2,2-bis[[(1-oxoisononyl)oxy]methyl]-1,3-propanediyl diisononanoate

Endpoint summary

Additional information

The toxicity of 2,2-bis[[(1-oxoisononyl)oxy]methyl]-1,3-propanediyl diisononanoate (CAS 93803-89-5) to terrestrial organisms was tested in one available long-term toxicity test on earthworms. Eisenia fetida was exposed to the substance in artificial soil according the specifications given in OECD guideline 222 under GLP conditions (Eisner, 2013). Concentrations of 62.5, 125, 250, 500 and 1000 mg/kg dw were tested. The mortality and growth of adult earthworms was determined after 28 days. Another 28 days later the reproduction rate was assessedAdverse effects of the substance were not observed and thus a NOEC (56 d) ≥ 1000 mg/kg was determined based on reproduction. Studies on other terrestrial organisms are not available but a toxicity of the substance to terrestrial organisms is considered unlikely.

The test substance is characterized by a high log Koc (> 5) indicating a potential for adsorption to the soil particles. Tests with soil-dwelling organisms that feed on soil particles are therefore most relevant for the evaluation of soil toxicity 2,2-bis[[(1-oxoisononyl)oxy]methyl]-1,3-propanediyl diisononanoate. In the absence of a clear indication of selective toxicity, an invertebrate (earthworm or collembolan) test is preferred, as outlined in ECHA guidance section R.7.11.5.3 (ECHA, 2012). Chronic soil macroorganism data are available as mentioned above, no effects on reproduction for earthworms were observed (NOEC (56 d)≥1000 mg/kg soil dw). Moreover, 2,2-bis[[(1-oxoisononyl)oxy]methyl]-1,3-propanediyl diisononanoateshows no inhibition to aquatic microorganisms in the toxicity control of the biodegradation study resulting in a NOEC (14 d) of ≥ 29.1 mg/L. The applied test concentration is in the range of concentrations that can be expected in the influent of a sewage treatment plant, as the substance has low water solubility (< 0.05 mg/L). The ECHA Guidance Document R.7c (ECHA, 2012) states that a test on soil microbial activity will only be additionally necessary for a valid PNEC derivation if inhibition of sewage sludge microbial activity has occurred. Therefore, toxicity to soil microorganisms is considered to be unlikely.

In accordance with Regulation (EC) No. 1907/2006, Annex IX, column 2, 9.4 further studies on the effects on terrestrial organisms does not have to be conducted since the chemical safety assessment indicates that there is no need. The substance is characterised by a high log Koc (log Koc > 5) indicating a considerable potential for adsorption to the soil particles. Due to the low water solubility (< 0.05 mg/L), only low concentrations are expected in the pore water, which is the main exposure route for terrestrial plants. Therefore, tests with soil-dwelling organisms like earthworm which allows potential uptake via surface contact, soil particle ingestion and porewater (ECHA, 2012), are most relevant for the evaluation of soil toxicity. In addition, in the absence of a clear indication of selective toxicity, an invertebrate (earthworm or collembolan) test is preferred, as outlined in ECHA guidance section R.7.11.5.3, page 122. Thus, it can be assumed that earthworms would be highly exposed to toxicants in soil and hence are most sensitive to the potential adverse effects of the substance.

In accordance with Regulation (EC) No. 1907/2006, Annex IX, Column 2, 9.4 further studies on the effects on terrestrial organisms do not have to be conducted since the chemical safety assessment indicates that toxicity to other terrestrial organisms in comparison to soil macroorganisms is not expected to be of concern.