Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Fatty acids, soya, 2-ethylhexyl esters (CAS 93572-14-6) is considered to be readily biodegradable according to OECD criteria (76 – 90% (CO2 evolution) after 28 d (OECD 301B), read across). Due to the ready biodegradability a persitancy of the substance in the environment is not expected. Abiotic degradation by hydrolysis is not relevant for the substance as indicated by QSAR calculations resulting in estimated half-lives in water of 14.15 years at pH 7 and 1.41 years at pH 8. The substance is furthermore characterised by a low water solubility (WS >1 and <10 µg/L) and a low vapour pressure (<0.0001 Pa). Together with the estimated high log Koc of single substance components these characertistics indicate that the substance would mainly distribute to soil and sediment when released to the environment.

However, an exposure of these environmental compartments is unlikely, since the substance is expected to be extensively eliminated in conventional sewage treatment plants. In the case insoluble chemicals enter a standard Sewage Treatment Plant (STP), they will be extensively removed in the primary settling tank and fat trap and thus, only limited amounts will get in contact with activated sludge organisms, according to the Guidance on information requirements and chemical safety assessment, Chapter R.7b (ECHA, 2012). Due to the insolubility the substance is not expected to be present in the water column. The high adsorption potential of the substance (log Koc: 6.47 (MCI)) indicates a potential for adsorption to sewage sludge and thus a further decrease of the substance concentration in the water column is possible (Guidance on information requirements and chemical safety assessment, Chapter R.7b (ECHA, 2012). In conclusion, the concentration of the substance in conventional STP effluents is expected to be low.

The volatilization potential of the substance is negligible, based on a vapour pressure < 0.0001 Pa at 20°C. Nevertheless, if released into the atmosphere, the substance is expected to be rapidly photodegraded based on the estimated half-lives in air of2.51 hours to 4.51 hoursfor the main substance components (AOPWIN 1.92 program). Based on the above information, accumulation in air, subsequent transportation and deposition into other environmental compartments is not anticipated.

Due to the rapid environmental biodegradation and metabolization via enzymatic hydrolysis a relevant uptake and bioaccumulation in aquatic organisms is not expected. Enzymatic breakdown will initially lead to the free fatty acid and glycerol. These hydrolysis products will be metabolised and excreted in fish effectively (Tocher, 2003). The low bioaccumulation potential is also indicated by BCF/BAF values of 1116 L/kg and 160.9 respectively for the C18:1 FA component and BCF/BAF values of 1135 L/kg and 405.7 respectively for the C18:2 FA component (BCFBAF v3.01, Arnot-Gobas, including biotransformation, upper trophic).

A detailed reference list is provided in the technical dossier (see IUCLID, section 13) and within the CSR.