Edetic acid

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Remarks:

no GLP

Qualifier:

according to guideline

Guideline:

other: DIN 38412, part 11

GLP compliance:

no

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
Batch No.: 39-1162
purity: > 89%

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The stock solution was prepared by dissolving 2000 mg test substance in dilution water. The test concentrations were then prepared by dilution with test water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: inhouse culture originally obtained from Bundesgesundheitsamt, Berlin
- Age at study initiation (mean and range, SD): < 24h
- Feeding during test : none

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

-

Test temperature:

21 °C

pH:

pH at end of the test:
580 mg/L: 3.85
320 mg/L: 4.02
180 mg/L: 4.40
100 mg/L: 7.30
58 mg/L: 7.73
control: 7.90
580 mg/L pH neutralized: 7.49

Dissolved oxygen:

8.0 - 8.2 mg/L

Conductivity:

658 µS/cm

Nominal and measured concentrations:

Test concentrations (nominal): 58, 100, 180, 320 and 580 mg/L, + 580 mg/L pH neutralized

Details on test conditions:

TEST SYSTEM
- Test vessel: open beaker (50 mL)
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to DIN 38412 L11, 8.2
- Ca/mg ratio: 5:1
- Culture medium different from test medium: no
- Intervals of water quality measurement: The parameters pH, temperature and oxygen concentration were determined at the end of the test.

OTHER TEST CONDITIONS
- Adjustment of pH: no, except for 580 mg/L treatment, which was tesed with and without pH neutralisation
- Photoperiod: 16h light: 8h dark
- Light intensity: 10 µE/qm*s

EFFECT PARAMETERS MEASURED: The number of immobilized animals were recorded after 3, 6, 24, and 48 hours after test start.

Reference substance (positive control):

yes

Remarks:

Potassium chromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

140 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 100-180 mg/L

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

180 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The highest concentration of 580 mg/L showed 100% immobilisation with and without pH neutralisation. Thus, the observed effects cannot clearly be attributed to adversely lowered pH values.

Results with reference substance (positive control):

Reference substance: Potassium chromate
EC50 (24 h): 0.9 mg/L
Date: 12 Sep - 13 Sep 1989

Nominal       Mean number of mobile daphnids after
conc.               24h                   48h     
[mg/L]
-----------------------------------------------------------
 580                    0/20                  0/20     
 320                    0/20                  0/20    
 180                    0/20                  0/20
 100                  20/20                 19/20
  58                   20/20                 19/20
 
control              20/20                 19/20   
pH-control          0/20                  0/20
-----------------------------------------------------------

Validity criteria fulfilled:

yes

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: #1072-69-1
- Purity: 42% (in water)

Analytical monitoring:

yes

Details on sampling:

Samples were collected from each test chamber of each treatment and control group at approximately 0 and 48 hours of the test to measure concentrations of the test substance. All samples were collected from mid-depth in the test chambers, placed in glass scintillation vials and analyzed immediately without storage.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A primary stock solution was prepared by dissolving iron complexed EDT A in Wildlife International, Ltd. well water at a concentration of 120 mgIL, equivalent to the highest concentration
tested. The stock was inverted at least 20 times to mix and appeared clear with a slight yellow color. The four additional test solutions were prepared in well water at concentrations of 16, 26, 43 and 72 mgIL by proportional dilution of the primary stock solution.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): The 16 and 26 mgIL test solutions appeared clear and colorless, whereas the 43, 72 and 120 mgIL test solutions appeared clear with a slight yellow color, increasing in intensity with increasing concentration.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: obtained from cultures maintained by Wildlife International, Ltd., Easton,
Maryland.
- Age at study initiation (mean and range, SD): < 24h
- Feeding during test : none

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

140 mg/L as CaCO3

Test temperature:

10.2 - 20.3 °C

pH:

8.3 - 8.5

Dissolved oxygen:

8.4 - 8.8 mg/L

Conductivity:

315 - 320 µmhos/cm

Nominal and measured concentrations:

Nominal: 16, 26, 43, 72 and 120 mg a.i./L
Measured: 13, 24, 41, 68 and 114 mg a.i./L (> 80% of nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: 250-mL glass beakers containing approximately 200 mL of test solution. Test chambers were indiscriminately placed in a temperature-controlled water bath set to maintain the desired temperature throughout the test.
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The water used for culturing and testing was freshwater obtained from a well approximately 40 meters deep located on the Wildlife International, Ltd. site. The well water was passed through a sand filter to remove particles greater than approximately 25 Ilm, and pumped into a 37,800-L storage tank where the water was aerated with spray nozzles. Priorto use, the water again was· filtered (0.45 Ilm) to remove microorganisms and particles.
- Culture medium different from test medium: no
- Intervals of water quality measurement: Temperature was measured in each test chamber at the beginning of the test, at approximately 24 hours, and at the end of the test using a liquid-in-glass thermometer. Temperature also was measured continuously in one negative control replicate using a Fulscope ERIC Recorder, which was verified prior to test initiation with a liquid-in-glass thermometer. The target test temperature during the study was 20 ± 1 DC. Dissolved oxygen and pH were measured in each test chamber at the beginning of the test, at approximately 24 hours, and at the end of the test. Hardness, alkalinity, specific conductance and total organic carbon (TOC) were measured in the dilution water at the beginning and end of the test. Measurements of pH were made using a Fisher Accumet Model 915 pH meter, and dissolved oxygen was measured using a Yellow Springs Instrument Model51B dissolved oxygen meter. Specific conductance was measured using a Yellow Springs Instrument Model 33 Salinity-ConductivityTemperature meter. Hardness and alkalinity measurements were made by titration based on procedures in Standard Methods for the Examination of Water and Wastewater (4). TOC was measured using a Shimadzu Total Organic Carbon Analyzer, Model TOC-5000.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16h light: 8h dark
- Light intensity: Lighting used to illuminate the cultures and test chambers during culturing and testing was provided by fluorescent tubes that emitted wavelengths similar to natural sunlight. Light intensity at test initiation was approximately 168 lux at the surface ofthe water of one representative test chamber.

EFFECT PARAMETERS MEASURED: Immobility was recorded 24 and 48 hours after test initiation.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 114 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Details on results:

Daphnids in the negative control group appeared healthy and normal throughout the test. Daphnids in the 13,24 and 41 mg/L treatment groups also appeared normal throughout the test with no mortalities, immobile organisms or overt signs of toxicity noted. The NOEC was 41 mg/L. After 48 hours of exposure, mortality/immobility in the 68 and 114 mg/L treatment groups was 5 and 10%, respectively. EC50 values at 24 and 48 hours were estimated to be > 114 mg/L, the highest concentration tested.

Validity criteria fulfilled:

yes

Conclusions:

The 48-hour EC50 value for the cladoceran, Daphnia magna, exposed to iron complexed EDTA was > 114 mg/L, the highest concentration tested.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Justification for type of information:

Category justification document is attached in chapter 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: based on EDTA-Na2H2, -FeNa, -FeK

Description of key information

EC50 (48h) > 100 mg/L for immobilisation of Daphnia magna (WoE, read across)

Additional information

Since no studies are available on invertebrate toxicity of edetic acid (CAS No. 60-00-4), the assessment was based on studies conducted with Subcategory 1a member Disodium dihydrogen ethylenediaminetetraacetate (CAS No. 139-33-3) and Subcategory 1b members Sodium feredetate (CAS No. 15708-41-5) and Ethylenediaminetetraacetic acid iron(III) potassium salt (CAS No. 54959-35-2) as part of a Weight-of-evidence read across approach. This is in accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5. Grouping of substance and read across approach. Further justification for suitability of read across between subcategory 1 members is given within the category justification attached to chapter 13.

The study with Disodium dihydrogen ethylenediaminetetraacetate (CAS No. 139-33-3) was performed according to DIN guideline 38412, part 11 using Daphnia magna as test organism (BASF 1989). Concetrations between 58 and 580 mg/L were tested, The highest test concentration of 580 mg/L were tested with and without pH neutraliation. The higher test concentrations showed markedly lowered pH values throughout the test (180 mg/L: 4.4; 320 mg/L: 4.02; 580 mg/L: 3.85). Immobilisation was mainly observed in these treatments. However, the highest test concentration of 580 mg/L showed 100% immobilisation with and without pH neutralisation. Thus, the effects cannot not only be attributed to lowered pH. The 48h-EC50 value is determined to be 140 mg/L. The study with Sodium feredetate (CAS No. 15708-41-5) was performed according to OECD guideline 202 under GLP using Daphnia magna as test organism (Borrmann 2007). Concentrations between 15 and 240 mg/L were tested. Nominal concentrations were verified analytically. The 48h-EC50 is determined to be 100.9 mg/L. The third study with Ethylenediaminetetraacetic acid iron(III) potassium salt (CAS No. 54959-35-2) was also performed according to OECD guideline 202 under GLP using Daphnia magna as test organism (Palmer et al. 2002). Nominal concentrations between 16 and 120 mg/L were tested and analytically verified (> 80% of nominal). The 48h-EC50 is determined to be > 114 mg/L based on measured concentrations.

Based on the outcome of the various studies available it can be concluded that the 48h-EC50 for edetic acid and other members of subcategory 1 is > 100 mg/L and thus the substances in this subcategory are with a high probability acutely not harmful to aquatic invertebrates.