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Partition coefficient

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Description of key information

The partition coefficient of the components of the test item have been estimated using specialist fragment constant methodology software, KOWWIN, version 1.67a (September 2008), © 2000 US Environmental Protection Agency.  The results ranged from Log Pow -2.48 to Log Pow 23.1.

Key value for chemical safety assessment

Additional information

The partition coefficient was estimated by fragment constant methodology using specialist chemical estimation software, KOWWIN, version 1.67a (September 2008), © 2000 US Environmental Protection Agency.

The accuracy of the software in its ability to assess the partition coefficient of a number of chemical classes was compared to available literature values. All software estimates were within one log unit and therefore the software was considered to be valid for the estimation of the individual components present in the test item. 

With respect to the environmentally relevant pH range for risk assessment of 5.0 to 8.0, there is potential for some ionisation of the mono- and di- and tri-substituted species, as the estimates of dissociation constants were in the range of 3.6 to 4.6. However, calculations have been performed on non-ionised forms only. 

The 2,2',2''-nitrilotriethanol(component D) was estimated to have a dissociation constant below 8.0 (pKa = 7.91). Therefore at pH 8.0 a proportion of the amine cation would donate its proton and revert to a non-ionised form. However, to present the highest partition coefficient, only that of the non-ionised form has been reported.

The partition coefficient of the components of the test item have been estimated using specialist fragment constant methodology software, KOWWIN, version 1.67a (September 2008),© 2000 US Environmental Protection Agency. The results are summarised in the following table:

Component Name

Partition Coefficient

Log10Pow

(9'Z,9''Z)nitrilotris(ethane-2,1-diyl) trioleate

1.15 x 1023

23.1

(Z)-((2-hydroxyethyl)azanediylbis(ethane-2,1-diyl) dioleate

2.59 x 1014

14.4

2-(bis(2-hydroxyethyl)amino)ethyl oleate

1.49 x 106

6.17

2,2',2''-nitrilotriethanol

3.34 x 10-3

-2.48