3-iodo-2-propynyl butylcarbamate

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:

weight of evidence

Study period:

1991-12-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Protocol for Conducting a Flow-Through Acute Toxicity Test with Sheepshead Minnow (Cyprinodon variegatus) Following FIFRA Guideline 72-3

Version / remarks:

1991

Deviations:

no

Principles of method if other than guideline:

The data and report were produced and compiled in accordance with all pertinent EPA Good Laboratory Practice regulations (40 CFR, Part 160) with the following exceptions:
stability, characterization and verification of the test substance identity. Maintenance of records on the test substance is the responsibility of the test Sponsor. Routine water and food contaminant screening analyses for pesticides, PCBs and metals were conducted by Lancaster Laboratories, Lancaster, PA. These data were not collected in accordance with Good Laboratory Practice procedures. At the termination of the testing program, all remaining test material will be sent to the Study Sponsor. Maintenance of a sample of the test material is the responsibility of the Study Sponsor.

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 9102-6111

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature, in the dark

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Both replicate solutions of the high, middle and low treatment levels and the dilution water control were sampled and analyzed for the test item concentration once prior to the initiation of the definitive study. During the in-life phase of the definitive study, water samples were removed from both replicate test solutions of each treatment level and the controls on test days 0 and 4 for analysis of test item concentration
- Sampling method: Each exposure solution sample was collected from the approximate midpoint of the aquarium with a volumetric pipet.
- Sample storage conditions before analysis: Three Quality Control (QC) samples were prepared at each sampling interval and remained with the set of exposure solution samples throughout the analytical process. The QC samples were prepared in dilution water at test item concentrations which approximated the test concentration range.

Vehicle:

yes

Remarks:

Acetone

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A slightly cloudy (white-colored) 16.3 mg/mL stock solution was prepared by dissolving approximately 8.395 g of test material with acetone to volume in a 500 mL volumetric flask. A 0.4 mL/mL solvent stock solution was also prepared by diluting 100 mL of acetone with distilled water to volume in a 250 mL volumetric flask.
- Controls: vehicle control and dilution water control
- Chemical name of vehicle: Acetone
- Concentration of vehicle in test medium: The solvent control solutions contained a concentration of acetone which equaled the solvent in the highest test treatment level (0.092 mL/L).
- Evidence of undissolved material: Throughout the exposure period, undissolved test material was observed in the diluter system (e.g., mixing chamber, chemical cells, splitters), however, no visible sign of undissolved test material was observed in any of the exposure solutions.

Test organisms (species):

Cyprinodon variegatus

Details on test organisms:

TEST ORGANISM
- Common name: Sheepshead minnow
- Strain: #91A76
- Source: Aquatic Biosystems, Fort Collins, Colorado
- Length at study initiation: mean (range) total length: 31 (24 - 42) mm
- Weight at study initiation: mean (range) wet weight: 0.40 (0.21 - 0.81) g

ACCLIMATION
- Acclimation period: 14 d
- Acclimation conditions: same as test
- Type and amount of food during acclimation: commercially prepared flaked diet, ad libitum
- Feeding frequency during acclimation: daily, except the final 48 h before test initiation
- Health during acclimation: no mortality observed

FEEDING DURING TEST
Fish were not fed during the test

Sheepshead minnow is a recommended (EPA) species and a commonly used warm water fish in acute marine fish toxicity tests.

Test type:

flow-through

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

20-21 °C

pH:

7.7 - 7.8

Dissolved oxygen:

85-89 %

Salinity:

31 - 32 promille

Conductivity:

31000 - 36000 µmhos/cm

Nominal and measured concentrations:

Nominal: 1.5, 0.90, 0.54, 0.32 and 0.19 mg/L
Measured: 1.1, 0.54, 0.36, 0.23 and 0.14 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 19.5-L glass aquaria which measured 39 x 20 x 25 centimeters (cm) with a constant level overflow located at 14.5 cm from the bottom of the test aquaria
- Aeration: no
- Type of flow-through: constant flow serial diluter
- Renewal rate of test solution: 50 mL/min; meaning 6.5 volume replacements per aquarium every 24 h
- 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
- Biomass loading rate: At any given time during the exposure period, the maximum organism loading concentration was 0.056 g of biomass per liter of flowing test solution per day.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The dilution water was collected from the Cape Cod Canal, Bourne, Massachusetts with a pump (fiberglass reinforced thermoplastic housing) and a polyvinyl chloride (PVC) pipe and was then transported to the laboratory in a 3400 L fiberglass tank. In the laboratory, the seawater was passed through a series of polypropylene core filters (20- and 5-micron) and then recirculated within an epoxy-lined concrete reservoir prior to use. The filtered seawater was pumped to the laboratory under constant pressure through PVC pipe and a polypropylene heat exchanger system.
- Total organic carbon: Based on monthly analyses, the TOC concentration of the dilution water source was 1.9 mg/L for the month of October 1991.
- Pesticides: In accordance with EPA-GLP, routine analyses were also conducted on representative samples of the seawater for the presence of pesticides and PCBs. None of these compounds have been detected at concentrations that are considered toxic in any of the water samples analyzed, in agreement with US EPA and ASTM standard practices.
- Culture medium different from test medium: no
- Intervals of water quality measurement: Dissolved oxygen concentration, pH, temperature and salinity were measured once daily in each replicate solution of each treatment level and the controls throughout the exposure period.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours of light and 8 hours of darkness, sudden transitions from dark to light and vice versa were avoided
- Light intensity: 25 -50 footcandle (equivalent to approx. 269.1 - 538.2 lux)

EFFECT PARAMETERS MEASURED:
Biological observations of the exposed sheepshead minnow and observations of the physical characteristics of the test solutions (e.g., precipitate, film on solutions surface) were made at test initiation and at each subsequent 24-hour interval until test termination (96-hour). Effects for this study were based on death, defined as the lack of movement by the exposed organisms (i.e., absence of gill movement and reaction to gentle prodding). Mortalities were recorded and removed from each aquarium every 24 hours during the exposure.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.67
- Range finding study: yes
- Test concentrations: 1.5, 0.90, 0.54, 0.32 and 0.19 mg/L
- Results used to determine the conditions for the definitive study: Selection of test item concentrations for the 96-hour definitive flow-through toxicity test with sheepshead minnow was based on toxicology information developed at SLI through preliminary testing.

Reference substance (positive control):

no

Key result

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

> 1.1 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

0.75 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

0.49 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.41 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.14 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Other biological observations: Sublethal effects (e.g., lethargy, loss of equilibrium) were observed among all of the surviving fish exposed to the 0.54, 0.36 and 0.23 mg/L test concentrations
- Mortality of control: no
- Other adverse effects control: no
- Any observations that might cause a difference between measured and nominal values: The mean measured concentrations (day 0 and 4 analysis) averaged 68% of the nominal treatment levels. Throughout the pretest and definitive exposures, undissolved test material was observed in the diluter system (e.g., mixing chamber, chemical cells, splitters). No undissolved test material was observed in any of the exposure vessels throughout the exposure period. The presence of undissolved test material in the diluter system is believed to have had no significance on the results of this test.
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

not applicable

Validity criteria fulfilled:

yes

Conclusions:

Sheapshed minnow was exposed to the test item with nominal concentrations of 1.5, 0.90, 0.54, 0.32 and 0.19 mg/L under flow through conditions up to 96 h. Based on results obtained in this study, the test item is considered to be acutely toxic to fish.

Executive summary:

The purpose of this study was to estimate the acute toxicity (LC50) of the test item to sheepshead minnow (Cyprinodon variegatus) under flow-through conditions. The LC50 is defined as the concentration of test material estimated to cause mortality among 50% of the test population at the stated exposure interval. Twenty organisms (ten per replicate) were exposed in duplicate test vessels to five concentrations of the test item, a solvent (acetone, CAS 67-64-1) control and a dilution water control. During the test, nominal concentrations of 1.5, 0.90, 0.54, 0.32 and 0.19 mg/L were maintained by introducing approximately 6.5 aquarium volumes per day of newly prepared test solution via constant-flow serial diluter. Each replicate solution was sampled and analyzed for test item concentration on test days 0 (initiation) and 4 (termination) of the exposure period. Based on the results of these analyses, the mean measured exposure concentrations were defined as 1.1, 0.54, 0.36, 0.23 and 0.14 mg/L. Biological observations were made and recorded at test initiation and every 24 hours thereafter until the test was terminated. Throughout the exposure period, undissolved test material was observed in the diluter system (e.g., mixing chamber, chemical cells, splitters), however, no visible sign of undissolved test material was observed in any of the exposure solutions.

Following 72 hours of exposure, 100% mortality was observed among fish exposed to the highest mean measured concentration tested (1.1 mg/L). At test termination, mortalities of 95 and 20% were observed among fish exposed to the 0.54 and 0.36 mg/L test concentrations, respectively, while no mortality was observed among fish exposed to the remaining two concentrations tested (0.23 and 0.14 mg/L). Sublethal effects (e.g., lethargy, loss of equilibrium) were observed among all of the surviving fish exposed to the 0.54, 0.36 and 0.23 mg/L test concentrations. The No Observed Effect Concentration (NOEC) through 96-hours of exposure was established to be 0.14 mg/L. Based on criteria established by U.S. EPA (1985), the test item would be classified as highly toxic to sheepshead minnow.
Results:
LC50, 24 h = >1.1 mg/L
LC50, 48 h = 0.75 mg/L
LC50, 72 h = 0.49 mg/L
LC50, 96 h = 0.41 mg/L
NOAEC, 96h = 0.14 mg/L

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1990-06-27

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 72-1 (Fish Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: P8907-4914-P100

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 150, 90, 54, 32, 19 µg/L
- Sampling method: Each exposure solution sample was collected from the approximate midpoint of the aquarium with a volumetric pipet.
- Sample storage conditions before analysis: In addition, three quality control (QC) samples were prepared at each sampling interval and remained with the set of exposure solution samples through the analytical process. The QC samples were prepared in dilution water at test item concentrations which approximated the test concentration range.

Vehicle:

yes

Remarks:

acetone

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: On exposure day 0, a clear colorless stock solution of 2.04 mg/mL was prepared by diluting 0.522 grams (0.510 grams), weighed using an SP 182 balance, with acetone (CAS #67-64-1) to a total volume of 250 mL.
- Controls: vehicle control and dilution water control
- Chemical name of vehicle: acetone
- Concentration of vehicle in test medium: The solvent control solution contained the maximum amount of acetone present in any test concentration (0.074 mL/L).
- Evidence of undissolved material: Throughout the pretest and definitive exposure, no visible sign of precipitate or undissolved material was present in the test vessels or diluter apparatus.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Strain: SLI lot #90A6
- Source: Mount Lassen Trout Farms, a commercial supplier in California
- Age at study initiation: fish used during this study were all of the same year class
- Length at study initiation: mean (range): 41 (38 - 47) mm
- Weight at study initiation: mean (range): 0.66 (0.54 - 86) g

ACCLIMATION
- Acclimation period: 14 d
- Acclimation conditions: same as test
- Type and amount of food during acclimation: commercial pelleted food, ad libitum
- Feeding frequency during acclimation: daily, except during the 48-hours prior to initiation of the definitive study
- Health during acclimation: no mortality observed

FEEDING DURING TEST
The test fish were not fed during the exposure period.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

calcium carbonate (CaCOa) of 29 - 36 mg/L

Test temperature:

12 - 13 °C

pH:

7.0 - 7.2

Dissolved oxygen:

77 - 87%

Conductivity:

120 - 130 micromhos per centimeter (µmhos/cm)

Nominal and measured concentrations:

nominal: 150, 90, 54, 32 and 19 µg/L
definitive exposure levels: 120, 79, 49, 24 and 22 µg/L. Coefficients of variation for all mean measured concentrations averaged 20%.

Details on test conditions:

TEST SYSTEM
- Test vessel: Each glass test aquarium measured 39 x 20 x 25 centimeters (cm) with a 19.5 cm high standpipe which maintained a constant test water volume of 15 L
- Aeration: no
- Renewal rate of test solution: The diluter was constructed to deliver 4.1 L/hour of solution to each replicate test aquarium, providing approximately 6.5 volume replacements per aquarium every 24 hours.
- 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
- Biomass loading rate: The maximum organism loading concentration during the exposure period was 0.067 g of biomass per liter of flowing test solution per day.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Well water
- Total organic carbon: Based on monthly analyses, the TOC concentration of the dilution water was determined to be 0.593 ppm in February 1990
- Pesticides: No pesticide or PCB compounds have been detected in any of the water samples analyzed, in agreement with US EPA and ASTM guidelines
- Alkalinity: 20-22 mg/L CaCO3
- Culture medium different from test medium: no
- Intervals of water quality measurement: Dissolved oxygen concentration, temperature, and pH were measured daily in each replicate of each treatment level and the controls

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: photoperiod of 16 hours of light and 8 hours of darkness
- Light intensity: 70 - 100 footcandles (equivalent to approx. 753.5 - 1076.4 lux)

EFFECT PARAMETERS MEASURED:
Biological observations of the exposed rainbow trout were made at test initiation and at each subsequent 24-hour interval until termination of the test. Effects for this study were based on death, defined as the lack of movement by the expose organisms (i.e., absence of gili movement and reaction to gentle prodding). Mortalities were recorded and removed from each aquarium every 24 hours during the exposure.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.7
- Range finding study: yes
- Test concentrations: 150, 90, 54, 32, 19 µg/L

Reference substance (positive control):

no

Key result

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

> 120 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

97 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

83 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

67 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

49 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Mortality of control: no
- Other adverse effects control: no
- Any observations that might cause a difference between measured and nominal values: Throughout the pretest and definitive exposure, no visible sign of precipitate or undissolved material was present in the test vessels or diluter apparatus. Analysis of the exposure solutions resulted in measured concentrations which were consistent between replicate solutions and established the expected concentration range. Based on these analyses, the mean measured concentrations averaged 91% of the nominal treatment levels.
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

The mean measured concentrations tested (day 0 and 4 analysis) and the corresponding mortality data derived from the toxicity test were used to estimate the median lethal concentrations (LC50) and 95% confidence intervals at each 24-hour interval of the exposure period. The LC50 is defined as the concentration of the test material in dilution water lethal to 50% of the test animal population at the stated exposure interval. If at least one test concentration caused mortality of greater than or equal to 50% of the test population, then a computer program (Stephan, 1977,1982) was used to calculate the LC50 values and 95% confidence intervals. Three statistical methods were available in the computer program: moving average angle analysis, probit analysis, and nonlinear interpolation with 95% confidence intervals calculated by binomial probability. Moving average angle and probit analyses yield statistically sound results only if at least two concentrations produce a mortality of between 0 and 100% of the test organism population. The selection of reported LC50 values and 95% confidence intervals was based upon an examination of the data base and the results of the computer analysis. Selection criteria included the establishment of a concentration-effect relationship (mortality), the number of concentrations causing partial responses, and the span of responses bracketing the LC50 value. If two or more statistical methods produced acceptable results, then the method which yielded the smallest 95% confidence interval was selected. The No Observed Effect Concentration (NOEC), defined as the highest concentration tested at and below which there were no significant toxicant-related mortalities or physical and behavioral abnormalities (e.g., lethargy, loss of equilibrium, darkened pigmentation) was also determined.

Validity criteria fulfilled:

yes

Conclusions:

Rainbow trout was exposed to test item concenctrations of 150, 90, 54, 32 and 19 µg/L for 96 h under flow through conditions. Under the test conditions, the test item is considered to be acutely toxic to fish.

Executive summary:

The purpose of this study was to estimate the acute toxicity (LC50) of the test item to rainbow trout (Oncorhynchus mykiss) under flow-through conditions.The LC50 is defined as the concentration of test material estimated to cause mortality among 50% of a test population after the stated exposure interval.In duplicate test aquaria, twenty organisms were exposed to five concentrations of test item, a solvent control and a dilution water control. During the test nominal concentrations (based on active ingredient, AX) of 150, 90, 54, 32 and 19 µg/L were maintained by introducing approximately 6.5 aquarium volumes per day of newly prepared test solution via a constant flow serial diluter apparatus. Each replicate solution was sampled and analyzed for the test item concentration prior to test initiation and on days 0 and 4 of the exposure period. Based on the results of these analyses, the mean measured test concentrations were 120, 79, 49, 24 and 22 µg/L test item.Throughout the exposure period, test solutions were clear and contained no visible sign of undissolved material (e.g., precipitate, film on solution surface). Biological observations were made and recorded at test initiation and every 24 hours thereafter until the test was terminated.

Following 96 hours exposure, 100% mortality was observed in the highest treatment level (120 µg/L). During the same period, mortality of 70% was observed in the 79 µg/L treatment level. There was no mortality in the remaining concentrations (49, 24 and 22 µg/L). One fish at the 49 and 24 µg/L treatment levels exhibited lethargic behavior. The No Observed Effect Concentration (NOEC) through 96 hours was 49 µg/L test item. Based on criteria established by U.S. EPA (1985), the test item would be classified as very highly toxic to rainbow trout.

Results:

LC50, 24 h = >120 µg/L
LC50, 48 h = 97 µg/L
LC50, 72 h = 83 µg/L
LC50, 96 h = 67 µg/L
LOAEC, 96 h = 49 µg/L

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1990-06-27

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 72-1 (Fish Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: P8907-4914-P100

Analytical monitoring:

yes

Details on sampling:

- Concentrations: nominal 500, 300, 180, 110 and 65 µg/L

Vehicle:

yes

Remarks:

acetone

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: On exposure day -3, a clear colorless stock solution of 6.8 mg/mL was prepared by diluting 3.48 grams (3.40 grams active ingredient), weighed using an SP 182 balance, with acetone (CAS #67-64-1) to a total volume of 500 mL
- Controls: vehicle control and dilution water control
- Chemical name of vehicle: Acetone
- Concentration of vehicle in test medium: The solvent control solution contained the maximum amount of acetone present in any test concentration (0.074 mL/L)
- Evidence of undissolved material: Throughout the exposure period, test solutions were clear and contained no visible sign of undissolved material (e.g. precipitate, film on the solution surface).

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

TEST ORGANISM
- Common name: bluegill sunfish
- Strain: SLI lot #89A50b
- Source: Bybrook Bass Hatchery, a commercial supplier in Connecticut
- Age at study initiation: The bluegill sunfish used during this study were all of the same year class
- Length at study initiation mean (range): 42 (33 - 48) mm
- Weight at study initiation mean (range): 1.0 (0.26 - 1.63) g

ACCLIMATION
- Acclimation period: 14 d
- Acclimation conditions: same as test
- Type and amount of food during acclimation: all fish were fed a commercial pelleted food, ad libitum
- Feeding frequency during acclimation: daily, except during the 48-hours prior to initiation of the definitive test
- Health during acclimation: no mortality observed

FEEDING DURING TEST
Fish were not fed during the study.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

20-22 mg/L CaCO3

Test temperature:

20 - 23 °C

pH:

7.1-7.3

Conductivity:

130-140 umhos/cm

Nominal and measured concentrations:

nominal concentrations: 500, 300, 180, 110 and 65 µg/L
mean measured test concentrations: 320, 210, 140, 77 and 56 µg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: each glass test aquarium measured 39 x 20 x 25 centimeters (cm) with a 19.5 cm high standpipe which maintained a constant test water volume of 15 L
- Aeration: no
- Type of flow-through: proportional diluter
- Renewal rate of test solution: 4.1 L/hour; approx. 6.5 volume replacements per aquarium every 24 hours
- 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
- Biomass loading rate: the maximum organism loading concentration during the exposure period was 0.10 g of biomass per liter of flowing test solution per day

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: well water
- Total organic carbon: based on monthly analyses, the TOC concentration of the dilution water was determined to be 0.593 ppm in February 1990
- Pesticides: In conformance with EPA-GLP, routine analyses were also conducted on representative samples from the dilution water source for the presence of pesticides and PCB's. None of the compounds have been detected in any of the water samples analyzed, in agreement with US EPA and ASTM guidelines
- Alkalinity: 25 - 31 mg/L
- Culture medium different from test medium: no
- Intervals of water quality measurement: observations of the physical characteristics of the test solutions (e.g., precipitate, film on solution's surface) were made at test initiation and at each subsequent 24-hour interval until termination of the test

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours of light and 8 hours of darkness
- Light intensity: 70 -110 footcandles (equivalent to approx. 753.5 - 1184.0 lux)

EFFECT PARAMETERS MEASURED:
Biological observations of the exposed bluegill sunfish were made at test initiation and at each subsequent 24-hour interval until termination of the test. Effects for this study were based on death, defined as the lack of movement by the exposed organisms (i.e., absence of gill movement and reaction to gentle prodding). Mortalities were recorded and removed from each aquarium every 24 hours during the exposure.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.6
- Range finding study: yes
- Test concentrations: 500, 300, 180,110 and 65 µg/L

Key result

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

> 320 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

230 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

230 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

230 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

140 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Mortality of control: no
- Other adverse effects control: no
- Any observations that might cause a difference between measured and nominal values: Throughout the exposure period, test solutions were clear and contained no visible sign of undissolved material (e.g. precipitate, film on the solution surface).
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

The mean measured concentrations tested (day 0 and 4 analysis) and the corresponding mortality data derived from the toxicity test were used to estimate the median lethal concentrations (LC50) and 95% confidence intervals at each 24-hour interval of the exposure period. The LC50 is defined as the concentration of the test material in dilution water lethal to 50% of the test animal population at the stated exposure interval. If at least one test concentration caused mortality of greater than or equal to 50% of the test population, then a computer program (Stephan, 1977,1982) was used to calculate the LC50 values and 95% confidence intervals. Three statistical methods were available in the computer program: moving average angle analysis, probit analysis, and nonlinear interpolation with 95% confidence intervals calculated by binomial probability. Moving average angle and probit analyses yield statistically sound results only if at least two concentrations produce a mortality of between 0 and 100% of the test organism population. The selection of reported LC50 values and 95% confidence intervals was based upon an examination of the data base and the results of the computer analysis. Selection criteria included the establishment of a concentration-effect relationship (mortality), the number of concentrations causing partial responses, and the span of responses bracketing the LC50 value. If two or more statistical methods produced acceptable results, then the method which yielded the smallest 95% confidence interval was selected. The No Observed Effect Concentration (NOEC), defined as the highest concentration tested at and below which there were no significant toxicant-related mortalities or physical and behavioral abnormalities (e.g., lethargy, loss of equilibrium, darkened pigmentation) was also determined.

Validity criteria fulfilled:

yes

Conclusions:

Bluegill sunfish was exposed to the test item nominal with concentrations of 500, 300, 180, 110 and 65 µg/L for 96 h under flow through conditions. Under the test conditions, the test item is considered to be acutely toxic to fish.

Executive summary:

The purpose of this study was to estimate the acute toxicity (LC50) of the test item to bluegill sunfish (Lepomis macrochirus) under flow-through conditions. The LC50 is defined as the concentration of test material estimated to cause mortality among 50% of a test population after the stated exposure interval. In duplicate test aquaria, twenty organisms were exposed to five concentrations of test item, a solvent control and a dilution water control. During the test nominal concentrations (based on active ingredient, A.l.) of 500, 300, 180, 110 and 65 µg/L were maintained by introducing approximately 6.5 aquarium volumes per day of newly prepared test solution via a constant flow serial diluter apparatus. Each replicate solution was sampled and analyzed for the test item concentration prior to test initiation and on days 0 and 4 of the exposure period. Based on the results of these analyses, the mean measured test concentrations were 320, 210, 140, 77 and 56 µg/L. Throughout the exposure period, test solutions were clear and contained no visible sign of undissolved material (e.g. precipitate, film on the solution surface). Biological observations were made and recorded at test initiation and every 24 hours thereafter until the test was terminated.

Following 96 hours exposure, 100% mortality was observed in the highest treatment level (320 µg/L). During the same period, mortality of 35% was observed in the 210 µg/L treatment level. All surviving fish (96 hours) at the 210 µg/L treatment had darkened pigmentation and exhibited lethargic behavior. There was no mortality or adverse effects observed among organisms in the remaining concentrations (140, 77, and 56 µg/L).

The No Observed Effect Concentration (NOEC) through 96 hours was 140 µg/L. Based on criteria established by U.S. EPA (1985), the test item would be classified as highly toxic to bluegill sunfish.

LC50, 24 h > 320 µg/L
LC50, 48 h = 230 µg/L
LC50, 72 h = 230 µg/L
LC50, 96 h = 230 µg/L
NOAEC, 96 h = 140 µg/L

Description of key information

Sheapshed minnow was exposed to the test item with nominal concentrations of 1.5, 0.90, 0.54, 0.32 and 0.19 mg/L under flow through conditions up to 96 h. Based on results obtained in this study, the test item is considered to be acutely toxic to fish, LC50 was determined to be 0.41 mg/L.

Rainbow trout was exposed to test item nominal concenctrations of 150, 90, 54, 32 and 19 µg/L for 96 h under flow through conditions. Under the test conditions, the test item is considered to be acutely toxic to fish, LC50 was determined to be 67 µg/L and NOEC was determined to be 49 µg/L.

Bluegill sunfish was exposed to the test item with nominal concentrations of 500, 300, 180, 110 and 65 µg/L for 96 h under flow through conditions. Under the test conditions, the test item is considered to be acutely toxic to fish, LC50 was determined to be 230 µg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.067 mg/L

Marine water fish

Marine water fish

Effect concentration:

0.41 mg/L

Additional information

Acute toxicity to Sheepshead minnow

The purpose of this study was to estimate the acute toxicity (LC50) of the test item to sheepshead minnow (Cyprinodon variegatus) under flow-through conditions. The LC50 is defined as the concentration of test material estimated to cause mortality among 50% of the test population at the stated exposure interval. Twenty organisms (ten per replicate) were exposed in duplicate test vessels to five concentrations of the test item, a solvent (acetone, CAS 67-64-1) control and a dilution water control. During the test, nominal concentrations of 1.5, 0.90, 0.54, 0.32 and 0.19 mg/L were maintained by introducing approximately 6.5 aquarium volumes per day of newly prepared test solution via constant-flow serial diluter. Each replicate solution was sampled and analyzed for test item concentration on test days 0 (initiation) and 4 (termination) of the exposure period. Based on the results of these analyses, the mean measured exposure concentrations were defined as 1.1, 0.54, 0.36, 0.23 and 0.14 mg/L. Biological observations were made and recorded at test initiation and every 24 hours thereafter until the test was terminated. Throughout the exposure period, undissolved test material was observed in the diluter system (e.g., mixing chamber, chemical cells, splitters), however, no visible sign of undissolved test material was observed in any of the exposure solutions.

Following 72 hours of exposure, 100% mortality was observed among fish exposed to the highest mean measured concentration tested (1.1 mg/L). At test termination, mortalities of 95 and 20% were observed among fish exposed to the 0.54 and 0.36 mg/L test concentrations, respectively, while no mortality was observed among fish exposed to the remaining two concentrations tested (0.23 and 0.14 mg/L). Sublethal effects (e.g., lethargy, loss of equilibrium) were observed among all of the surviving fish exposed to the 0.54, 0.36 and 0.23 mg/L test concentrations. The No Observed Effect Concentration (NOEC) through 96-hours of exposure was established to be 0.14 mg/L. Based on criteria established by U.S. EPA (1985), the test item would be classified as highly toxic to sheepshead minnow.
Results:
LC50, 24 h = >1.1 mg/L
LC50, 48 h = 0.75 mg/L
LC50, 72 h = 0.49 mg/L
LC50, 96 h = 0.41 mg/L
NOAEC, 96h = 0.14 mg/L

Acute toxicity to Rainbow trout

The purpose of this study was to estimate the acute toxicity (LC50) of the test item to rainbow trout (Oncorhynchus mykiss) under flow-through conditions.The LC50 is defined as the concentration of test material estimated to cause mortality among 50% of a test population after the stated exposure interval.In duplicate test aquaria, twenty organisms were exposed to five concentrations of test item, a solvent control and a dilution water control. During the test nominal concentrations (based on active ingredient, AX) of 150, 90, 54, 32 and 19 µg/L were maintained by introducing approximately 6.5 aquarium volumes per day of newly prepared test solution via a constant flow serial diluter apparatus. Each replicate solution was sampled and analyzed for the test item concentration prior to test initiation and on days 0 and 4 of the exposure period. Based on the results of these analyses, the mean measured test concentrations were 120, 79, 49, 24 and 22 µg/L test item.Throughout the exposure period, test solutions were clear and contained no visible sign of undissolved material (e.g., precipitate, film on solution surface). Biological observations were made and recorded at test initiation and every 24 hours thereafter until the test was terminated.

Following 96 hours exposure, 100% mortality was observed in the highest treatment level (120 µg/L). During the same period, mortality of 70% was observed in the 79 µg/L treatment level. There was no mortality in the remaining concentrations (49, 24 and 22 µg/L). One fish at the 49 and 24 µg/L treatment levels exhibited lethargic behavior. The No Observed Effect Concentration (NOEC) through 96 hours was 49 µg/L test item. Based on criteria established by U.S. EPA (1985), the test item would be classified as very highly toxic to rainbow trout.

Results:

LC50, 24 h = >120 µg/L
LC50, 48 h = 97 µg/L
LC50, 72 h = 83 µg/L
LC50, 96 h = 67 µg/L
LOAEC, 96 h = 49 µg/L

Acute toxicity to Bluegill sunfish

The purpose of this study was to estimate the acute toxicity (LC50) of the test item to bluegill sunfish (Lepomis macrochirus) under flow-through conditions. The LC50 is defined as the concentration of test material estimated to cause mortality among 50% of a test population after the stated exposure interval. In duplicate test aquaria, twenty organisms were exposed to five concentrations of test item, a solvent control and a dilution water control. During the test nominal concentrations (based on active ingredient, A.l.) of 500, 300, 180, 110 and 65 µg/L were maintained by introducing approximately 6.5 aquarium volumes per day of newly prepared test solution via a constant flow serial diluter apparatus. Each replicate solution was sampled and analyzed for the test item concentration prior to test initiation and on days 0 and 4 of the exposure period. Based on the results of these analyses, the mean measured test concentrations were 320, 210, 140, 77 and 56 µg/L. Throughout the exposure period, test solutions were clear and contained no visible sign of undissolved material (e.g. precipitate, film on the solution surface). Biological observations were made and recorded at test initiation and every 24 hours thereafter until the test was terminated. Following 96 hours exposure, 100% mortality was observed in the highest treatment level (320 µg/L). During the same period, mortality of 35% was observed in the 210 µg/L treatment level. All surviving fish (96 hours) at the 210 µg/L treatment had darkened pigmentation and exhibited lethargic behavior. There was no mortality or adverse effects observed among organisms in the remaining concentrations (140, 77, and 56 µg/L).

The No Observed Effect Concentration (NOEC) through 96 hours was 140 µg/L. Based on criteria established by U.S. EPA (1985), the test item would be classified as highly toxic to bluegill sunfish.

Results:

LC50, 24 h > 320 µg/L
LC50, 48 h = 230 µg/L
LC50, 72 h = 230 µg/L
LC50, 96 h = 230 µg/L
NOAEC, 96 h = 140 µg/L