Maleic acid

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

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

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Maleic acid

EC Number:

203-742-5

EC Name:

Maleic acid

Cas Number:

110-16-7

Molecular formula:

C4H4O4

IUPAC Name:

but-2-enedioic acid

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 concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

42.81 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

17.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

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)