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

Toxicity to aquatic plants other than algae

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic plants other than algae

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

no data available

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: acceptable, well documented study

Justification for type of information:

Study is read across and slightly updated and presented under "type of information" as experimental study until the lead company has updated the Source RSS
Read across justification is presented in IUCLID chapter 13

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 221 (Lemna sp. Growth Inhibition Test)

Deviations:

not specified

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

Lemna minor

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

7 d

Effects of pH and EDTA on the relative growth rate of Lemna minor

pH-value	Concentration of EDTA (µM/L)
	0	40	80	100	200
5.0	12.6	12.6	15.8	19.4	19.8
6.0	12.3	11.9	14.8	15.8	15.7
7.0	15.5	18.9	15.2	13.0	10.2

Validity criteria fulfilled:

not specified

Conclusions:

The growth of Lemna minor was affected by pH. In test sets supplemented with EDTA between 40 und 200 µM concentrations, growth inhibition was observed in the test medium with adjusted pH of 7.0 at EDTA concentration of 100 µM and higher.

Executive summary:

The growth of Lemna minor was determined after 7 days of exposure. Based on the results growth of duckweed was affected by pH. In test sets supplemented with EDTA between 40 und 200 µM concentrations, growth inhibition was observed in the test medium with adjusted pH of 7.0 at EDTA concentration of 100 µM and higher.

Description of key information

No data on Toxicity to aquatic plants other than algae is available for H2 ED2A. Consistent with the other ecotoxicity endpoints, the available data from H4 EDTA are read-across to fill the datagap. For justification of the read-across see IUCLID 6, Chapter 13.

The toxicity of H4 EDTA on the duckweed Lemna minor has been evaluated according to a guideline which is equivalent to OECD TG 221.

The growth of Lemna minor was quantified after 7 days of exposure. Based on the results growth of duckweed was affected by pH. In test sets supplemented with EDTA between 40 und 200 µM concentrations, growth inhibition was observed in the test medium with adjusted pH of 7.0 at EDTA concentration of 100 µM and higher.

Key value for chemical safety assessment

EC10 or NOEC for freshwater plants:

29.2 mg/L

Additional information

No data on Toxicity to aquatic plants other than algae is available for ED2A-H2. Consistent with the other ecotoxicity endpoints, the available data from EDTA are read-across to fill the datagap. For justification of the read-across see IUCLID 6, Chapter 13.

The toxicity of H4 -EDTA on the duckweed Lemna minor has been evaluated according to a guideline which is equivalent to OECD TG 221.

The growth of Lemna minor was quantified after 7 days of exposure. Based on the results growth of duckweed was affected by pH. In test sets supplemented with EDTA between 40 und 200 µM concentrations, growth inhibition was observed in the test medium with adjusted pH of 7.0 at EDTA concentration of 100 µM and higher.

It should be noted that the culture medium used in this test for Lemna minor is like the OECD culture medium for algae a minimal medium which means that H4 -EDTA like ED2A-H2 can reduce the bioavailability of essential micronutrients in the culture medium to a level where growth is limited. This indirect nutrient deficiency effect is an artefact and should not be used for the effect assessment because it is unlikely to occur in the environment (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 this study. Data revealed that growth were dependent on the concentration of EDTA and pH.