Registration Dossier

Diss Factsheets

Physical & Chemical properties

Partition coefficient

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Due to the complexity and the high variability in water solubility and dissociation constants of the components of the substance it is rather difficult to measure a reliable octanol/water partition coefficient. A calculation of a single partition coefficient for the UVCB substance is also not feasible. Thus, the main constituents of Sucroglyceride C16-18 were examined separately.   
Based on the recommendation given in the Guidance on Information Requirements (R7a), the octanol/water partition coefficients are given in ranges:
ca. 29% of the UVCB substance has a log Kow < 0
ca. 64% has a log Kow > 5

Key value for chemical safety assessment

Additional information

Sucroglyceride C16 -18 is a complex reaction product of partial esters of glycerol, propane-1,2-diol and sucrose with fatty acids and unreacted glycerol, fatty acids and sucrose. Due to this complexity and the high variability in water solubility and dissociation constants of the components it is rather difficult to measure a reliable octanol/water partition coefficient. A calculation of a single partition coefficient for the UVCB substance is also not feasible. Thus, the main constituents of Sucroglyceride C16-18 were examined separately. Where available, data from peer reviewed databases were taken. Calculations of log Kow were performed, where no data were available. To evaluate the reliability of the calculations, these were conducted with EPI suite v4.00, KOWWIN v1.68 and with SPARC on-line calculator v4.6. The mean was calculated from both results. The calculations were also performed for those constituents, for which data from databases were available to compare the calculated to the measured data and to be able to judge their reliability.

 

The octanol/water partition coefficients of Sucroglyceride C16-18 range from < 0 (Sucrose) to > 8 (Stearic acid).

 

Constituent

Calculated mean

Value from database

Glycerol

-2.09

-1.76

Sucrose

-5.96

-3.7

Palmitic acid

6.97

7.17

Stearic acid

7.47

8.23

Monoglyceride C16

5.83

not available

Monoglyceride C18

7.29

not available

 

Based on the relatively close calculated predictions of log Kow for the fatty acids compared to the values from the database, the results obtained for the fatty acid glycerides are considered reliable with restrictions.

 

Based on the recommendation given in the Guidance on Information Requirements (R7a), the octanol/water partition coefficients are given in ranges:

ca. 29% of the UVCB substance has a log Kow < 0

ca. 64% has a log Kow > 5