1-cyclohexyl-1H-pyrrole-2,5-dione

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 to 25 January 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

No effect on the integrity of the study.

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Nippon, Lot 5K21
- Expiration date of the lot/batch: 26 May 2018 (Allocated one year from receipt at Chemex)
- Purity test date: 98-100% N-cyclohexylmaleimide (CAS# 1631-25-0), 0-0.2% o-xylene (CAS# 95-47-6)

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: stable
- Stability under test conditions: undergoes hydrolysis
- Solubility and stability of the test substance in the solvent/vehicle: n/a
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: n/a

Analytical monitoring:

no

Details on sampling:

- Concentrations: Duplicate samples were taken at the start and end of the 48 hour exposure period. Samples were taken from remaining
test media after filling test vessels for 0 hours and pooled replicate flasks for 48 hours. Analysis of these samples for the verification of exposure concentrations was performed using HPLC.
-No other samples were taken

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Stock solutions were prepared for both the range-finding and definitive tests by addition of the test sample directly to Elendt M4 medium in a volumetric flask of adequate volume. Calculated volumes of the stock solution were added to nutrient growth medium and made to volume to prepare the test concentrations and provide enough solution for testing and subsequent water quality measurements.
- Eluate: n/a
- Differential loading: n/a
- Controls: Control the same as test solution concentrations
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): n/a
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): n/a
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): n/a

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: Not specified
- Justification for species other than prescribed by test guideline: Not specified
- Source: In stock culture
- Age of parental stock (mean and range, SD): Not specified
- Feeding during test: Not fed during test
- Food type: n/a
- Amount: n/a
- Frequency: n/a

ACCLIMATION
- Acclimation period: no
- Acclimation conditions (same as test or not): n/a
- Type and amount of food: n/a
- Feeding frequency: n/a
- Health during acclimation (any mortality observed): n/a

QUARANTINE (wild caught)
- Duration: n/a
- Health/mortality: n/a

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: n/a

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20.0 - 20.6 °C

pH:

7.17 to 7.79

Dissolved oxygen:

6.85 to 7.27 mg/mL

Nominal and measured concentrations:

Nominal test item concentrations: 0 (control), 0.1, 0.18, 0.32, 0.58 and 1.0 mg/L.
Measured test item concentrations: 0 (control), 0.028, 0.071, 0.173, 0.317 and 0.611 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 40 mL glass dishes
- Type: closed
- Fill volume: 25 mL
- Aeration: no
- Type of flow-through (e.g. peristaltic or proportional diluter): static
- Renewal rate of test solution (frequency/flow rate): Not specified
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): n/a
- Biomass loading rate: n/a

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M4 reconstituted Daphnia water prepared according to OECD 202. Nutrient stock solutions were prepared and added to the dilution water (de-ionised water) to obtain the culture medium. The pH was 7.17 at test initiation
- Total organic carbon: not specified
- Particulate matter: not specified
- Metals: not specified
- Pesticides: not specified
- Chlorine: not specified
- Alkalinity: not specified
- Ca/mg ratio: not specified
- Conductivity: not specified
- Salinity: not specified
- Culture medium different from test medium: no
- Intervals of water quality measurement: 0 and 48 hours

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

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobilisation at 24 and 48 hours exposure time

VEHICLE CONTROL PERFORMED: n/a

RANGE-FINDING STUDY
- Test concentrations: 0 (control), 0.0010, 0.0100, 0.1000, 1.000 and 10.0000 mg/L
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.131 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

ca. 0.071 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 100% immobilisation.

Details on results:

n/a

Results with reference substance (positive control):

n/a

Reported statistics and error estimates:

48hr EC50 range 0.117 - 0.152 mg/L

Validity criteria fulfilled:

yes

Conclusions:

The EC50 for daphnia magna was determined to be 0.131 mg/L.

Executive summary:

This study aimed to investigate the acute toxicity of IMILEX-C to Daphnia magna. The objective of this study was to

determine the 48-hour EC50, which is defined as the concentration that immobilises 50% of the exposed Daphnia after a 48-hour exposure period according to OECD test guideline 202.

Daphnia magna were exposed to varying concentrations of IMILEX-C at 0 (control), 0.1, 0.18, 0.32, 0.58 and 1.0 mg/L with 4 replicates were treatment for a 48 hour exposure period. Observations on Daphnia mobility were performed at 24 and 48 hours after exposure.

The EC50 for daphnia magna was determined to be 0.131 mg/L and the NOEC (100% immobilisation) was 0.317 mg/L

Description of key information

The EC50 for daphnia magna was determined to be 0.131 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.131 mg/L