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Environmental fate & pathways

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The ready biodegradability of Reaction mass of disodium N,N'-[(2-hydroxy-5-nonylphen-1,3-ylene)bis(methylene)]bis[N-methylaminoacetate] and sodium N-[(2-hydroxy-5-nonylphenyl)methyl]-N-methylaminoacetate, was assessed under aerobic conditions at a GLP accredited laboratory according to the OECD Guideline 301B, “Ready biodegradability; CO2 evolution test” (Best, 2018).


In an initial experiment conducted using a test item concentration equivalent to 10 mg carbon/L, the toxicity control vessel, containing both the test item and reference substance (sodium benzoate), showed <25% biodegradation after 14 days, indicating that the test item had inhibitory effects on the microbial inoculum activity. The definitive test therefore exposed activated sludge micro-organisms with mineral medium to a reduced test item concentration equivalent to 5 mg carbon/L. Tests were conducted in sealed culture vessels in the dark at temperatures between 22-24°C for 28 days.


The reference substance attained 79% biodegradation after 14 days, with >60% degradation within a 10-day window, thereby confirming the suitability of the inoculum and test conditions. All other validity criteria specified by the OECD 301B Guideline were also met.


The test item attained 0% biodegradation (based on CO2 evolution) after 28 days and is therefore concluded to be not readily biodegradable.

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