Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The photodegradation of Oleic-acid IQAC in air by reaction with OH radicals was calculated using EPIWIN v3.20, AOPWIN v1.92. Based on the reaction rate constant k(OH) =130 x 10E-12 cm³/molecule x sec (cis isomer) and k(OH) =137 x 10E-12 cm³/molecule x sec (trans isomer) and assuming a OH radical concentration of 5 x 10E5 radicals/cm³ half-lives of 2.96 and 2.79 h, respectively can be calculated.

The photodegradation of Oleic-acid based IQAC, DMS quaternised in air by reaction with ozone was also calculated using EPIWIN v3.20, AOPWIN v1.92. Based on the reaction rate constant k(O3) =13.0 x 10E-17 cm³/molecule x sec (cis isomer) and k(O3) =20.0 x 10E-17 cm³/molecule x sec (trans isomer) and assuming a ozone concentration of 7 x 10E11 molecules/cm³ half-lives of 2.116 and 1.375 h, respectively can be calculated.

These half-lives indicate that the substance entering the atmosphere will be very quickly photodegraded by reaction with ozone. Due to the very low vapour pressure and the very low Henry's Law Constant the substance under investigation will not be present in the gas phase in the atmosphere in appreciable amounts and therefore this elimination path will be only of minor importance.

Hydrolysis of Oleic-acid based IQAC, DMS quaternised proved to be rapidly at neutral to alkaline pH values within a few days (2.9 days at pH 7 and 1.2 days at pH 9). At low pH the half-lives of Oleic-acid based IQAC, DMS quaternised considerably longer (at pH 4: > 1 year at 25 °C). At pH 9 the half life was 1.2 days at 20 °C. With increasing temperature the hydrolysis rate increases to result in 27 hours 50 °C and 16 hours at 60 °C at pH 7, respectively.