Sucrose, glycerol and propane-1,2-diol, reaction products with C16-18(even numbered) fatty acids

Water solubility

Description of key information

Sucroglyceride C16-18 contains very soluble constituents accounting for ca. 29% of the UVCB substance (Glycerol, Sucrose) and slightly soluble constituents (the larger part being fatty acid and fatty acid monoglycerides). Due to this composition, a single value for water solubility cannot be given.

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 physico-chemical properties of the components it is rather difficult to measure a reliable water solubility of the substance. A calculation of a single value for water solubility 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 water solubility were performed, where no data were available. To evaluate the reliability of the calculations, these were conducted with EPI suite v4.00,WSKOW v1.42. The calculations were also performed for those components, for which data from databases were available to compare the calculated to the measured data and to be able to judge their reliability.

The values retrieved from SRC database were:

for Glycerol: 1.0E+06 mg/L (very soluble)

for Sucrose: 2.1E+06 mg/L (very soluble)

for Palmitic acid: 0.04 mg/L (insoluble)

for Stearic acid 0.597 mg/L (slightly soluble)

The values obtained by calculation based on log Kow (WSKOW v1.42) and based on fragments (v1.01 est) were:

Glycerol: 1.00E+06 mg/L and 1.00E+06 mg/L (very soluble)

Sucrose: 1.00E+06 mg/L and 1.00E+06 mg/L (very soluble)

Palmitic acid: 0.041 mg/L and 0.010 mg/L (insoluble)

Stearic acid:0.0035 mg/L and 0.0093 (insoluble)

monoglyceride C16: 0.13 mg/L and 1.27 (slightly soluble)

monoglyceride C18: 0.0033 mg/L and 0.12 (insoluble to slightly soluble)

As the calculated values for water solubility are in a similar range as the data obtained from SRC database, it can be assumed that the EPI suite calculations give a good prediction for the solubility of the monoglycerides.

Sucroglyceride C16 -18 contains very soluble constituents accounting for ca. 29% of the UVCB substance (Glycerol, Sucrose) and slightly soluble constituents (the larger part being fatty acid and monoglycerides). Due to this composition, a single value for water solubility cannot be given.

The highly soluble components Sucrose and Glycerol are included in Annex IV and V, respectively, of REACH regulation, indicating that sufficient information is known to be considered to cause minimum risk because of the intrinsic properties or registration is otherwise deemed inappropriate or unnecessary. Thus, Sucrose and Glycerol will require no further assessment.

The fatty acids (C16 and C18) are present in organisms and can therefore be considered to be of low concern.

The fatty acid glycerides as well as the sucrose fatty acid mono esters contained in Sucroglyceride C16-18 will be rapidly de-esterified to glycerol, sucrose and fatty acids, which will then be further degraded via glucose and fatty acid metabolism.

Water solubility plays a role for the assessment of long-term adverse effects in the aquatic environment. But asSucroglyceride C16-18 has proven to be readily biodegradable, long-term adverse effects in the aquatic environment are not expected.