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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

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Physical & Chemical properties

Partition coefficient

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Description of key information

 Weight of evidence is based on various studies performed according to relevant guidelines: due to the substance properties (strong bases, fully ionized at environmental pH; surface active compounds), according to EU method A.9, Pow was determined as the ratio of solubility in n-octanol (free amine) and water (hydrochloride of n-alkylamine). The highest resulting value from a homologous series of n-alkylamines is used for the category (worst case).

Key value for chemical safety assessment

Log Kow (Log Pow):
at the temperature of:
25 °C

Additional information

Sorption characteristics and the potential to form aggregates (surface active compounds) prevent a reliable measurement of the partition coefficient for primary fatty amines (PFA). PFA are difficult substances with regard to the determination of the partitioning coefficient n-octanol water (Pow): the compounds are strong bases (pKa 10.6), such that at neutral pH (pH 7) these compounds are ionised (primary ammonium ion) by 99.98%. The resulting primary ammonium derivative is surface active.

According to EU method A.9 (Partition Coefficient), neither of the two alternative methods outlined do fully apply:
The shake-flask method is not applicable to surface active materials: In conclusion, it could only be applied to a highly alkaline solution (pH 13 or higher), where less than 1% is present as primary ammonium ion and surface activity is thus minimal.
The HPLC method is neither applicable to surface active materials nor to strong bases. While ionisable compounds may be tested in buffered solutions, column properties do not allow for pH-values above 8, such that only the primary ammonium derivative can be tested, which is surface active.

According to EU method A.9, for such compounds Pow should be calculated from the solubilities in water and n-octanol. The present WOE approach follows this recommendation:

The relevant water solubility is the one of the alkyl ammonium derivative, i.e. the hydrochloride of the respective n-alkylamine.

Given the equilibrium in water between the alkyl ammonium ion and the free amine, relevant for octanol solubility is the one determined from the free amine (uncharged).


To choose a relevant worst-case key value for risk assessment, the following table presents available experimentally determined water solubilities (CMCs) of alkylamine hydrochlorides, together with experimental values for octanol solubilities of their respective free amine. Resulting calculated partition coefficients n-octanol/water are given in the table:


Table 1: Resulting partition coefficient n-octanol water (Pow) calculated from water solubilities (alkyl amine hydrochlorides) and n-octanol solublities (free amines):


Substance name

Solubility in octanol (20°C) [g/L]


Solubility in water (25°C) (CMC) [g/L]



log Pow



Clariant, 2009j


Clariant, 2008e





Clariant, 2009k


Clariant, 2009r





Clariant, 2009i


Clariant, 2010v





Clariant, 2009g


Clariant, 2010w





Clariant, 2009h


Clariant, 2009q




As could be expected, a clear increasing trend for Pow becomes obvious with increasing carbohydrate chain length.

The highest log Pow value (4.33) is resulting for(Z)-Octadec-9-enylamine, and this value is used as the worst-case key value for the whole category:


key value log Pow: 4.33 ((Z)-Octadec-9-enylamine)



Clariant (2008e): Dodecylamine Hydrochloride, Solubility in water, Critical micelle concentration, Report No.: 08-36296.1

Clariant (2009g): Octadecylamine, Solubility in n-Octanol, Report No.: 09-59852

Clariant (2009h): Oleylamine, Solubility in n-Octanol, Report No.: 09-59853

Clariant (2009i): Hexadecylamine, Solubility in n-Octanol, Report No.: 09-59854

Clariant (2009j): Dodecylamine, Solubility in n-Octanol, Report No.: 09-59855

Clariant (2009k): Tetradecylamine, Solubility in n-Octanol, Report No.: 09-59856

Clariant (2009q): Oleylamine Hydrochloride, Solubility in water, Critical micelle concentration, Report No.: 09-67123

Clariant (2009r): Tetradecylamine Hydrochloride, Solubility in water, Critical micelle concentration, Report No.: 09-63643-1

Clariant (2010v): Hexadecylamine hydrochloride, Solubility in water, Critical micelle concentration, Report No.: 09-67119

Clariant (2010w): Octadecylamine hydrochloride, Solubility in water, Critical micelle concentration, Report No.: 09-67120-1