Ethyl difluoroacetate

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:

other: GLP guideline study with analytical monitoring

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Ethyl difluoroacetate

EC Number:

207-223-4

EC Name:

Ethyl difluoroacetate

Cas Number:

454-31-9

Molecular formula:

C4H6F2O2

IUPAC Name:

ethyl difluoroacetate

Details on test material:

- Name of test material (as cited in study report): ethyl difluoroacetate
- Physical state: Liquid/colorless, clear
- Analytical purity: 99.9%
- Batch No.: 33244/106 A

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The container with the test substance was shaken to homogenise the test substance. The test solutions were prepared by adding 1000 mg test substance to 1000 ml test medium (M4 medium). The mixture was stirred for about 10 min at 20 °C. The stock solution appeared colourless-clear. By dilution of this stock solution with M4 medium the test concentrations were prepared.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: supplied by the Institut National de Recherche Chimique Appliqueé, France, in 1978. From this date on this clone was cultured and bred continuously in the Laboratory of BASF SE in Ludwigshafen
- Age at study initiation: <= 24 h (at least third brood progeny)
- Feeding during test: none

HOUSING
- Photoperiod: 16 h light, 8 h darkness
- Type of food: unicellular algae Desmodesmus subspicatus
- Feeding frequency: daily
- Renewal of culture water: Twice weekly

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

2.48 mmol/L

Test temperature:

20-21 °C

pH:

7.5 - 8.0

Dissolved oxygen:

Study initiation: 8.6 - 8.8 mg/L
Study end: 5.9 - 8.1 mg/L

Nominal and measured concentrations:

Nominal test concentrations: control, 0.5, 1.0, 2.2, 5.0, 10 mg/L
Measured test concentrations: the substance is not stable in M4-medium, concentrations of the test substance were not detectable

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: closed (substance was volatile)
- Material, nominal volume, fill volume: glass tubes sealed with gas impermeable teflon caps, 23 ml, approx. 23 ml
- Aeration: none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 0.22 animals/ml

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: synthetic fresh water (Elendt M4 medium)
- Alkalinity: 0.88 mmol/L
- Conductivity: 606 µS/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: pH and oxygen content after 0 and 48 h; temperature continuously

OTHER TEST CONDITIONS
- Photoperiod: 16 h light : 8 h darkness
- Light intensity: about 20 - 850 lux at a wave length of 400 - 750 nm

EFFECT PARAMETERS MEASURED: mobility after 0, 24, 48 h

TEST CONCENTRATIONS
- Range finding study: yes
- Results used to determine the conditions for the definitive study: EC50 (48 h) between 1.0 and 10 mg/L

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

2.2 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.:

6.9 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.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

EC50 (24 h) = 1.17 mg/L
(control experiment from 26 Nov 2007)