Zinc bis(2-ethylhexanoate)

Endpoint summary

Description of key information

In the assessment of environmental toxicity of zinc bis(2-ethylhexanoate), read-across to the assessment entities soluble zinc substances and 2-ethylhexanoic acid is applied since the ions of zinc bis(2-ethylhexanoate) determine its fate and toxicity in the environment. Reliable data available for soluble zinc substances and 2-ethylhexanoic acid indicate that the moiety of ecotoloxicological concern are zinc cations. Please refer to the respective assessment entities for more detailed information.

 

Acute (short-term) toxicity data:

The lowest EC/LC50 values of 3 trophic levels (algae, invertebrates and fish) for zinc range from 0.136 mg Zn/L to 0.78 mg Zn/L depending on the species tested and solution pH and hardness of the test medium.

The EC/LC50 values of 3 trophic levels (algae, invertebrates and fish) for 2-ethylhexanoate range from 49.3 mg 2Et/L to >100 mg 2Et/L.

 

Chronic (long-term) toxicity data:

For zinc, a species sensitivity distribution approach was applied with 23 distinct chronic species ecotoxicity values, and respective NOEC/EC10 values used for PNEC derivation range from 19 to 530 µg/L with a resulting HC5 of 20.6 µg Zn/L.

For 2-ethylhexanoic acid, the NOEC/EC10 values of 2 trophic levels (algae and invertebrates) range from 18 to 32 mg 2Et/L. According to the QSAR-based estimates of the model ECOSAR v.2.0, 2-ethylhexanoate has a very low potential for chronic toxicity to freshwater and saltwater fish with respective chronic values (ChV = 10^([log (LOEC x NOEC)]/2)) well above 15 mg/L.

 

Toxicity to aquatic microorganisms:

The lowest NOEC for nitrification inhibition by zinc amounts to 0.1 mg Zn/L based on an ISO 9509 nitrification inhibition test whereas a 17-h EC10 of 71.7 mg/L was identified for the inhibition of bacterial growth (Pseudomonas putida) by 2-ethylhexanoate.