Potassium; 2-[bis[2-[bis(carboxylatomethyl)amino]ethyl]amino]acetate; iron(3+)

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Study period:

23-1-2013 - 25-1-2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: A GLP study meeting all of the required quality criteria. Analytical certificate present.Validated chemical analysis method used. Appropriate guideline followed. Considered valid without restrictions.

Justification for type of information:

A substantial body of evidence exists that the toxicity profiles of chelates depends mainly on metal ion, its affinity to this metal, and their ability to supply or to sequester it from the body/environment. The source substance has the same chelating agent (DTPA) as in a target substance (DTPA-FeK). The only difference between the target and the source substance is presence of potassium (K) cation instead Na+ cations. As potassium and sodium are the essential macro elements required by all forms of life, is considered not to influence the toxicological activity.

Cross-reference

Reason / purpose for cross-reference:

read-across: supporting information

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

supporting study

Study period:

1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study well documented, meets generally accepted scientific principles, acceptable for assessment; no analytical confirmation of test solutions reported

Justification for type of information:

The underlying hypothesis for the read-across is that chelates have the same mode of action based on their ability to chelate, remove or add metal cations to body causing perturbation of body’s micronutrients balance.
The source substance is a chelating agent in a target substance. The only difference between the target and the main source substance is presence of iron (Fe) and potassium (K) cations instead H+ cations. As iron and potassium are an essential macro- and microelements required by all forms of life, is considered not to influence the toxicological activity.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

read-across source

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Principles of method if other than guideline:

not applicable

GLP compliance:

no

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
not applicable

Analytical monitoring:

no

Vehicle:

not specified

Test organisms (species):

other: Daphnia carinata

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Daphnia carinata
- Source: in-house laboratory bred
- Age of parental stock (mean and range, SD): first instar neonates of Daphnia carinata were used for the study
- Feeding during test: not fed during the experiment

ACCLIMATION
- Acclimation period: not specified
- Acclimation conditions (same as test or not): not specified
- Type and amount of food: not specified
- Feeding frequency: not specified
- Health during acclimation (any mortality observed): not specified

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

not applicable

Hardness:

no data

Test temperature:

20 ± 1 °C

pH:

6.8-7.0

Dissolved oxygen:

> 70% saturation (~ 6.5 mg/l)

Salinity:

no data

Nominal and measured concentrations:

Nominal test solutions for DTPA (free acid) were: 0, 25, 50, 100, 200, 400, 800 mg/L

Nominal test solutions for Fe(III)-DTPA were 0, 31.25, 62.5, 125, 250, 500, 1000 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 ml glass beakers
- Material, size, headspace, fill volume: 100 ml glass beakers with 100 ml of test material
- Aeration: yes
- No. of organisms per vessel: 12
- No. of vessels per concentration (replicates): quadruplicate
- No. of vessels per control (replicates): quadruplicate
- Biomass loading rate: not specified

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Keating's MS animal medium
- Culture medium different from test medium: not specified
- Intervals of water quality measurement: not specified

OTHER TEST CONDITIONS
- Adjustment of pH: yes
- Photoperiod: 16:8 hours light/dark cycle
- Light intensity: not specified

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality

Reference substance (positive control):

not specified

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

342.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: (for DTPA only) 168.5-678.6 mg/l

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

245 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: (for DTPA only) 200-400 mg/l

Details on results:

The 24h LC50 of DTPA to Daphnia carinata was 342.9 mg/l, with the lower and upper 95% fiducial limits being 168.5 and 678.6 mg/l, respectively. There was no mortality after 48 h of exposure to 200 mg/l DTPA, however exposure to 400 and 800 mg/l both resulted in 100% mortality. Consequently, the 48h LC50 was calculated as the geometric mean of the highest and lowest DTPA concentrations giving 0 and 100% mortality, respectively, with the two concentrations in question being the 95% confidence limits. Therefore, the 48-h LC50 of DTPA to Daphnia carinata was 245.0 mg/l (95% confidence limits; 200, 400).

There was no mortality following 24 h exposure to Fe-(III)-DTPA. Furthermore, no significant mortality was observed at any of the Fe-(III)-DTPA concentrations after 48 h, with the highest mortality being 8.7% (mean) at 1000 mg/l, compared to 2.1 ± 2.1% mortality for control daphnids. Daphnids were not exposed to concentrations higher than 100 mg/l Fe-(III)-DTPA (disodium salt dihydrate) due to OECD recommendations that toxicant concentrations not exceed 1000 mg/l in aquatic acute toxicity experiments. This was considered valid for this experiment considering that such high concentrations of Fe-(III)-DTPA are not environmentally relevant. Therefore, both the 24-h and 48-h LC50’s of Fe-(III)-DTPA (disodium salt dihydrate) were concluded to be >1000 mg/l. In terms of Fe-(III)-DTPA alone, the 48h LC50 was > 750 mg/l, based on molecular weight.

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

Probit analysis was only used to calculate the 24-h LC50 of DTPA to Daphnia carinata

Validity criteria fulfilled:

yes

Conclusions:

The 24h LC50 of DTPA to Daphnia carinata was 342.9 mg/l, with the lower and upper 95% fiducial limits being 168.5 and 678.6 mg/l, respectively. There was no mortality after 48 h of exposure to 200 mg/l DTPA, however exposure to 400 and 800 mg/l both resulted in 100% mortality. Consequently, the 48h LC50 was calculated as the geometric mean of the highest and lowest DTPA concentrations giving 0 and 100% mortality, respectively, with the two concentrations in question being the 95% confidence limits. Therefore, the 48-h LC50 of DTPA to Daphnia carinata was 245.0 mg/l (95% confidence limits; 200, 400)

Executive summary:

Following OECD Guideline 202, Daphnia carinata were exposed to Diethylenetriamine pentaacetic acid (DTPA) (free acid) for 48 hours under static conditions. Treatment groups were composed of four replicate beakers containing 100 ml of test solution. Each replicate beaker was stocked with 12 first instar daphnids. Nominal concentrations of DTPA were 0, 25, 50, 100, 200, 400, and 800 mg/L. Mortality (immobility) was observed daily in the test vessels. After 48 hours, no mortality was observed at concentrations of DTPA less than or equal to 200 mg/L. However, after 48 hours, 100% mortality was observed at both 400 and 800 mg/L DTPA. The geometric mean of the highest and lowest DTPA concentrations giving 0% and 100% mortality was calculated as the 48 hr-LC50. Thus, the 48 -hour LC50 was reported as 245 mg/L.

This study also examined the acute toxicity of Fe(III)-DTPA to D. carinata and concluded that the 48 -hour LC50 for Fe(III) - DTPA (disodium salt dihydrate) was > 1000 mg/L.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Sodium hydrogen [N,N-bis[2-[bis(carboxymethyl)amino]ethyl]glycinato(5-)]ferrate(2-)

EC Number:

235-627-0

EC Name:

Sodium hydrogen [N,N-bis[2-[bis(carboxymethyl)amino]ethyl]glycinato(5-)]ferrate(2-)

Cas Number:

12389-75-2

Molecular formula:

C14-H18-Fe-N3-O10.H.Na

IUPAC Name:

Iron(3+) ion sodium 5-[bis(carboxylatomethyl)amino]-3-{[bis(carboxylatomethyl)amino]methoxy}pentanoate

Constituent 2

Reference substance name:

Diethylenetriaminepentaacetic acid, ferric sodium complex

IUPAC Name:

Diethylenetriaminepentaacetic acid, ferric sodium complex

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

Product Name: Dissolvine : De-FE 11
Chemical Name:Diethylenetriaminepentaacetic acid, ferric sodium complex
Purity: 97.2 %
Appearance: Yellow / Green Crystals
Cas Number: 12389-75-2
Project Number:T12050

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

30 ml samples at the start and at the end of the test as well as before and after refreshment were taken and stored in a refrigerator in the dark until
analysis. Stability samples of 100 mg/L in triplicate were also prepared to demonstrate storage stability

Test solutions

Vehicle:

no

Details on test solutions:

The test chemical is easily soluble and prone to light degradation. For this reason a semi static method with solution refreshment was chosen.
A solution of approximately 100 mg/L was made by adding of an accurately weighed amount of the test substance to the test media and stirring until a homogeneous solution was achieved. For both the first and the second stock solutions 0.050 g of the test substance was weighed and dissolved in 500 ml of test medium measured using a volumetric flask.

The test medium was Dutch Standard Water (DSW), with a pH of approximately 8.2, and a conductivity between 550 and 650 µs/cm s-1, containing per
liter of de-ionized water: 200 mg of CaCl2•2H2O, 180 mg of MgSO4•7H2O, 100 mg of NaHCO3 and 20 mg of KHCO3. The guideline criteria requires the CaCO3 content to be between 10 and 250 mg/L. Hardness and conductivity in the test water was measured measured once at the start of the
study as ºdH using the appropriate Dr Lange test kit and converted to the CaCO3 equivalent. Due to the total hardness kit measuring Calcium (as well as magnesium) the test kit was validated by analyzing a known CaCl2 Standard solution.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

The test animals were taken from a Daphnia magna stock, cultured in conformity with the relevant Standard Operation Procedure. The animals used in the test were less than 24 hours old were obtained from parent animals aged between 2-4 weeks. Daphnia were originally obtained from Wil Research Hambakenwetering 7 5231 DD ‘s-Hertogenbosch the Netherlands.

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Remarks on exposure duration:

Refreshment after 24 hours

Post exposure observation period:

None

Test conditions

Hardness:

233.8 mg/L as CaCO3

Test temperature:

22.2 to 22.9 °C

pH:

7.9-8.1

Dissolved oxygen:

8.6-9.2 mg/L

Salinity:

Not Measured

Nominal and measured concentrations:

Nominal = 100 mg/L
Measured Mean = 82.14 mg/L

Details on test conditions:

The test was performed semi static test for 48 hours. 20 animals divided into 4 batches of 5 animals were tested in the control and at the limit test concentration. Those animals which are not able to swim within 15 seconds after gentle agitation of the test vessel were considered to be im¬mobile. The number of animals trapped at the surface was also considered and recorded if observed. These animals were not regarded as im¬mobile and were made to re-submerge. In summary the daphnids were randomly placed in the test fluids and the test vessels were placed in a random manner within each group. The test vessels were not aerated during the test and the animals were not fed. The test was inspected at 0, 24 and 48 hours. The solutions were replaced after 24 hours with freshly made solutions prepared in an identical manner. Animals were carefully transferred using a glass pipette.

As test vessels 50 mL beakers were used containing approximately 50 mL of test solution.

Reference substance (positive control):

yes

Remarks:

The sensitivity of the Daphnia was checked by performing an inhibition test with a reference compound (potassium dichromate) twice a year. The sensitivity was tested for compliance with the guidelines.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 82.14 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No effects of any kind were observed at the limit test concentration.

Results with reference substance (positive control):

The sensitivity of the Daphnia was checked by performing an inhibition test with a reference compound (potassium dichromate) twice a year.
The sensitivity was tested for compliance with the guidelines. Daphnia culture is only released for testing if reference substance criteria are met. This is documented as part of the laboratory GLP system.

Reported statistics and error estimates:

Not applicable. Limit test.

Any other information on results incl. tables

Chemical Analysis Results

Sample Concentration (mg/L) 0 h 24h (old) Geo Mean 24h (new) 48h (old) Geo Mean Time weighted mean Control < LOQ < LOQ - < LOQ < LOQ - - 100 mg/L 97.7 64.9 79.62 101.1 70.9 84.66 82.14

Biological Results

Conc
mg/L (Loading)	0 hours	24 hours	48 hours
Control I	5	5	5
II	5	5	5
III	5	5	5
IV	5	5	5
Total	20	20	20
100    I	5	5	5
II	5	5	5
III	5	5	5
IV	5	5	5
Total	20	20	20

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test substance is considered as non toxic to aquatic invertebrates.