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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
17 May 2010 to 19 August 2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: compliant to GLP and testing guideline (the deviations observed were not considered to have compromised the validity or integrity of the study); adequate coherence between data, comments and conclusions.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
yes
Remarks:
the temperature varied by more than ± 1°C during the definitive test; water hardness in the control was higher than 250 mg/L as CaCO3 throughout the combined range-finding and limit test and the definitive test
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Perchlorate d'Ammonium
- Substance type: monoconstituent
- Physical state: white powder
- Analytical purity: 99.9%
- Purity test date: 15 March 2010
- Lot/batch No.: A001/10
- Expiration date of the lot/batch: January 2015
- Storage condition of test material: at room temperature and protected from humidity

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Samples were taken at the start of the test in the preparation containers, just before the distribution in the test vessels.
Samples were also taken at T24 hours and at the end of the test (T48 hours) in each replicate directly from the test vessels and then pooled by concentration.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
The stock solutions, for the combined range finding and limit test and definitive tests, were prepared by dissolving the test item directly in M4 medium.
After agitation, the stock solutions were used to prepare the test solutions.
Test solutions were prepared by further dilution of the stock solution with M4 medium to provide a geometric series of concentrations:
- 0.1, 1, 10, 100, 200 and 500 mg/L for the combined range finding and limit test,
- 108, 158, 232, 341 and 500 mg/L for the definitive test.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Strain: Daphnia Magna, STRAUS-clone 5
- Source: LIEBE - CNRS, UMR 7146, Université Paul Verlaine, 57070 Metz, France
- Breeder: CIT
- Age: between 6 and 24 hours old
- Parentage: the parents of daphnids used in the test were born with the same 24 hour period, and had produced at least one brood prior to their use as breeding stock to produced neonates for this test.
- Breeding medium: M4 medium. Reconstituted water prepared according to the OECD guideline for testing of chemicals, N°202, April 2004. The pH of this solution was 8.0 ± 0.5; the sum of Ca and Mg ions in the solution was 2.5 mmol/L (molar ratio Ca:Mg was approximately 4:1 and Na:K approximately 10:1). Temperature was comprised between 18°C and 22°C. Tanks were loaded at one animal/20 mL of culture water.
- Feeding during breeding: animals were fed with a diet of 0.15 mg of carbon per Daphnia per day, in the form of the algal strain Scenedesmus subspicatus which was cultured at CIT and had previously been measured for its total organic carbon content.
- Feeding during test: none

ACCLIMATION
- Acclimation period: none

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h

Test conditions

Hardness:
between 140 to 250 mg/L as Ca CO3
Test temperature:
between 18°C and 22°C (and not varying by more than ± 1°C throughout the test)
pH:
between 6 and 9 and did not vary by more than 1 unit in the control
Dissolved oxygen:
> 3 mg/L at that temperature
Salinity:
Not measured
Nominal and measured concentrations:
108, 158, 232, 341 and 500 mg/L nominal concentrations corresponding respectively to 110, 163, 231, 334 and 489 mg/L at 0 hour and 107, 188, 229, 342 and 502 mg/L, expressed as geometric means of measured concentrations.
Details on test conditions:
TEST SYSTEM
- Test vessel: beakers (150 mL)
- Aeration: none
- Renewal rate of test solution (frequency/flow rate):
- No. of organisms: 20 animals per group divided into four replicate groups of five animals
- Biomass loading rate: 50 mL (10 mL per animal).

OTHER TEST CONDITIONS
- Adjustment of pH: between 6 and 9
- Photoperiod: 16 hour light/8 hour dark

TEST CONCENTRATIONS
- Spacing factor for test concentrations:
- Justification for using less concentrations than requested by guideline:
- Range finding study
- Test concentrations: 0.1, 1, 10, 200, 500
- Results used to determine the conditions for the definitive study: At 24 hours, immobilizations were 0% at 0, 0.1, 1 and 10 mg/L nominal and 5% and 25% at 200 and 500 mg/L nominal respectively. At 48 hours, immobilizations were 0% at 0, 0.1 and 10 mg/L nominal and 15% and 60% at 200 and 500 mg/L nominal respectively. One daphnia died in the test concentration at 10 mg/l but it was considered as an outlier. The 48-hour EC50 of the test item was estimated to be close to 500 mg/L.
Reference substance (positive control):
yes
Remarks:
Potassium dichromate (see the section below)

Results and discussion

Effect concentrations
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 341 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
All validity criteria of the study were respected for each test:
- the immobilization in the control was ≤ 10% at the end of the test,
- the dissolved oxygen concentration remained > 3 mg/L throughout the test.

Measured concentrations in the definitive test solutions were within +/- 20% of the corresponding nominal values throughout the test. The test item was therefore stable under our experimental conditions and the study results were based on nominal concentrations.
Furthermore, samples taken at T0 hours and at T48 hours were analyzed first and since measured concentration were within +/- 20% of the corresponding nominal values (range 97.8 to 102.9%) samples taken at T24 hours were not analyzed.

Any other information on results incl. tables

The results and conclusions of the definitive test are summarized in the following tables:

Group

Control

Perchlorate d’ammonium

Concentration (mg/Lnominal)

0

108

158

232

341

500

 

 

 

Immobilization (%)

24 hours

0

0

0

0

0

20

48 hours

0

0

0

0

20

40

 

Endpoints (mg/L)(1)

 

24 hours

48 hours

EC100

> 500

> 500

EC50

> 341 and close to 500

> 341 and close to 500

EC0/NOEC

≥ 232

≥ 232

(1) EC100: lowest concentration with 100% immobilization; EC50: Median (50%) Effective Concentration (numbers in brackets correspond to the 95% confidence limits); EC0: highest concentration without immobilization

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
In a 48-hour static acute toxicity test with Daphnia magna, the EC50 of Perchlorate d’ammonium was > 341 mg/L and estimated to be close to 500 mg/L according to the combined results of the combined range-finding and limit test and the definitive test.
The No Observed Effect Concentration NOEC was ≥ 232 mg/L.
Executive summary:

Methods

A combined range-finding and limit test (combined range finding and limit test) was performed to determine the concentrations to be tested in the definitive test.

Combined range-finding and limit test

In the limit test, two groups of twenty daphnids (in four replicates of five) were exposed to the test item dissolved in test water at nominal concentration of 0 and 100 mg/L for 48 hours.

In the range-finding test, four groups of twenty daphnids (in four replicates of five) were subjected to dilutions of the limit test solution at 0.1, 1, 10, 200 and 500 mg/L for 48 hours.

Definitive test

In the definitive test, twenty daphnids (in four replicates of five) were exposed to the nominal concentrations of 0, 108, 158, 232, 341 and 500 mg/L for 48 hours.

As the tests were performed in static conditions the solutions remained unchanged for the duration of the test.

Immobilization at each concentration was recorded at 0, 24 and 48 hours.

Chemical analysis

Samples weretaken to measure the concentration of the test item in each test solution of the definitive test, except for the control.

 

Results

All validity criteria of the study were respected for each test.

Measured concentrations in the definitive test solutionswere within ± 20% of the corresponding nominal values throughout the test (Table A, Appendix 3). The test item was therefore stable under our experimental conditions and the study results were based on nominal concentrations.

No difficulty was experienced in discerning the daphnids during the observation periods.

Apart from immobilization, no other adverse effects were observed in the control and treated daphnids.

The 24 and 48-hour EC50s were not calculated since immobilization at the highest concentration (500 mg/L) was lower than 50% at the corresponding time (20, 40%, respectively).

However in the combined range finding and limit test it was observed an immobilization of 60% at T48 hours, therefore it was assumed that the 48-hour EC50 is close to 500 mg/L.

Conclusion

In a 48-hourstaticacute toxicity test with Daphnia magna, the EC50 of Perchlorate d’ammonium was > 341 mg/L and estimated to be close to 500 mg/L according to the combined results of the combined range-finding and limit test and the definitive test.

The No Observed Effect Concentration NOEC was ≥ 232 mg/L.