diethyl 1-(2,4-dichlorophenyl)-5-methyl-4,5-dihydro-1H-pyrazole-3,5-dicarboxylate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28 Oct - 4 Nov 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: To obtain fresh stock solution for the test, the test substance was weighed out to a precision of 0.1 mg and diluted with a maximum of 0.1 mL acetone/L water as a solvent (amount of solvent calculated to the water volume of the test tanks). Defined amounts of stock solution and solvent were pipetted proportionally into the filled tanks and stirred vigorously with a dissolver (ULTRA-TURRAX).
- Chemical name of vehicle: Acetone (applied abbreviation= A, Riedel-de Haen AG, Seelze, Art.No.32201, assay 99.5%, lot 6057)
- Concentration of vehicle in test medium: 0.1 mL per liter water.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: Mirror Carp
- Source: Rheinisch- Westfaelische-Elektrizitatswerke, Limnothermanlage, Bergheim, Federal Republic of Germany on May 07, 1991 and then maintained in the fish maintenance room of the Ökotoxikologie (Ökologie I) of Hoechst AG.
- Age at study initiation: Seven months
- Length at study initiation: 3.67 cm
- Weight at study initiation: 1.56 g
- Feeding during test: No


HOUSING
Conditions: The fish were maintained in accordance with the procedures described by Brauhn, Schoettger and Mueller (1975) in fibre-glass tanks. The fish were maintained with a mean water flow of 408 (min. 240, max. 480) L/h, a mean temperature of 21.3 (min. 18.4, max. 22.6) °C, a mean pH of 7.72 (min. 7.42, max. 7.9), and a mean dissolved oxygen concentration of 8.0 (min. 6.2, max. 9.3) mg/L.
- Type and amount of food: Standard trout food (Roth, Kirchhain, FRG) or TETRA MIN (Zoozentrum Hoechst, Frankfurt 80, FRG)
- Feeding frequency: 6 times a week
- Health during acclimation: No mortality occurred in the stock culture over a 14-day period before initiating the study.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

210 mg/L expressed as CaCO3.

Test temperature:

22 ± 1 °C

pH:

8.2 - 8.5

Dissolved oxygen:

8.2 - 9.2 mg/L

Salinity:

-

Nominal and measured concentrations:

The nominal concentrations were: 0 (dilution water control), 0 (solvent control 0.1 ml/L acetone), 0.32, 0.56, 1.0, 1.8, 3.2, 5.6, 10, and 18 mg/L test item.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 300 L stainless steel tanks containing 200 L dilution water.
- Aeration: yes
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): 1
- Biomass loading rate: 0.08 g7L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The dilution water was a mixture of 60% filtered tap water and 40% deionised water
- Intervals of water quality measurement: The water temperature of the untreated control were recorded continuously during the whole test period. Dissolved oxygen, pH and water temperature were determined initially and every 24 hours thereafter for each vessel. Conductivity was measured in the same vessels initially and at the end of testing.


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: light-dark cycle 16H/8D
- Light intensity: wide spectrum fluorescent lights


EFFECT PARAMETERS MEASURED : The fish were examined daily for signs of intoxication and mortality.

Reference substance (positive control):

not specified

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

2.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Other biological observations: As intoxication symptoms 24 hours after starting the test slow reactions, surface or lateral swimming,
equilibrium disturbances and cramps were noted in the concentrations equal to and greater than 1.8 mg/L.

Sublethal observations / clinical signs:

Based on analytically verified nominal concentrations, the static 96h LC50 for the mirror carp was calculated

to be 2.4 mg/L. The NOEC was 1.0 mg/L. The NOEC to clinical signs was > 1.8 mg/L.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

14 - 21 Jun 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: stock solution: 5000 mg test substance dissolved into 50 mL acetone
- Chemical name of vehicle: Acetone (applied abbreviation= A, Riedel-de Haen AG, Seelze, Art.No.32201, assay 99.5%, lot 6057)
- Concentration of vehicle in test medium: 0.1 mL per liter water.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Source: Trout hatchery Miller, Fredelsloh, FRG
- Age at study initiation (mean and range, SD): 3 months
- Length at study initiation: 5.31 cm
- Weight at study initiation: 2.13 g
- Feeding during test: no

HOUSING:
- Type and amount of food: standard trout food (Roth, Kirchhain, FRG) or TETRA MIN (Zoozentrum Hoechst, Frankfurt a.M. 80, FRG) .
- Feeding frequency: Food served 5 times a week
- Health during acclimation: There was no mortality in the stock culture over a 14-day period before initiating the test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

210 - 223 mg/L as CaCO3

Test temperature:

13.0 - 14.4 °C

pH:

8.2 - 8.3

Dissolved oxygen:

7.8 - 10.6 mg/L

Salinity:

-

Nominal and measured concentrations:

Nominal test concentrations: untreated control, 0.32, 0.56, 1.0,
1.8, 3.2, 5.6, and 10 mg/L.
Chemical analysis of the freshly prepared and aged test solutions was performed for the nominal test concentration of 0.32, 1.8 and 10.0 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 300 L stainless steel tanks containing 200 L dilution water.
- Aeration: no
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): 1
- Biomass loading rate: 0.11 g/L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The dilution water was a mixture of 60% filtered tap water and 40% deionised
water with a total water hardness of 210 mg/L expressed as CaCO3
- total alkalinity mg/L as CaCO3: 161 - 160
- calcium content mg/L: 68.7 - 67.7
- magnesium content mg/L: 11.2 - 11.9
- nitrite content mg/L: < 0.05


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: the light dark cycle 16H/8D
- Light intensity: wide spectrum fluorescent lights


EFFECT PARAMETERS MEASURED: The fish were examined daily for signs of intoxication and mortality, and the mortality rates were used to calculate the 24, 48, 72 and 96-hour LC50 values. Dissolved oxygen, pH and temperature were measured throughout the study.

Reference substance (positive control):

not specified

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

4.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Other biological observations:
- As intoxication symptoms: 24 hours after starting the test slow reactions, narcotic conditions, horizontal turns, deformation, surface-head-up- and or cramped swimming were noted in the concentrations of and above 1.8 mg/L.

Sublethal observations / clinical signs:

Based on analytically verified nominal concentrations, the static 96h LC50 for the rainbow trout was calculated

to be 4.2 mg/L. The NOEC was 1.0 mg/L and due to clinical signs at concentrations > 1.8 mg/L.

Description of key information

LC50 (96h) = 2.4 mg/L with Cyprinus carpio (nominal, OECD 203)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

2.4 mg/L

Additional information

Two studies on the parent substance were performed in order to evaluate the effects of short term toxicity to fish. All studies referred to herein were conducted in accordance with OECD testing guideline 203 and GLP. The study conducted with the test item resulting in the most sensitive LC50 value was chosen as key study.

In the key study Cyprinus carpio were exposed to the test item in a static test design to a nominal concentration range of 0.32 to 18 mg/L and two controls (1992). Acetone was used as vehicle. The static 96h LC50 for the mirror carp was calculated to be 2.4 mg/L (nominal).

In the second study conducted with the test substance Oncorhynchus mykiss were exposed under a static test regime to a concentration range of 0.32 to 10 mg/L using acetone as vehicle (1991). The static 96h LC50 was calculated to be 4.2 mg/L (nominal).

Supporting information on the toxicity of three different metabolites of the test item is available.

Two supporting studies investigating the acute toxicity of one metabolite of the parent substance are available. One study was conducted with Oncorhynchus mykiss in a static system using DMSO as vehicle (1997). Based on the nominal substance concentration a LC50 (96 h) > 100 mg/L was determined. The second study was conducted with Danio rerio under flow-through conditions (2005). A range of concentrations between 1 to 100 mg/L was tested. The determined LC50 (96 h) was > 72 mg/L based on mean measured concentrations.

A supporting study on a second metabolitewas conducted as a limit test at a nominal substance concentration of 100 mg/L with Oncorhynchus mykiss as test species (1999). The static 96h LC50 was calculated to be > 100 mg/L (nominal).

A further supporting study on a third metabolite was conducted as a static test with Lepomis macrochirus (2002). Concentrations from 10 to 100 mg/L were tested. The 96h LC50 was calculated to be > 100 mg/L (nominal).

The available data indicate a acute toxicity of the substance to fish.