Acetic acid, oxo-, sodium salt, reaction products with ethylenediamine and phenol, iron sodium salts

Endpoint summary

Description of key information

The substance is neither acutely harmful nor harmful at chronic sub-lethal exposure to aquatic organisms.

Additional information

Fish:

The acute toxic effects of FeNaEDDHA to zebrafish were investigated in a study according to the principles of OECD guideline 203 and EU method C.1. The LC50 for a 96 hour exposure was > 120 mg/L for zebrafish.

Daphnia:

The acute toxic effects of FeNaEDDHA to Daphnia magna were investigated according to the principles of OECD-Guideline 202 and EU method C.2. The EC50 for a 48 hour exposure was greater than 120 mg/L based on the nominal concentration of the test substance and greater than 122 mg/L based on the mean measured concentrations.

In a long-term study, the structural analogue FeNa-EDDHMA had no effect on the survival of Daphnia magna at concentrations up to and including 1000 mg/L. A NOEC of 320 mg/L was derived based on reproduction and >=1000 mg/L based on parental mortality.

 

Algae:

The 72 hour EC50 value for FeEDDHA with the Desmodesmus subspicatus was > 293 mg/L and the NOEC was 8.1 mg/L based on mean measured concentrations and growth rate. The test substance inhibited algal growth in a concentration dependent manner, however, the test solutions were also colored by the test substance. The OECD 23 guidance document acknowledges that colored substances can absorb light and thus limit photosynthetic growth of algal cultures proportionally to test substance concentration. Consequently, the experimental system in this study was modified (i.e. increased light intensity, shortened light path, reduced inoculation density, and constant shaking) in order to compensate for the physical effect of color. These modifications are recommended in OECD 23, however the physical effect of color may not be completely eliminated. In addition, effects of complexing substances in algal growth inhibition tests are mainly caused by chelation of essential cations, which can lead to growth limiting reductions in the concentration of uncomplexed physiologically active ions under standard guideline conditions (Guidance on Hazard to the Aquatic Environment Globally Harmonized System GHS Annex 9 A9.3.3.4, 2007). Inhibition of algal growth by complexing agents is therefore a secondary effect, which cannot be attributed to substance specific inherent toxic properties. Mitigating modifications, such as by compensating the deficit in the concentration of the essential ion(s), were not applied. Therefore and since a suitable Lemna minor toxicity test performed according to OECD guideline 221 showed no effects throughout the exposure time of 7 days, the 72h-NOEC value of 8.1 mg/L was not further considered for the derivation of a PNEC for an environmental risk assessment.

Aquatic plants:

In a guideline study on the acute toxicity of FeNa-EDDHMA to Lemna minor the 7d-EC50 values for inhibition of log biomass growth (EbC50), specific growth rate (ErC50) and log biomass dry weight (EdwC50) were > 100 mg a.i./L and the NOEC >= 100 mg a.i./L.

 

Microorganisms:

The 3 hours EC10 value for the test substance FeNaEDDHA in the Activated Sludge Respiration Inhibition Test was 450 mg/L. The EC50 was greater than 1000 mg/L.