Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The distribution data generated using fugacity level III model of EPIWEB 4.1 indicates that C12-14 ADMAES is likely to partition mostly to soil (75.01%) and to a lesser extent to sediment (16.22%) and water (8.72%), with a negligible amount to air (0.0044%) (U.S. EPA, 2012c). However, considering its ready biodegradability, toxicokinetic data as well as the low BCF value (i.e., 69.22 L/kg ww), C12-14 ADMAES is not expected to persistent in the environment. The low vapour pressure (2.9 x10- 6 Pa at 25°C) together with low Henry’s law coefficient of 2.44 x 10- 8 Pa-m3/mole and the distribution data from the Level III fugacity modelling, further supports the expected low potential for C12-C14 ADMAES to distribute into the atmospheric compartment.

The experimentally determined Koc values of 282,624 and 2,658,608 (log Koc: 5.5 to 6.4) indicate that the read-across substance C12-16 ADBAC will adsorb to soil, does not easily desorb and can be considered immobile. Cationic surfactants adsorb to soil mainly due to ionic interaction with negatively charged surfaces. This means that there will be a poor correlation with organic carbon in soil and that sorption should not be normalized to the organic matter content in soil. Rather, the average Kd values should be used to estimate the solids-water partition coefficient in soil. When organic matter is not a determining factor in distribution in soil, sediment and suspended sediment, there is no difference in adsorption to these three compartments (based on dry weight) as the organic matter content is the only variable. This means that the solids-water partition coefficients in sediment and suspended sediment are both equal to 13,630 L/kg.