4-chlorophenol

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:

1987

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study. All relevant validity criteria were met.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

1981

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

Deviations:

no

GLP compliance:

not specified

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Definitive test: nominal concentrations: 0 (control), 120 - 1000 mg/L nominal exposure concentrations; controls: Test medium without test substance or other additives. Spacing factor determined from range-finding test and physico-chemical properties of the substance.
- Sampling method: Singular samples for possible analysis were taken from all test concentrations and the control according to the schedule:
1. At the start of the test 0-hours from the freshly prepared solutions.
2. The end of the test from the 48-hour old solutions, volume: 1 mL; from the approximate centre of the test vessels.
- Sample storage conditions before analysis: Samples were used on day of sampling

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: For the purpose of the definitive test, the test item was dispersed in DMSO due to limited water solubility. Volumes were then added to ISO-medium to obtain the desired concentration. The concentrations prepared during the range-finding test were then magnetically stirred, after which the respective solutions were used for testing. Preparation during the final test included a magnetic stirring period, which was followed by a stabilisation period. Test solutions were renewed after 24 hours during the final test.
- Eluate: Not applicable.
- Differential loading: Not applicable.
- Controls: Solvent control was used (containing the dispersant only)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): DMSO
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): See above.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): No.
- Other relevant information: Not applicable.

Test organisms (species):

other: Daphnia magna, Daphnia carinata and Daphnia pulex

Details on test organisms:

TEST ORGANISM
- Common name: Daphinds
- Strain (1): Daphnia magna (obtained from a recognised laboratory supplier).
- Strain (2): Daphnia carinata (obtained from a recognised laboratory supplier).
- Strain (3): Daphnia pulex (obtained from a recognised laboratory supplier).
- Age at study initiation (mean and range, SD): < 24 hours.
- Method of breeding: Parthenogenesis
- Feeding during test: No.
- Food type: Not applicable
- Amount: Not applicable.
- Frequency: Not applicable.

ACCLIMATION
- Acclimation period: None.
- Acclimation conditions (same as test or not): Not applicable.
- Type and amount of food: Not applicable.
- Feeding frequency: Not applicable.
- Health during acclimation (any mortality observed): Not applicable.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

24 h

Hardness:

The ISO medium hardness: 56 mg/L expressed as CaCO3 and the pH: 7.7

Test temperature:

The temperature continuously measured in a temperature control vessel varied between 20 +/- 1°C during the test, and complied with the requirements as laid down in the protocol (18-22°C, constant within 2°C).

pH:

Test conditions remained within the limits prescribed by the guideline; pH: 7.7, not varying by more than 1.5 unit at the end of the test.

Dissolved oxygen:

Test conditions remained within the limits prescribed by the guideline; oxygen: >= 3 mg/l at the end of the test.

Nominal and measured concentrations:

Range-finding test: unspecified concentrations; plus Control containing no test substance.
Definitive test: nominal concentrations: 0 (control), 120-1000 mg/L nominal; controls: Test medium without test substance.

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL all glass closed
- Type (delete if not applicable): closed ; semi-static
- Material, size, headspace, fill volume: Glass
- Aeration: No aeration of the test solutions.
- No. of organisms per vessel: Control and test item: 20 per concentration, 5 per vessel containing 50 mL of test solution
- No. of vessels per concentration (replicates): 4 (four replicates, 5 daphnia per vessel).
- No. of vessels per control (replicates): 4 (four replicates, 5 daphnia per vessel).
- No. of vessels per vehicle control (replicates): Not applicable.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Not reported.
- Culture medium different from test medium: No, ISO Medium.

OTHER TEST CONDITIONS
- Adjustment of pH: None.
- Photoperiod: 16h light, 8h dark.
- Light intensity: 1500 lux.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Immobility (including mortality), 24 hours and at 48 hours.

RANGE-FINDING STUDY
- Test concentrations: Not reported.
- Results used to determine the conditions for the definitive study: Yes.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

7.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: D. magna

Remarks:

D. magna

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

12 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: D. carinata

Remarks:

D. carinata

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

10 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: D. pulex

Remarks:

D. pulex

Details on results:

- Behavioural abnormalities: Not reported.
- Observations on body length and weight: Not applicable.
- Other biological observations: None.
- Mortality of control: No mortalities.
- Other adverse effects control: None.
- Abnormal responses: None.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No specific comments made.
- Effect concentrations exceeding solubility of substance in test medium: No.

Results with reference substance (positive control):

- Results with reference substance valid?: Yes.
- Mortality: None. Acute immobilisation observed only.
- EC50/LC50: 24h-EC50 was 7.4 mg/L (D. magna), 12 mg/L (D. carinata), 10 mg/L (D. pulex).
- Other: Not applicable.

Validity criteria fulfilled:

yes

Conclusions:

The test item 24h-EC50 was >1.5 mg/L or the solubility range of the test item based on geometric mean measured average exposure concentrations.

Executive summary:

The acute toxicity to Daphnia magna was carried out according to OECD 202 Daphnia sp., Acute Immobilisation Test, equivalent to EU Method C.2 guidelines. Following preliminary range finding tests using DMSO dispersant to increase water solubility, a definitive study was completed in 100 mL closed glass flasks under semi-static conditions. Preparation of test solutions started with stock solutions in DMSO. Volumes were then added to ISO-medium to obtain the desired concentration. The concentrations were then magnetically stirred, after which the respective solutions were used for testing. Preparation during the final test included a magnetic stirring period, which was followed by a stabilisation period. The definitive test concentrations were 0 (control), and 120 -1000 mg/L nominal exposure concentrations. Twenty daphnids per group (5 per replicate, quadruplicate) were exposed to an untreated control at the specified nominal test substance concentrations. The study met the acceptability criteria prescribed by the protocol and was considered valid. The 24h EC50 was determined to be 7.4 mg/L for D. magna, 12 mg/L for D. carinata, and 10 mg/L for D. pulex.

Description of key information

EC50 -24h (invertebrates) = 7.4 mg/L (lowest value), based on geometric mean measured average exposure concentrations, 24 -hour, freshwater, OECD 202, 1988.

EC50 -24h (invertebrates) = 7.4 mg/L (D. magna), based on geometric mean measured average exposure concentrations, 24 -hour, freshwater, OECD 202, 1988.

EC50 -24h (invertebrates) = 12 mg/L (D. carinata), based on geometric mean measured average exposure concentrations, 24 -hour, freshwater, OECD 202, 1988.

EC50 -24h (invertebrates) = 10 mg/L (D. pulex), based on geometric mean measured average exposure concentrations, 24 -hour, freshwater, OECD 202, 1988.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

7.4 mg/L

Additional information

Key data: OECD TG 202, 1981 : The acute toxicity to Daphnia magna was carried out according to OECD 202 Daphnia sp., Acute Immobilisation Test, equivalent to EU Method C.2 guidelines. Following preliminary range finding tests using DMSO dispersant to increase water solubility, a definitive study was completed in 100 mL closed glass flasks under semi-static conditions. Preparation of test solutions started with stock solutions in DMSO. Volumes were then added to ISO-medium to obtain the desired concentration. The concentrations were then magnetically stirred, after which the respective solutions were used for testing. Preparation during the final test included a magnetic stirring period, which was followed by a stabilisation period. The definitive test concentrations were 0 (control), and 120 -1000 mg/L nominal exposure concentrations. Twenty daphnids per group (5 per replicate, quadruplicate) were exposed to an untreated control at the specified nominal test substance concentrations. The study met the acceptability criteria prescribed by the protocol and was considered valid. The 24h EC50 was determined to be 7.4 mg/L for D. magna, 12 mg/L for D. carinata, and 10 mg/L for D. pulex.