HPLC method according to OECD Guideline 117) are not applicable for the compound.

For the complete structure of the target substance, a QSAR prediction was performed using the US-EPA EPIWIN software KOWWIN v1.68 (Chemservice S.A., 2013c). As overall result, the partition coefficient of the target substance was calculated to be 7.99. However, based on the complex structure, this information is regarded as not assignable.

The logPow of the read-across substance was determined to be > 6.03 according to EU Method A.8 (Lumsden, 1999).