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Ecotoxicological information

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In reliable acute studies on fresh water organisms (fish, algae, invertebrates and STP microorganisms) no toxicity was observed at high tested concentrations of 100 mg/L or higher (6-(isononanoylamino)hexanoic acid, compound with 2,2’,2’’-nitrilotriethanol). Only for the poorly soluble 6-(isononanoylamino)hexanoic acid testing high concentrations either as particulate suspensions (fish) or as solutions prepared using high concentrations of solubilizer (100 mg/L, microorganisms) adverse effects at high concentrations were observed. These are however regarded as not relevant due to most probably particle-induced physical toxicity (fish) or artificially high concentrations not expected to occur under conditions of STP or the environment (activated sludge respiration inhibition tests). In spite of these test conditions rendering the studies not or less reliable, observed toxicities were low (i.e. effect concentrations far above 100 mg/L).

Acute toxicity tests performed with 6-(isononanoylamino)hexanoic acid, compound with 2,2’,2’’-nitrilotriethanol on marine alga (Skeletonema costatum, not reliable) and a marine invertebrate (copepod Acartia tonsa, not reliable) might indicate higher toxicity to marine organisms. However, algal toxicity was moderate (EC10 72h, growth rate: 78.1 mg/L) and equivocal because in the pre-test no effects were observed up to 100 mg/L within 72 hours. While LC50-values (48 hours, immobility) between 5.86 and 10.5 mg/L are reported from the studies on Acartia tonsa, these are not reliable due to several impairments. Furthermore, in a reliable study on the marine fish species Scophthalmus maximus (Turbot) no toxicity up to the highest tested level of 6-(isononanoylamino)hexanoic acid, compound with 2,2’,2’’-nitrilotriethanol was observed (NOEC 96 hours: 1000 mg/L). This is in line with the results from the freshwater compartment.

Long-term studies are neither available nor deemed necessary for hazard assessment, as no toxicity in acute studies on freshwater organisms was observed and the compounds are readily biodegradable.