Registration Dossier

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The test substance Fatty acids, C16-18, esters with diethylene glycol (CAS 85116-97-8) is characterised by a low vapour pressure (<0.00001 Pa at 20 °C, SPARC (v4.6)), a low water solubility (< 1 µg/L at 20 °C, pH=6.3) and a log Koc indicating a potential for adsorption to soil and sediment particles (log Koc ≥ 3.27, MCI method, KOCWIN v2.01). Based on the result from a biodegradation study according to OECD 301B the substance is readily biodegradable (95% after 28 d).

Based on this result, Fatty acids, C16-18, esters with diethylene glycol will be significantly degraded in sewage treatment plants. In the case insoluble chemicals enter a standard Sewage Treatment Plant (STP), it 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. As a result of the potential for adsorption of the substance (log Koc ≥ 3.27, MCI method, KOCWIN v2.01) a removal from the water column to a significant degree by adsorption to sewage sludge can be expected (Guidance on information requirements and chemical safety assessment, Chapter R.7b, ECHA, 2016). In conclusion, the concentration of the substance in conventional STP effluents is presumably marginal. Due to ready biodegradability and based on the chemical structure, abiotic degradation via hydrolysis is considered as not relevant for the substance. Moreover, the substance is not volatile (vapour pressure < 0.00001 Pa at 20 °C) and thus evaporation to the air and subsequent transport through the atmosphere to other environmental compartments is not likely.

Based on the physico/chemical properties such as low water solubility and potential for adsorption a reduced availability in water is expected. Moreover, the substance is expected to be metabolised in aquatic organisms by breaking the ester bond and metabolisation of the enzymatic hydrolysis products (fatty acid and fatty alcohol). Diethylene glycol is expected to have a low potential for bioaccumulation based on the log Kow of -1.47. It can be concluded that the bioaccumulation potential of Fatty acids, C16-18, esters with diethylene glycol is negligible. In addition BCF/BAF values estimated by QSAR (BCFBAF v3.01) also support this assumption (BCF values all well below 2000 L/kg). Please refer to IUCLID Section 5.3 for a detailed overview on bioaccumulation of the substance.