Chlorimuron ethyl

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1984

Report date:

1984

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

The acute toxicity of the test material to Daphnia magna, was determined under static, unaerated test conditions during a 48-hour exposure period at test concentrations up to 1333 mg/L. Immobility counts and observations were made at 24 and 48 hours after the exposure was initiated.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

ethyl 2-({[(4-chloro-6-methoxypyrimidin-2-yl)carbamoyl]amino}sulfonyl)benzoate

EC Number:

618-690-2

Cas Number:

90982-32-4

Molecular formula:

C15H15ClN4O6S

IUPAC Name:

ethyl 2-({[(4-chloro-6-methoxypyrimidin-2-yl)carbamoyl]amino}sulfonyl)benzoate

Test material form:

solid

Details on test material:

Purity: 96%

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

yes

Remarks:

Well water

Details on test solutions:

- Procedure:
The test material, prepared as 1 and 1.333 g/L stock solutions with enough NaOH solution added to raise the pH to 9 to implement solubility of the material received, was diluted with laboratory mass culture well water to yield the desired exposure concentrations. After mixing, 200 mL volumes of each concentration were introduced into each of two separate 250 ml glass exposure vessels. Two identical vessels containing only laboratory mass culture water were designated as H20 controls.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Source: In-house bred
Food: Food was not provided during the test
Stability: Not determined

Study design

Test type:

static

Water media type:

other: Fresh water

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

Immobility counts and observations were made at 24 and 48 hours after the exposure was initiated

Test conditions

Test temperature:

19.9 and 20.3°C

pH:

9

Nominal and measured concentrations:

Nominal concentrations: 100, 130, 180, 240, 320, 420, 560, 750, 1000 and 1333 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 2 seperate 250 mL exposure vessels
- Aeration: No
- Type of flow-through: Static
- No. of organisms per vessel: 10 daphnids

OTHER TEST CONDITIONS
- Adjustment of pH: Enough NaOH solution added to raise the pH to 9
- Photoperiod:16 hours light and 8 hours dark

VEHICLE CONTROL PERFORMED: yes

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% confidence limits of 920 and 1150 mg/L

Details on results:

The chemical and physical parameters measured during the test are within the acceptable ranges for this study

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

48-Hour EC50: 1000 mg/L (Mortality)

Executive summary:

The acute toxicity of the test material to Daphnia magna, was determined under static, unaerated test conditions during a 48-hour exposure period at test concentrations up to 1333 mg/L.

Immobility counts and observations were made at 24 and 48 hours after the exposure was initiated.

Test substance exhibited low acute toxicity to Daphnia magna under the test conditions during a 48-hour exposure period. Solubility of the test substance in water was obtained by adding NaOH solution to a pH of 9. The 48-hour EC50 was calculated to be 1000 mg/L, with 95% confidence limits of 920 and 1150 mg/L.