Trisodium hydrogen ethylenediaminetetraacetate

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-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:

other: EEC Guideline XI/681/86, Draft 4: "Prolonged toxicity study with Daphnia magna: Effects on reproduction"

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples for analysis were taken in the 1st, the 2nd and the 3rd week of the test. For each concentration the freshly prepared test solution (unstocked) and the corresponding 48 h or 72 h old test solution (stocked with daphnids) were analyzed.

Vehicle:

no

Details on test solutions:

At the beginning of the test and before changing the test solutions, a stock solution of the test substance was freshly prepared. A defined amount of the substance was weighed out and suspended directly in the test medium by stirring (about 10 min at 22 ± 1 °C). The nominal concentrations of the stock solutions were 100 mg/L. By dilution of the stock solutions with test medium, the nominal test concentrations were prepared.

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna STRAUSS
Supplier: Institut National de Recherche Chimique Appliquée, France, 1978
Culture: The daphnids are cultured under standard conditions in the Laboratory for Experimental Ecology of BASF AG, Ludwigshafen, Germany

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

Total hardness: 2.20 - 3.20 mmol/L

Test temperature:

19.9 - 21.7 °C

pH:

7.5-8.5

Dissolved oxygen:

Oxygen content: 8.0 - 9.6 mg/L

Nominal and measured concentrations:

Test concentrations (nominal): 100; 50.0; 25.0; 12.5; 6.25; 3.13 and 1.56 mg/L (Dilution factor: 2)

Details on test conditions:

TEST PROCEDURE
- Semistatic procedure: Change of test solution three times a week.
- Test water: synthetic M4-medium
Alkalinity up to pH 4.3: 0.80 - 1.00 mmol/L
Molar ratio Ca:Mg: about 4 : 1
Conductivity: 550 - 650 µS/cm
- Number of animals/vessel: 1
- Number of replicates/concentration: 10
- Number of replicates/control: 10
- Age of the animals at the start of the test: 2 - 24 h
- Age of stock animals: 2 - 4 weeks
- Light: Artificial light, OSRAM L58 W31 warm white day : night-rhythm = 16 : 8 hours
- Removal of young from test beakers and counting: daily
- Check of the study and recording (mortality, hatching of young): daily
- Feeding: daily
- Measurement of temperature: Continuously in an extra vessel
- Measurement of pH and oxygen: At the start of the test and at each change of test solution in the 48 or 72-hour-old solution in one parallel at each concentration

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

other: LC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Reported statistics and error estimates:

For the statistical evaluation of the LOEC and NOEC Duncan's new multiple range test was used.

Analytically found relative minimum and maximum concentrations of the test substance in the test solutions at different times of the test (with and without daphnids). The values are given in percent of the nominal concentrations:

Time [h]	Stocked with daphnids	Minimum [%]	Maximum [%]
0	No	80.8	166.7
48/72	No	92.8	166.7
48/72	Yes	95.2	173.1

 

M4-water caused a background value of about 1 mg/L "Trilon BD". Regarding to this and to the precision of the analytical method, most concentrations found corresponded to the expected values.

 

Validity criteria: In the control:

 - The mortality of parent animals up to the end of the test was <= 10 %.

- The mean number of living young per parent animal that survived the test was >= 60.

- The coefficient of variation for the mean number of living young per parent animal that survived the test was  <= 25 %.

- The NOEC of the control substance 3,4-dichloroaniline was 2.5 µg/L, the LOEC was 10 µg/L and LC0 was > 10 µg/L.

The validity criteria were fulfilled by the test.

 

Control:

In the control the first young were observed at day 7. In the highest concentration tested, at which the daphnids produced young (100 mg/L), the first young were observed at day 13.

Validity criteria fulfilled:

yes

Reference 2

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

Refer to the Analogue Approach Justification document provided in Section 13.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

other: LC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Validity criteria fulfilled:

yes

Description of key information

NOEC (21 d): 25 mg/L (EEC Guideline XI/681/86, Draft 4); read-across

Additional information

Since no studies investigating the long-term toxicity trisodium hydrogen EDTA (CAS 150-38-9) to aquatic invertebrates are available, in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5 a read-across to a structurally related EDTA species was conducted. This read-across is justified in detail in the overall summary (IUCLID Section 6.1) and within the analogue justification in IUCLID Section 13.

The study was performed according to EEC Guideline XI/681/86, Draft 4 (GLP) which is considered to be equivalent or similar to OECD 211. The source substance disodium dihydrogen EDTA (CAS 139-33-3) was used for testing. Daphnia magna was exposed to concentrations of 1.56 to 100 mg/L in synthetic M4-medium under semi-static conditions. The actual exposure concentrations were measured in each week of the test (freshly prepared solutions and 48 h or 72 h old solutions) and approximately corresponded to the nominal values (taking into account the background level of Na2H2-EDTA in the test medium). Thus, the effect concentrations were based on the nominal concentrations. In the test medium the pH-value ranged between 7.3 and 8.5 and the oxygen content between 8.0 and 9.6 mg/L. The total hardness of the medium was 220.2 - 320.3 mg CaCO3/L. In the control the first rising generation was observed at day 7. In the highest concentration tested, the Daphnids produced young (100 mg/L) at day 13. After 21 d a NOEC of 25 mg/L was derived based on reproduction.

In conclusion, the long-term toxicity of trisodium hydrogen EDTA (CAS 150-38-9) to aquatic invertebrates is considered to be in the same range.