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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Administrative data

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:
other: GLP guideline study, the substance caused a decrease in pH of the test solution at the highest test concentration. The test was repeated with the highest test concentration (pH was adjusted).

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
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): Maleic acid
- Analytical purity: 99.7 %
- Lot/batch No.: LPMS3A1015

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: control, 10 mg/L and 93.8 mg/L

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: a stock solution was prepared by dissolving 250 mg test substance in 25 ml test water. The test concentrations were prepared by separately by diluting the required amount of stock solution.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Source: the test animals were bred at the testing facility
- Age at study initiation (mean and range, SD): < 24 hours
- Food type (breeding culture): green algae (Chlorella vulgaris)

Study design

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

Test conditions

Test temperature:
20.3 and 20.4 ºC
pH:
control up to a test substance concentration of 53.6 mg/l: 6.13 - 7.89
at a test substance concentration of 93.8 mg/l: 4.13 - 4.17
repeated test with a test substance concentration of 93.8 mg/l: 7.61 - 7.66
Dissolved oxygen:
6.0 - 7.2 mg/l
Nominal and measured concentrations:
Nominal test concentrations:
control, 10, 17.5, 30.63, 53.60, 93.80 mg/l
The test was repeated with the hightest test concentration of 93.80 mg/l. The pH of the test medium was adusted to pH 6-9

Measured test concentrations:
10.11, 101.60 mg/l
98.3413 104.8511
Details on test conditions:
TEST SYSTEM
- Test vessel: glass beaker (250 ml)
- Fill volume: 150 ml
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 2 ml/animal


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water according to OECD guideline 202


OTHER TEST CONDITIONS
- Adjustment of pH: yes at 93.80 mg/l
- Photoperiod: continous darkness

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Mobility at 0, 24 and 48 hours

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.75
- Test concentrations: 0.1, 1, 10, 100 mg/l
- Results used to determine the conditions for the definitive study: no immobility at 0.1, 1 and 10 mg/l; 100 % immobility at 100 mg/L at 24 hours and 48 hours.
Reference substance (positive control):
yes
Remarks:
Potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
42.81 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
17.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
LOEC
Effect conc.:
30.63 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
The substance caused a decrease of the pH in the test medium. This caused an immobilisation by 100 % at the highest test concentrations. In the repeated test with pH adjustment 55 % of the test animals were immobile at 93.80 mg test substance /l.
Reported statistics and error estimates:
EC50 was determined by Probit analysis (Finney 1971)

Applicant's summary and conclusion