2,6-difluorobenzamide

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

Study period:

2003-01-16 to 2003-03-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study with analytical monitoring

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

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:

2,6-difluorobenzamide

EC Number:

241-972-8

EC Name:

2,6-difluorobenzamide

Cas Number:

18063-03-1

Molecular formula:

C7H5F2NO

IUPAC Name:

2,6-difluorobenzamide

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0, 12.5, 25, 50 and 100 mg/L nominal
- Sampling method: At the start of the test (after 0 h, without daphnids) and at the end of the test (after 48 h) samples from vessels with daphnids were taken.

Test solutions

Vehicle:

no

Details on test solutions:

- Preparation of the stock solution and dilution: The test substance was stirred in M4 medium for about 20 hours at 20 ± 2°C. The concentration of the stock solution was 200,1 mg/2L. By diluting this stock solution with M4 medium the desired nominal concentrations were prepared.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: National de Recherche Chimique Appliquée, France
- Age at study initiation: 2 - 24 h (starting with the 3rd breed of parent animals)
- Age of stock animals: 2 - 4 weeks
- Feeding during test: None

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

2.20 - 3.20 mmol/L

Test temperature:

19.6 - 20.3 °C

pH:

8.0 - 8.2

Dissolved oxygen:

8.7 - 9.1 mg/L

Nominal and measured concentrations:

Nominal: 12.5, 25, 50 and 100 mg/L
Measured concentrations were within ± 5 % of the nominal values. Therefore, the results were based on nominal concentrations.

Details on test conditions:

TEST SYSTEM
- Test vessel: Covered beakers with a nominal volume of 100 mL
- Fill volume: 50 mL
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: According to guideline
- Intervals of water quality measurement: At test start and at test end

OTHER TEST CONDITIONS
- Photoperiod: day:night rhythm = 16 : 8 h
- Light intensity: About 1 to 8 µE/(m2*s) at a wave length of 400 - 750 nm

EFFECT PARAMETERS MEASURED: Mobility

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Mortality of control: None

Any other information on results incl. tables

Measured concentrations confirm the nominal values. Therefore, the following results were based on nominal concentrations.

No sublethal effects could be observed. No other effects were observed.