2-{2-chloro-4-mesyl-3-[(tetrahydrofuran-2-ylmethoxy)methyl]benzoyl}cyclohexane-1,3-dione

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:

24 - 26 Sep 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

04. April 1984, Part I, 24 H EC50 Acute Immobilisation Test

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Hessisches Ministerium für Umwelt, Landwirtschaft und Forsten, Wiesbaden, Germany

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Chemical analyses were conducted at the start and at the end of testing from the untreated control, solvent control (DMSO) and all tested concentrations by chromatographic determination.

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Calculations of the aqueous concentrations of test item were based on 100% purity of the test material. The test item was weighted out to a precision of 0.01 mg and dissolved as a stock solution. The stock solutions for treatment ware prepared by dilution of the first stock solution. Defined amounts of the respective stock solution were added to the corresponding amount of dilution water.
- Chemical name of vehicle: Acetone

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: waterflea
- Strain/clone: Clone 5
- Source: Ecotoxicology lab of Bayer CropScience GmbH
- Age of parental stock: 3 weeks
- Age of Daphnia tested: neonate daphnids (less than 24 hours of age)
- Breeding: Cultured in beakers containing initially 30 adult animals in 2 litre dilution water. Approximately twice a month the parental daphnids were transferred into fresh water resulting in the initial biological loading. Cultures were maintained at 20 ± 2° C and a photoperiod of 16 hours light, 8 hours dark. All cultures were fed with unicellular green algae. Algal cells, grown in nutrient medium, were concentrated by filtration and then resuspended in a small volume of dilution water prior to feeding to the daphnids.
- Feeding during test: no

ACCLIMATION
- Acclimation period: 3 weeks
- Acclimation conditions (same as test or not): yes
- Type and amount of food: Algal cells, grown in nutrient medium
- Health during acclimation: No indications of sub-optimal rearing conditions (e.g. no high mortality, no presence of males or ephippia) were observed

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

174 mg CaCO3/L

Test temperature:

19.5 - 20.8 °C

pH:

7.4 - 7.8

Dissolved oxygen:

8.6 - 9.0 mg O2/L

Conductivity:

470 - 482 µS/cm

Nominal and measured concentrations:

control, solvent control, 10, 18, 32, 56 and 100 mgL (nominal)

Details on test conditions:

TEST SYSTEM
Test vessel:
- Type: closed (covered with glass lids)
- Material, size, headspace, fill volume: 300 mL glass jars (diameter of 95 mm, height of 50 mm) containing 200 mL of test water (head space: 20 mm)
- Aeration: none
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Water used for breeding was the same as used in the test. Dilution water was an artificial mineral medium M4 (Elendt 1990), modified. To prevent precipitation during the preparation of the medium, the chemicals were added to 500-800 mL deionized water and then filled up to 1000 mL. Deionized water used as a basis in all toxicity tests at the testing facility is obtained from a special water supply inside the factory and can be drawn from tap. This water is additionally filtered by a deionization unit and a charcoal filter within the laboratory before use. This medium was prepared and allowed to reach test temperature prior to use.
- Culture medium different from test medium: no
- Intervals of water quality measurement: The temperature of the water bath was recorded continuously during the whole test period in a separate vessel. Dissolved oxygen, pH, water temperature and conductivity were determined initially and at the end of testing in each jar per concentration and in the control groups. The water depth was determined initially and at the end of testing.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light, 8 hours dark
- Light intensity: wide spectrum fluorescent lights

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): observed for immobilisation and behavioural abnormalities at 24 hours
and 48 hours after exposure

VEHICLE CONTROL PERFORMED: yes

OTHER:
- The daphnids were randomly transferred into randomly placed jars filled with the respective exposure solution 70 minutes after the test item was added to the dilution water

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

test item = act. ingr

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: Dwelling near the bottom and slowed reaction were observed as intoxication symptoms in the highest treatment level of 100 mg/L.
- Mortality of control: none
- Other adverse effects control: none

Reported statistics and error estimates:

Since no immobilisation occurred no EC50-calculation was conducted and no concentration-effect relationship was plotted.

Analytical results:

Analyses of freshly prepared water for the test item resulted in test item concentrations ranging from 78.5% to 98.3% of nominal values. Analyses of aged water (48 h) at experimental termination resulted in test item concentrations ranging from 71.3% to 95.6% of nominal values. The mean measured values over the time of exposure ranged from 74.9% to 97.0%. Since recovery percentages below 80% were found at the nominal treatment level of 10 mg/L only and this treatment level is below the range of biological endpoints, all effect concentrations were based on nominal initial test concentrations.

All individual results and mean results are within 80 - 120% of the nominal concentration, except for the lowest concentration level (10 mg/L) on day 0 the result is 78.5% and on day 2 the result is 71.3%. For this concentration the mean result is 74.9% of the nominal concentration. The recovery rates (in the range of 100%) exclude the possibility of an analytical problem.

Biological results:

One individual was immobilised at 56 mg/L. The concentrations estimated to immobilise 50% of the test animals (EC50) after 24 and 48 hours are >100 mg/L. The concentration without any observed effects (NOEC) after 24 hours and 48 hours test duration was 100 and 32 mg/L, respectively.

Table 1: Preparation of test solution

Jar Number	Nominal Concentration in mg/L	Preparation
1 + 2	control	1000 mL dilution water
3 + 4	solvent control	0.1 mL aceton filled up to 1000 mL with dilution water
5 + 6	10	10 mg test item dissolved in and filled up to 1000 mL with dilution water + 0.1 mL acetone
7 + 8	18	18 mg test item dissolved in and filled up to 1000 mL with dilution water + 0.1 mL acetone
9 + 10	32	32 mg test item dissolved in and filled up to 1000 mL with dilution water + 0.1 mL acetone
11 + 12	56	56 mg test item dissolved in and filled up to 1000 mL with dilution water + 0.1 mL acetone
13 + 14	100	100 mg test item dissolved in and filled up to 1000 mL with dilution water + 0.1 mL acetone

Table 2: Validity criteria for OECD 202 (2004)

 

Criterion from the guideline	Outcome	Validity criterion fulfilled
In the control, including the control containing the solubilising agent, not more than 10% of the daphnids should have been immobilized.
The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in control and test vessels.	The dissolved oxygen concentration during the test was at minimum 8.6 mg/L in control and test vessels.	yes

 

 

 

Table 3: Immobilisation and symptoms

 

Nominal concentration (mg/L)	Immobilisation (%)		Symptoms
	24 h	48 h	24 h	48 h
Control	0	0	-	-
Solvent control	0	0	-	-
10	0	0	-	-
18	0	0	-	-
32	0	0	-	-
56	0	5	-	-
100	0	0	-	*
NOEC	100	32

* Dwelling near the bottom and slowed reaction were observed as intoxication symptoms.

 

Validity criteria fulfilled:

yes

Remarks:

See Table 2 in "Any other information on results incl. tables".

Description of key information

EC50 (48 h) > 100 mg/L (nominal) for Daphnia magna (OECD 202)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

> 100 mg/L

Additional information

One key study is available for tefuryltrione, in which the short-term toxicity to invertebrates was investigated. The study was conducted according to GLP and OECD guideline 202. In a static test system in freshwater, the test organism Daphnia magna was exposed to five nominal concentrations of 10, 18, 32, 56, and 100 mg/L. The test concentrations were analytically verified by HPLC. The mean measured values over the time of exposure ranged from 74.9% to 97.0%. All effect concentrations were based on nominal initial test concentrations. One individual was immobilised at 56 mg/L. The concentration estimated to immobilise 50% of the test animals (EC50) after 48 hours was >100 mg/L.