1-Propanaminium, 2-hydroxy-N-(2-hydroxypropyl)-N,N-dimethyl-, esters with C18-unsatd. fatty acids, Me sulfates (salts)

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:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
This read-across is based on the hypothesis that source and target substance have similar environmental fate properties based on similar physicochemical properties, common functional groups and structural similarities.
The target substance MDIPA-Esterquat C18 unsatd. is a UVCB substance consisting of diesters of mainly unsaturated C18 fatty acids with MDIPA as amine backbone.
The source substances DODMAC and DHTDMAC exhibit large structural similarities with the target substance. Details are described below.
Therefore, read-across from the existing bioaccumulation data on the source substance is considered as an appropriate adaptation to the standard information requirements of Annex IX, 9.3 of the REACH Regulation for the target substance, in accordance with the provisions of Annex XI, 1.5 of the REACH Regulation.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See justification for read-across attached to chapter 13 of this IUCLID file.

3. ANALOGUE APPROACH JUSTIFICATION
See justification for read-across attached to chapter 13 of this IUCLID file.

4. DATA MATRIX
See justification for read-across attached to chapter 13 of this IUCLID file.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across: supporting information

Key result

Type:

log Pow

Partition coefficient:

3.8

Remarks on result:

other: pH and temperature not reported

Description of key information

log Kow = 3.8; read-across from DODMAC (EU RAR 2009) 

Key value for chemical safety assessment

Log Kow (Log Pow):

3.8

at the temperature of:

20 °C

Additional information

Experimental data on log Kow qare not available for the target substance MDIPA Esterquat C18 unsatd. due to surface active properties of the substance. However, measured data from a structurally related substance are provided: the log Kow of DODMAC is reported to be 3.8. A justification for read-across is attached to iuclid section 13.

The n-octanol/water partition coefficients (log Kow) of the main constituents of MDIPA Esterquat C18 unsatd. were calculated to be in the range of 13.8 - 14.7 (Episuite v4.11, KOWWIN v1.68). However, charged molecules are outside of the applicability domain. Thus, the calculation is not reliable.

Calculated or measured Kow values are of limited practical use for cationic substances to estimate their physical properties or behaviour in the environment. An inherent property of cationic surfactants is that they accumulate at the interface between two phases. Thus, the accurate measurement of the Kow for any surfactant is difficult. Even if such measurements were made accurately, the Kow is not an appropriate hydrophobicity parameter for reliably predicting environmental behaviour because cationic substances in the environment instantaneously form complexes with naturally occurring negatively charged constituents in sewage, soils, sediments and with dissolved humic substances in surface waters.