3-methyl-1-phenyl-5-pyrazolone

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:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3-methyl-1-phenyl-5-pyrazolone

EC Number:

201-891-0

EC Name:

3-methyl-1-phenyl-5-pyrazolone

Cas Number:

89-25-8

Molecular formula:

C10H10N2O

IUPAC Name:

5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one

Sampling and analysis

Analytical monitoring:

yes

Remarks:

HPLC-UV

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna (Straus), clone 5, from 6.0 to 22.25 hours old, female.

Study design

Test type:

static

Water media type:

other: reconstituted water (Elendt "M4")

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

Not specified

Test conditions

Hardness:

2.5 mmol/L (=250 mg/L) as CaCO3

Test temperature:

19.3 to 20.9°C

pH:

6.1 to 6.4

Dissolved oxygen:

8.2 to 9.2 mg/L

Nominal and measured concentrations:

Nominal concentrations: 10, 4.5, 2.1, 0.94, 0.43 mg test item/L
Measured concentrations: 9.55, 4.31, 1.99, 0.601, 0.375 mg test item/L

Details on test conditions:

Photoperiod: 16h light-8h dark; Light intensity: 530 to 610 lux

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

4.81 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.601 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Key result

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

1.99 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

All reported results refer to geometric mean concentrations since the test item concentrations were not within +/- 20% of the nominal concentrations during the test.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The toxic effect of the test item Pyrazol to Daphnia magna was assessed in a static concentration-response test. The 48-hour NOEC was determined to be 0.601 mg test item/L. The 48-hour LOEC was determined to be 1.99 mg test item/L and the 48-hour EC50 value was calculated to be 4.81 mg test item/L (results refer to geometric mean concentrations).