Tetraammonium ethylenediaminetetraacetate

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

2.2 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

1.2 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.22 mg/L

Assessment factor:

100

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

43 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

0.72 mg/kg soil dw

Assessment factor:

100

Extrapolation method:

assessment factor

Additional information

EDTA is mainly produced and used as acid and sodium salt (Na4EDTA). In lower amounts, other salts or metal complexes are produced [EU Risk Assessment 2004].

Each category member has an identical backbone structure which is substituted with four carboxylic groups that result in a similar chemical reactivity. The available data indicate that all members of the category are likely to share comparable physicochemical and environmental properties.

For the hazard assessment several studies have been performed using EDTA acid, Na4 EDTA, Na2H2 EDTA or CaNa2EDTA. The several EDTA species have been used as read-across for the complete category, for justification please refer to IUCLID 5, chapter 13.

Aquatic compartment

The toxicity of EDTA on fish highly depends on water hardness, pH and metal speciation [EU Risk Assessment, 2004]. The toxicity of EDTA complexes to bluegill was determined in a key study performed by Batchelder et al. (1980), which take into account the water hardness and pH. The revealed LC50 -values are in a range of 41 mg/L to 2070 mg/L. Consequently and in line with EU risk Assessment (2004) [Tab 3.22] the LC50 of EDTA is estimated to be higher 1000 mg/L, due to the fact that this predicted value represents the lowest LC50 at acceptable pH which has been performed in natural not synthetic water. Tests on acute toxicity withDaphnia magnaresulted in EC50 value of 140 mg/L detected in a non-GLP study according to DIN 38412 with Na2EDTA [BASF AG, 1989]. The results of four studies on green algae indicates that the predicted LC50 for EDTA (acid form) and its salts are higher than measured 60 mg/L and can be estimated to be higher than 300 mg/L, which is in line with the EU Risk Assessment (2004).

The long-term toxicity of CaNa2EDTA on fish was measured in an early life stage study withBrachydanio rerio[BASF AG, 2001]. The study conducted according to OECD Guideline 210 and in compliance with GLP regulations revealed a 35 day NOEC of >= 25.7 mg/L.Further on, the long-term toxicity of Na2EDTA onDaphnia magnawas measured in an reproduction test according to GLP criteria[BASF AG, 1998]. After 21 days of exposure a NOEC of 25 mg/L was observed.In addition data of the toxicity of EDTA (acid form) on the duckweedLemna minorare available. As the test substance is a complexing agent which can dispose micronutrients from the culture medium, duckweed growth can be significantly reduced under standardized guideline conditions and may yield apparent results that are more or less severe than the true toxicity (see Guidance on Hazard to the Aquatic Environment Globally Harmonized System GHS Annex 9 A9.3.3.4, 2007). This was indicated by the results of the key study. Data revealed that growth were dependent on the concentration of EDTA and pH.

 

The toxicity of Na2EDTA on microorganisms was tested in an activated sludge respiration inhibition test according to OECD guideline 209 [Van Ginkel & Stroo, 2000]. The EC20 value after 30 min was measured to be > 500 mg/L. For Na4EDTA a similar low toxicity on activated sludge was measured in an respiration inhibition test according to ISO 8192 [BASF AG, 1988]. In this test a concentration of 1000 mg/L test substance caused no effect on the respiration rate of the bacteria.

According to the EU Risk Assessment (2004) no adsorption onto the organic fraction of soil or sediments is expected, due to the ionic structure under environmental relevant pH conditions. In addition, according to the monitoring data of Virtapohja (2000) (please refer to IUCLID 5, 5.5.1) the concentration of adsorbed EDTA in the sediment is neglible.

Terrestrial compartment

A LC50 -value derived from a 14 days acute test for earthworm was determined to be 158 mg/kg dry weight soil (Edwards, 2009). According to Evangelou et al. (2006) EDTA did not show adverse effect on vegetative vigour of Nicotiana tabacum up to and including an rate of 84 mg/kg soil. An ECx could not be calculated.It has to be considered that due to the water solubility and the hydrophilic character of the substance a binding to the solid soil phase is negligible. Hence EDTA will be preferable expected in the pore water. It could be shown that the substance is enhanced biodegradable in water (see chapter 5.2.1).Therefore no further tests on terrestrial microorganisms are provided.

Conclusion on classification

Based on the results obtained in the toxicity studies and taking into account the provisions laid down in Council Directive 67/548/EEC and CLP, a classification has not to be done.