Iron(3+) ion dipotassium 2-({2-[bis(carboxylatomethyl)amino]ethyl} (carboxylatomethyl)amino)acetate; hydrate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

11-16 November 2001

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Done under GLP and with chemical analyses; no certificate of analysis or detailed substance information available.

Justification for type of information:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The results as observed/predicted for EDTA-FeK are read across to EDTA-Fe(OH)K2 as in diluted form in the aquatic environment both EDTA complexes will have a similar structure and related fate.

2. ANALOGUE APPROACH JUSTIFICATION
It is therefore considered justified to use data/predictions as observed for EDTA-FeK also for EDTA-Fe(OH)K2.

3. ANALOGUE APPROACH JUSTIFICATION
Considering the similar structure and the results as observed/predicted for EDTA-FeK, read across of these results to EDTA-Fe(OH)K2 is considered justified as in diluted form in the aquatic environment both EDTA complexes will have a similar structure and related fate.

4. DATA MATRIX
See chapter 13 for Read across document.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples were collected from each test chamber of each treatment and control group at approximately 0 hour, at 48 hours prior to and after test solution renewal, and at 96 hours of the test to measure concentrations of the test substance. All samples were collected at middepth, placed in glass vials, and analyzed immediately without storage.

Details on test solutions:

Test solutions were prepared in the aquaria for each replicate of each treatment group by dissolving a calculated amount of iron complexed EDTA in 15 L of Wildlife International, Ltd well water. The test solutions were stirred with a stainless steel whisk. New test solutions were prepared for renewal at approximately 48 hours. During the test, the 16 mg/L test solution appeared clear and colorless. The 26, 43, 72 and 120 mg/L test solutions appeared clear with a slight yellow color that increased in intensity with increasing concentration.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

The rainbow trout, Oncorhynchus mykiss, was selected as the test species for this study. Rainbow trout are representative of an important group of aquatic vertebrates, and were selected for use in the test based upon past history of use in the laboratory. Rainbow trout used in the test were obtained from Thomas Fish Company, Anderson, California. Identification of the species was verified by the supplier.
The fish were held for at least 14 days prior to the test in water from the same source and at approximately the same temperature as used during the test. During the 14day holding period preceding the test, water temperatures ranged from 11.2 to 12.5°C. The pH of the water ranged from 8.3 to 8.4 and dissolved oxygen ranged from 9.2 to 9.8 mgL (>85% of saturation).
The fish were acclimated to test conditions for approximately 50 hours prior to test initiation. During the acclimation period no mortalities occurred and the fish showed no signs of disease or stress. At test initiation, the rainbow trout were collected from the acclimation tank and impartially distributed one and two at a time to the test chambers until each contained 10 fish.

During the holding period, the fish were fed daily a commercially-prepared diet supplied by Zeigler Brothers, Inc., Gardners, Pennsylvania. The fish
were not fed for at least two days prior to the test or during the test. All fish used in the test were from the same source and year class, and the
standard length of the longest fish measured was no more than twice the length of the shortest. The average standard length of 10 negative control
fish measured at the end of the test was 2.8 cm, with a range of 2.6 to 3.1 cm. The average wet weight (blotted dry) of 10 negative control fish
measured at the end of the test was 0.35 grams, with a range of 0.26 to 0.50 grams. Loading was defined as the total wet weight of fish per liter of
test water and was 0.24 g fish/L

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

no

Hardness:

106 mg/L CaCO3

Test temperature:

11.2-12.5 ºC

pH:

8.2-8.6

Dissolved oxygen:

9.6-10.5 mg O2/L

Salinity:

no data

Nominal and measured concentrations:

nominal concentrations: control, 16, 26, 43, 72, 120 mg/L, chemical analyses showed substance to be within 88-98 % of the nominal values.

Details on test conditions:

Lighting used to illuminate the cultures and test chambers during holding, acclimation and testing was provided by fluorescent tubes that emitted
wavelengths similar to natural sunlight. A photoperiod of 16 hours of light and 8 hours of darkness was controlled with an automatic timer. A
30-minute transition period of low light intensity was provided when lights went on and off to avoid sudden changes in lighting. Light intensity at
test initiation was approximately 594 lux at the surface of the water of one representative test chamber.
Test chambers were 38-L glass aquaria containing 15 L of test solution. The depth of the test water in a representative test chamber was
approximately 12 cm. Temp was set at 12 ºC.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 120 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

Higest tested concentration of 120 mg/L did not induce any effects. So 96-h LC50 > 120 mg/L.

Results with reference substance (positive control):

no reference substance tested

Sublethal observations / clinical signs:

No mortality occurred during the test.

Validity criteria fulfilled:

yes

Conclusions:

96-h LC50 > 120 mg/L
NOEC = 120 mg/L

Executive summary:

LENGTH OF EXPOSURE : 96 Hours

TEST ORGANISMS : Rainbow Trout (Oncorhynchus mykiss)

SOURCE OF TEST ORGANISMS : Thomas Fish Company Anderson, California

AGE OF TEST ORGANISMS : Juveniles

MEASUREMENTS OF 10 NEGATIVE CONTROL FISH : Mean Wet Weight : 0.35 g Range : 0.26 - 0.50 g

Mean Standard Length : 2.8 cm Range : 2.6 - 3.1 cm

Results:

96h LC50 >120 mg/L

NOEC = 120 mg/L

Description of key information

The ecotoxicity of EDTA-FeK is considered to be similar to the ecotoxicity of EDTA-Fe(OH)K2 as both substances will be tested in very diluted form in buffered matrices and under these conditions no significant effects of the additional OH are expected. The ecotoxicity test results as observed for EDTA-FeK will therefore be read across to EDTA-Fe(OH)K2. As a worst-case no molecular weight correction is applied (14% difference).

For EDTA-FeK to toxicity to fish Oncorhynchus mykiss was observed to be LC50 > 120 mg/L (96h. Palmer, 2002, Key study). These results are confirmed by the studies from Ewell (1986) and Borrmann (2007) both performed on EDTA-FeNa where no toxicity was observed upto 100 mg/L. Similar results were found for EDTA-H4 (Batchelder, 1980) and EDTA-Na2H2 (Balk, 1989). In the study from Dow (1976) higher concentration ranges were tested than in the other studies but also here no acute effects were observed to fish upto 120 mg/L

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

120 mg/L

Additional information

Data are available for three short-term studies on fish:

1. A key study with the test substance EDTA FeK is available, according to the guideline and under GLP, semi-static and with rainbow trout. The NOEC (96h) was determined 120 mg/L and the EC50 > 120 mg/L. (key, Palmer 2002).

2. The assessment of the 96 h LC50 of FeNaEDTA in fish was done in an acute test on the rainbow trout Onchorhynchus mykiss according to the OECD Guideline 203, EC method C.1 (92/69/EEC) and US EPA OPPTS 850.1075. The test item was evaluated in a static test under GLP. No mortalities of fish occurred up to a concentration of 100 mg/L within a period of 96 h. The mean measured concentration of the test item was between 80 and 120% of the nominal through the entire test period and the toxicological endpoints were evaluated using nominal concentration of the test item. The LC50 (96h) was determined to be > 100 mg/L with a probability of 99.9%. The NOEC (96 h) was determined to be 100 mg/L.

3. The acute toxicity (96h-LC50) of sodium ferric EDTA towards Pimephales promelas was investigated according to EPA-600/3 -75 -009 and ASTM method E729 -80 in a multispecies test (published paper by Ewel et al, 1986, Reliability 2). The toxicity value was found to be >100 mg/L.