Ethylenediamine-N,N'-di(acetic acid)

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

1.3 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.92 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.13 mg/L

Assessment factor:

100

Extrapolation method:

assessment factor

PNEC marine water (intermittent releases):

0.092 mg/L

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

43 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

no exposure of sediment expected

Sediment (marine water)

Hazard assessment conclusion:

no exposure of sediment expected

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

0.44 mg/kg soil dw

Assessment factor:

100

Extrapolation method:

assessment factor

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

ED2A is mainly produced as intermediate for the production of chelates like EDTA.

There is only limited information available on ED2A which is mainly used for bridging to support the read across from source chemical EDTA to target chemical ED2A. In case of absence of actual measured data for H2 ED2A, the available data from H4 EDTA are read-across to fill the datagaps. All ecotox, fate and phys-chem data from H4 EDTA, Na2H2 EDTA, Na4 EDTA, HEDTA, H2 ED2A etc have been collated in a document which is compiled to justify the read across. This document is included in IUCLID 6, Chapter 13.

The read across is based on strong similaries between the different substances. Each category member has an identical backbone structure which is substituted with 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 of the category several studies have been performed using EDTA acid, Na4 EDTA, Na2H2 EDTA or CaNa2EDTA. The different EDTA species have been used as read-across for the complete category. Since usually only EDTA is measured and monitored which is calculated and expressed as H4EDTA all PNECs are corrected for molar weight and also referred to H4EDTA, edetic acid. A correction for MW has been applied for read across from H4 EDTA to H2 ED2A. Based on the available data is can not be concluded if this approach is justified. The MW correction in any case make the PNEC's lower than for the comparable EDTA complex. Corrections for EDTA/HEDTA have only been applied to correct for the non-toxic counter ion. The read across from H4 EDTA to H2 ED2A is based on the comparability of (eco)toxicity, fate and phys-chem properties observed in the bridging studies.

Summary of the H4 EDTA hazard assessment which is read across to H2 ED2A.

 

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 CaNa2 EDTA on fish was measured in an early life stage study with Brachydanio 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 (or >= 20 mg/L H4 EDTA). Further on, the long-term toxicity of Na2H2 EDTA on Daphnia magn was measured in an reproduction test according to GLP criteria [BASF AG, 1998]. After 21 days of exposure a NOEC of 25 mg/L (or 22 mg/L H4 EDTA) was observed. In addition data of the toxicity of H4 EDTA on the duckweed (Lemna minor)are available. It should be noted that the test substance is a complexing agent which can bind essential micronutrients from the minimal culture medium and that 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 was dependent on the concentration of EDTA and pH.

 

The toxicity of Na2H2 EDTA on microorganisms was tested in an activated sludge respiration inhibition test according to OECD guideline 209 [Ginkel & Stroo, 2000]. The EC20 value after 30 min was measured to be > 500 mg/L (or 429 mg/L H4 EDTA). For Na4 EDTA a similar low toxicity on activated sludge was measured in a 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 of EDTA onto the organic fraction of soil or sediments is expected, due to the ionic structure under environmental relevant pH conditions. This conclusion is supported by monitoring data of Virtapohja (2000) where the concentration of adsorbed EDTA in the sediment is negligible.

Terrestrial compartment

An LC₅₀-value derived from a 14 days acute test for earthworm was determined to be 156 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 (or 73.1 mg/kg dw H4 EDTA). An ECx could not be calculated. It has to be considered that due to the infinite water solubility and anionic properties of the substance a binding to the solid soil phase is negligible. Hence EDTA will be preferable partition to the pore water.

van Ginkel (2017) was able to show that H2 ED2A is biodegradable using river water as inoculum in a prolonged ready test but only after a 84 days >60% biodegradation was observed. Pitter& Sykora were able to demonstrate inherent biodegradability of ED2A in a Zahn-Wellens test. The difference in results is most likely caused by the difference in sludge concentration used in these tests. These results show that ED2A is inherently and ultimately biodegradable. Therefore no further tests on terrestrial microorganisms are provided.

Conclusion on classification

Based on the available results for H4 EDTA and read across applied to H2 ED2A which is justified in the read across document and taking into account the provisions laid down in Council Directive 67/548/EEC and CLP, no classification is considered to be required for H2 ED2A similarly to H4 EDTA. Similar to H4 -EDTA an essential metal depletion of the minimal media is anticipated to be the reason for an ErC10 which is below 1 mg/L