Edetic acid

Toxicity to terrestrial plants

Administrative data

Endpoint:

toxicity to terrestrial plants: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

no data available

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 227 (Terrestrial Plant Test: Vegetative Vigour Test)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Disodium dihydrogen ethylenediaminetetraacetate

EC Number:

205-358-3

EC Name:

Disodium dihydrogen ethylenediaminetetraacetate

Cas Number:

139-33-3

Molecular formula:

C10H14N2Na2O8

IUPAC Name:

disodium dihydrogen 2,2',2'',2'''-(ethane-1,2-diyldinitrilo)tetraacetate

Test material form:

solid

Sampling and analysis

Analytical monitoring:

not specified

Test substrate

Vehicle:

no

Details on preparation and application of test substrate:

A silty–loamy sand agricultural soil, USDA (Soil Survey Manual), was collected from 0 to 30 cm surface layer of the Melaten field in Aachen, Germany. The soil was air-dried at room temperature, sieved through a 2-mm sieve and characterised as follows:

pH: 6.8
organic matter: 3.5 %
soil fractions
sand: 49.4 %
Clay: 42.1 %
Silt: 8.5 %

Test organisms

Species:

other: Nicotiana tabacum

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Tobacco plants (N. tabacum SR-1) were used for the experiment.

Study design

Test type:

vegetative vigour test

Study type:

laboratory study

Substrate type:

natural soil

Limit test:

no

Total exposure duration:

21 d

Remarks:

approximately 3 weeks

Post exposure observation period:

no data available

Test conditions

Test temperature:

25/20 °C light/dark temperature regime

pH:

6.40 - 6.83

Moisture:

60% relative humidity

Details on test conditions:

16 h light period (light intensity of 320 µmol/m2 * s)

Nominal and measured concentrations:

Nominal: 0.125,0.25, 1.25, 62.5, 125, and 250 mmol/kg for Na2EDTA

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Species:

other: Nicotiana tabacum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 84 - < 420 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Effect concentrations 2

Key result

Species:

other: Nicotiana tabacum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.25 - < 1.25 other: mmol/kg

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Details on results:

EDTA did not show any adverse effects at a concentration of < 0.125 mmol/kg. At 1.25 mmol/kg of EDTA the leaves showed necrotic lesions and the dry weight was negligible. At a concentration of 0.25 mmol/kg EDTA the dry weight is only slightly lower but the standard deviation is higher in comparison to the 0.125 mmol/kg application.

Results with reference substance (positive control):

no data available

Reported statistics and error estimates:

no data availble

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

Based on the results of this vegetative vigour study EDTA had an inhibitory effect on growth of Nicotiana tabacum at rate of 1.25 mmol/kg soil (equivalent to 420 mg/kg). The NOEC will be determined to be 0.25 mmol/kg soil (equivalent to 84 mg/kg soil).

Executive summary:

The effects of EDTA (Na2EDTA) on vegetative vigour of plants following application were examined in a laboratory test on Nicotiana tabacum. The test item was applied at a dose rate of up to 250 mmol/kg and compared to an untreated control.

According to the results, the test item had an inhibitory effect on growth of the tested species at rates of 1.25 mmol/kg soil (equivalent to 420 mg/kg) and thus determined to be the overall LOEC for this species.

The overall NOEC was determined to be 0.25 mmol/kg soil (equivalent to 84 mg/kg).