Registration Dossier

Environmental fate & pathways

Phototransformation in air

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Stearic acid, esters with methyl α-D-glucoside is a mixture of all isomers of mono- to tetraesters and free carboxylates (acids) moeities. To get a hint on the physico-chemical data, a calculation was conducted for mono-, di-, tri- and tetraesters. The calculation yielded half-lives of 1.3 h, 1.1 h, 1.0 h and 0.9 h of mono-, di-, tri- and tetraesters respectively. These results indicate a very quick photodegradation of Stearic acid, esters with methyl α-D-glucoside in the atmosphere by reaction with OH radicals. For half-life in air the worst case (monoester) is used for safety assessment. The degradation rate constant with OH radicals for the monoester is 101.7E-12 cm³/molecule/s, but as the lowest value accepted by IUCLID for the degradation rate constant is 1E-09 cm³/molecule/s, the latter was used.

Key value for chemical safety assessment

Half-life in air:
1.3 h
Degradation rate constant with OH radicals:
0 cm³ molecule-1 s-1

Additional information

Stearic acid, esters with methyl α-D-glucoside is a mixture of all isomers of mono- to tetraesters and free carboxylates (acids) moeities. Because of the chemical complexity of the composition of the test substance, the calculation of physico-chemical properties for the mixture is not feasible. To get a hint on the physico-chemical data, a calculation was conducted for mono-, di-, tri- and tetraesters. The photodegradation in air by reaction with OH radicals was calculated using EpiWeb v.4.00, AOP Win v 1.92. Based on the reaction rate constants k(OH)= 101.7 x 10E-12 cm³/molecule x sec, k(OH)= 117.5 x 10E-12 cm³/molecule x sec, k(OH)= 133.1 x 10E-12 cm³/molecule x sec and k(OH)= 148.9 x 10E-12 cm³/molecule x sec mono-, di-, tri- and tetraesters respectively and assuming a tropospheric OH radical concentration of 1.5 x 10E06 radicals/cm³ half-lives of 1.3 h, 1.1 h, 1.0 h and 0.9 h of mono-, di-, tri- and tetraesters respectively, were calculated.

These results indicate a very quick photodegradation of the Stearic acid, esters with methyl α-D-glucoside in the atmosphere by reaction with OH radicals. Taking into account the very low vapour pressures and Henry's Law constants the derivates will not be present in the gas phase of the atmosphere in appreciable amounts and therefore this elimination path will only be of minor importance.