N-[2,5-dichloro-4-(1,1,2,3,3,3-hexafluoropropoxy)-phenyl-aminocarbonyl]-2,6-difluorobenzamide

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 Feb 1989 to 24 Feb 1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1984

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples for analysis were taken at the start and at the end of the exposure.

Vehicle:

yes

Remarks:

1- methyl-2-pyrrolidon

Details on test solutions:

- Stock solution: 12.0 g of the test substance were mixed and made up to 50 mL with 1-methyl-2-pyrrolidoon NMP
- Treatment groups: Calculated amounts of test substance to produce the desired test concentrations were given into the water and were homogeneously distributed. A slight deposit was observed at conc. 10 -100 mg/L (nominal) from the start of the test.
- Blank control: water
- Vehicle control: 363.5 mg 1- methyl-2-pyrrolidon per liter water in the concentration used for the highest test concentration

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

TEST ORGANISM
- Common name: Bluegill
- Length at study initiation: 34 mm (30 – 41 mm)
- Weight at study initiation : 0.45 g (0.29 – 0.69 g)
- Feeding during test: None
- Adaptation: 24 hours / no food 24 hours prior to exposure

ACCLIMATION
- Acclimation period: 45 days

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

167 mg CaCO3/L

Test temperature:

23 ± 1 °C

pH:

- At the start of the test: 7.7 – 7.9
- At the end of the test : 8.2 – 8.4

Dissolved oxygen:

- At the start of the test: 100 – 102% of saturation
- At the end of the test : 90 – 98% of saturation

Nominal and measured concentrations:

- Nominal concentrations: 10, 18, 32, 58, and 100 mg/L
- Measured concentrations: 4.9, 5.0, 11, 12 and 29 mg/L, respectively

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass aquaria of 20 L
- Fill volume: 15 L (36/22/25 cm)
- Aeration: Gentle aeration during the test
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Loading: 0.30 g/L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dechlorinated tap water (carbon filter)
- Intervals of water quality measurement: Oxygen, pH, temperature were measured daily

OTHER TEST CONDITIONS
- Light source: Fluorescent light
- Photoperiod: 16 hours light and 8 hours darkness

EFFECT PARAMETERS MEASURED
- Mortality: The number of dead fish was counted every 24 hours.
- Symptoms observation: The swimming behaviour, loss of equilibrium, respiratory function, exophtalmus and pigmentation ofthe fish were observed every 24 hours.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 29 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Details on results:

An overview of the results is provided in Table 1 in 'Any other information on results incl. tables'.
After 96 hours exposure, one fish was dead (10% mortality) in the blank control group. All fish in other groups were survived and no signs of toxicity were observed during the study period.

Sublethal observations / clinical signs:

Table 1. Acute toxicity to bluegill sunfish

Nominal concentration (mg /L)	Actual initial concentration (mg/L)	Mortalities
		24h	48h	72h	96h
Control	-	0	0	0	1
Vehicle control	-	0	0	0	0
10	4.9	0	0	0	0
18	5	0	0	0	0
32	11.3	0	0	0	0
58	12.3	0	0	0	0
100	29.3	0	0	0	0

Validity criteria fulfilled:

yes

Conclusions:

In an acute aquatic toxicity study performed in accordance with OECD TG 203, the 96-hour LC50 was determined to be > 29 mg/L.

Executive summary:

The acute toxicity of the test substance to the bluegill, Leopomis macrochirus, was conducted according to the OECD TG 203 guideline and in compliance with GLP. Groups of 10 fish/ test vessel (length 30-41 mm; weight 0.29-0.69 g; 1 replicate) were exposed to nominal concentrations of 10, 18, 32, 58, and 100 mg/L test substance solution (measured initial concentrations: 4.9, 5.0, 11, 12 and 29 mg/L, respectively) in a static system for 96 hours. In addition, a blank control (dilution water) and a vehicle control (1- methyl-2-pyrrolidon) groups were included in the study as well under the same testing conditions. The test was carried out at 23 ± 1˚C, 167 mg CaCO3/L water hardness, pH 7.7 – 8.5 and oxygen concentration 73 – 102 % saturation.  The concentrations of the test solutions were determined by liquid chromatography at 0 and 96 hours. The mortality and symptoms of toxicity (i.e. swimming behaviour, loss of equilibrium, respiratory function, exophtalmus and pigmentation) of the fish were recorded daily.

The mean measured concentrations of the test substance were in the range 21 to 125% of nominal. The measured initial concentrations of the test substance were therefore used for the calculation and reporting of results. After 96 hours exposure, only 1 fish was dead (10% mortality) in the blank control group. All fish in other groups were survived and no signs of toxicity were observed during the study period. Therefore, the LC50 was determined to be > 29 mg/L (the highest tested concentration) based on initial measured concentrations.

Description of key information

All available data was assessed. The study representing the worst-case effects was included here and its effect value was used as the key value. Other studies are included as supporting information.

Freshwater, 96-h LC50 > 29 mg/L, Lepomis macrochirus, OECD TG 203, Rufli 1989a

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

> 29 mg/L

Additional information

There are four standard guideline and GLP-compliant studies available for this endpoint. All these studies followed OECD TG 203 and compliant with GLP. The 96-h acute toxicity study (Rufli 1989a, Reliability 2) on bluegill fish (Leopomis macrochirus) was selected as key study, because it represents the worst-case effects (i.e. showed the lowest LC50 value). The fish were exposed to nominal concentrations of 10, 18, 32, 58, and 100 mg/L test substance solution (measured initial concentrations: 4.9, 5.0, 11, 12 and 29 mg/L, respectively) in a static system. In addition, a blank control (dilution water) and a vehicle control (1- methyl-2-pyrrolidon) groups were included in the study as well.

The mortality and symptoms of toxicity (i.e. swimming behaviour, loss of equilibrium, respiratory function, exophtalmus and pigmentation) of the fish were recorded daily. After 96 hours exposure, only 1 fish was dead (10% mortality) in the blank control group. All fish in other groups were survived and no signs of toxicity were observed during the study period. Therefore, the LC50 was determined to be > 29 mg/L. The other three studies on different species are included as supporting studies. In these studies, Catfish (Ictalurus punctatusi), rainbow trout (Salmo gairdneri) and Common Carp (Cyprinus carpio) were exposed to the test substance in a static system for 96 hours up to 100 mg/L nominal. No mortality or sign of toxicity was observed during the study period. Based on the findings, the 96-hour LC50 value was determined to be > 45 mg/L for Catfish (Rufli, 1989b), LC50 > 73 mg/L for Common carp (Rufli, 1989c) and LC50 > 63 mg/L (Rufli, 1989d), based on mean measured concentrations.

Metabolite - available information

Four acute toxicity studies on Rainbow trout (Oncorhynchus mykiss) are available with the major degradation products (i.e. M4, M6 and M7). As the dossier has been prepared to address the test substance itself, these studies are not summarised as endpoint study records but are briefly discussed here. In the study with M4, the nominal test concentrations were 0.43, 0.94, 2.1, 4.5 and 10 mg/L (mean measured concentrations: 0.35, 0.78, 1.6, 1.7 and 1.8 mg/L, respectively). The 96-hour LC50 was determined to be 1.1 mg/L, based on mean measured concentration (Swarbrick & Shaillabeer 2002). In the study with M6, the nominal test concentrations were 0.43, 0.94, 2.07, 4.55 and 10 mg/L (mean measured concentrations: 0.10, 0.36, 1.05, 2.71 and 5.71 mg/L, respectively). The 96 -hour LC50 was calculated to be 0.37 mg/L (mean measured) (Grade, 1994). In the two studies with M7, the 96-hour LC50 was determined to be > 100 mg/L (nominal), in a limit test (Rufli, 1989), and > 124 mg/L based on mean measured concentration, with mean measured test concentrations of 16, 27, 46, 76 and 124 mg/L (nominal concentrations: 16, 26, 43, 72 and 120 mg/L) (Palmer et al. 2001).