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Potassium (Z)-N-methyl-N-(1-oxo-9-octadecenyl) aminoacetate (CAS 76622-74-7) is a salt, characterized by high water solubility (> 296 g/L) and low vapor pressure (< 0.0026 Pa at 20 °C), indicating that the substance is not volatile and that evaporation to air and subsequent transport through the atmosphere to other environmental compartments is not likely.

Since only limited data on the environmental fate of the substance are available, QSAR calculations were performed to estimate the log Koc and log Kow values of this substance.

Based on the calculated pKa of 3.96 (SPARC v4.6) and the log D profile (SPARC v4.6), the predominant species at environmental relevant pH values in the range of 4 to 9 is the ionized form (salt). The SPARC model predicts that at pH 5 less than 10% of the substance exists in the acid form and at pH 6 only about 1%.

The estimated log Koc (ChemProp v6.5,Franco, Fu, Trapp_Koc for ionizable substances) is 4.69 at pH 4, 2.63 at pH 7 and 2.30 at pH 9, suggesting a moderate potential for adsorption to particles present in soil and sediment in neutral to basic environments and a higher potential for adsorption in more acidic environments. Thus, a moderate accumulation and mobility in surface waters is expected at realistic pH values of around 7. The estimated log Kow of the salt is 3.10 (QSAR, KOWWIN v1.68), indicating a moderate lipophilicity and a moderate potential to accumulate in fat tissue.

Moreover, the substance is readily biodegradable based on the result of a standard biodegradation study (85.2% in 28 d; OECD 301B). Consequently, abiotic degradation via hydrolysis is not a relevant degradation pathway and bioavailability to aquatic organisms is presumably low because release into the environment is expected to be low due to ready biodegradability.According to the Guidance on information requirements and chemical safety assessment, Chapter R.7b, readily biodegradable substances can be expected to undergo rapid and ultimate degradation in most environments, including biological Sewage Treatment Plants (STPs) (ECHA, 2016).

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