5,7-dichloro-4-(4-fluorophenoxy)quinoline;quinoxyfen (ISO)

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:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

TSN 100010
Purity: 99.0%

Analytical monitoring:

yes

Details on sampling:

Discrepancies were observed between nominal and analytical concentrations of dissolved XDE-795 in aqueous solution. These differences were attributed to the limited water solubility of XDE-795 mg/L. The measured recovery of the dilutor feedstock solution in dimethylformamide (DMF) averaged 101%.

Vehicle:

yes

Remarks:

dimethylformamide

Test organisms (species):

Lepomis macrochirus

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Nominal and measured concentrations:

Nominal: 0.08, 0.13, 0.22, 0.36, 0.60, and 1.0 mg/L, with solvent and water controls
Measured: 0.038, 0.060, 0.094, 0.138, 0.197, and 0.284 mg/L, with solvent and water controls

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.28 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: the LC50 value is more than twice the aqueous solubility of the material

Details on results:

Lethal and sublethal effects, such as loss of equilibrium, lethargy, and abdominal bloating, were not observed during the conduct of this study.

Validity criteria fulfilled:

yes

Conclusions:

96-hr LC50 (bluegill sunfish) > 0.28 mg/L (the highest dose tested and twice the aqueous solubility of the material)

Executive summary:

The test substance was tested for acute toxicity to the bluegill, Lepomis macrochirus Rafinesque. The study was designed as a 96-hour flow-through test with replicate groups of ten bluegill each exposed to analyzed concentrations of 0.038, 0.060, 0.094, 0.138, 0.197 and 0.284 mg XDE-795 a.i. per liter, and solvent and laboratory water controls. The test was conducted according to OECD guideline 203. A number of these exposure concentrations were deliberately in excess of the aqueous solubility of XDE-795, approximately 0.116 mg/L. The 72-hour and 96-hour LC50s for bluegill were above the measured concentration of 0.28 mg/L. There were no sub-lethal effects noted during the conduct of this study. The no-observed-effect concentration (NOEC) was a measured concentration of 0.28 mg/L (nominal concentration of 1.0 mg/L).

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

XDE-795 Technical
Lot #RMM 2060
Purity: 98.1 %

Analytical monitoring:

yes

Details on sampling:

The measured concentrations of XDE- 795 Technical in test dilution water were determined at 0, 24, 72, and 96 hours of the toxicity test. The 0- and 72-hour samples were collected immediately after preparation (new solutions); the 24- and 96-hour samples were collected approximately 24 hours after sample preparation (old solutions). Control and XDE-795 Technical-fortified samples were also determined at each sample period. Concentrations of XDE-795 Technical were measured by HPLC.

Vehicle:

yes

Details on test solutions:

The definitive test concentrations were obtained by transferring appropriate aliquots of working standards directly to the test chambers. A parent standard at a concentration of 8000 mg/L was prepared by weighing 400 mg active ingredient (408 mg total product) into a 50-mL volumetric flask and bringing the flask to volume with acetone (Baxter lot #BK159). The standard was diluted in acetone to obtain working standards with nominal concentrations of 500, 1000, 2000, 4000, and 8000 mg/L. The dilution water was stirred with a glass stir rod, the aliquot of dosing stock was added to the vortex created by stirring and the test solution was again stirred. The vehicle blank chambers each received 1.5 mL of acetone which was equivalent to the amount of vehicle used in the exposure chambers.

New solutions were prepared each day and the fish were transferred from the old to the new solutions.

Test organisms (species):

Cyprinus carpio

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

22.6 - 24.0°C

pH:

7.7 to 8.3

Dissolved oxygen:

Dissolved oxygen ranged from 4.5 mg/L (55% of saturation at 23°C) to 8.3 mg/L (101 % of saturation at 23 °C). Although the dissolved oxygen decreased to less than 60 % saturation in several chambers, the solutions were not aerated since new solutions were prepared every 24 hours. Dissolved oxygen values < 60% saturation were observed only in the vehicle blank, 0.044, and 0.067 mg/L old solutions. Since the 0.044 and 0.067 mg/L concentrations showed no mortality or abnormal effects, this decrease in dissolved oxygen did not adversely affect the results of the study. One fish died in the vehicle blank chamber at 72 hours but all other fish in this concentration were normal.

Nominal and measured concentrations:

Nominal: 0.050,0.10, 0.20, 0.40, and 0.80 mg/L
Measured: 0.044, 0.067, 0.16, 0.32, and 0.57 mg/L

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.41 mg/L

Validity criteria fulfilled:

yes

Conclusions:

96-hr LC50 (common carp, Cyprinus carpio) = 0.41 mg/L

Executive summary:

The acute static renewal toxicity of XDE-795 Technical to common carp (Cyprinus carpio) was assessed using the methods outlined by OECD-203. The study was conducted with duplicate nominal test concentrations of 0.050,0.10, 0.20, 0.40, and 0.80 mg/L. Duplicate control and vehicle blank chambers were included. The overall mean measured concentrations achieved in the study were 0.044, 0.067, 0.16, 0.32, and 0.57 mg/L. Five common carp (Cyprinus carpio) were placed in each replicate chamber for a total of 10 fish per concentration and control. The fish were exposed for 96 hours at 23 ± 2°C.

All fish in the control, vehicle blank, 0.044-, and 0.067-mg/L mean measured concentrations were normal throughout the test, with the exception of one mortality at 72 hours in the vehicle blank A replicate. Abnormal effects of mortality, fish on bottom of the test chamber, dark discoloration, loss of equilibrium and/or quiescence were observed in the 0.16-, 0.32-, and 0.57-mg/L test concentrations. Cumulative mortality at 96 hours was 0, 10, 0, 0, 0, 40, and 70% for the control, vehicle blank, 0.044-, 0.067-, 0.16-, 0.32-, and 0.57-mg/L mean measured test concentrations, respectively. All toxicity results were based on the mean measured concentrations of XDE-795 Technical. The 96-hour LC50 was 0.41 mg/L with 95 % confidence limits of 0.30 and 0.63 mg/L. The slope of the 96-hour dose response line was 5.2. The 96-hour NOEC was 0.067 mg/L.

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: U.S. EPA FIFRA 72-3 (a)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Quinoxyfen (XDE-795) Technical
T.R. Wilbury sample number 1289
TSN 100097
Purity 97.4%

Analytical monitoring:

yes

Details on sampling:

- Nominal concentrations: 0 (control), 26, 44, 72, 120, 200 µg/L
- Sampling method: analytical determination performed on samples from each replicate test vessel of each concentration at the beginning and end of the test

Vehicle:

yes

Remarks:

Natural seawater adjusted to a salinity of 11 to 16 parts per thousand (ppt) with deionized water

Details on test solutions:

A stock solution with a nominal concentration of 2,000 mg/L was prepared by bringing 1.0265 g of test substance to a total volume of 500 mL with dimethylformamide. Appropriate amounts of the stock solution were added directly to dilution water by a proportional diluter (0.30 mL added to 3,000 mL of dilution water to yield a secondary stock solution with a nominal concentration of 200 ~µg/L). Nominal concentrations of Quinoxyfen (XDE-795) Technical were: 0 ~µg/L (control and solvent control), 26, 44, 72, 120, and 200 ~µg/L. The highest tested concentration was approximately twice the reported test substance water solubility and approximately equal to the test substance solubility determined during the analytical method validation using samples prepared in dilution water and dimethylformamide as a solvent.

Test organisms (species):

Cyprinodon variegatus

Details on test organisms:

TEST ORGANISM
- Common name: sheepshead minnows
- Source: Aquatic BioSystems, Inc., Fort Collins, Colorado

ACCLIMATION
- Acclimation period: at least 14 days
- Acclimation conditions: maintained under flow-through conditions in a polyethylene tank containing approximately 220 liters of dilution water
- Type and amount of food during acclimation: dry commercial food (Tetra Min® Staple Food, Lot # TM08)
- Feeding frequency during acclimation: daily, except for the 48 hour period prior to the start of the definitive toxicity test.
- Health during acclimation (any mortality observed): 0 mortality

FEEDING DURING TEST
Not fed during the test

Test type:

flow-through

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

Calcium: 0.044 mg/L
Magnesium: 0.40 mg/L

Test temperature:

21.6 to 22.4°C

pH:

7.8 to 8.0

Dissolved oxygen:

6.7 to 7.7 mg/L

Salinity:

15 to 16 ppt

Nominal and measured concentrations:

Nominal: 0 µg/L (control and solvent control),26, 44, 72, 120, and 200 µg/L
Measured: ND (none detected at or above the limit of quantitation of 0.908 µg/L; control and solvent control), 24.6, 38.5, 61.7,92.0, and 168 µg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 20-liter glass aquaria that contained 15 liters of test solution with water depth approximately 18 cm
- Aeration: not required to maintain dissolved oxygen concentrations above acceptable levels
- Type of flow-through: intermittent flow proportional diluter
- 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: carbon filtered, natural seawater collected at T.R. Wilbury Laboratories in Marblehead, Massachusetts and adjusted to a salinity of 11 to 16 parts per thousand with carbon filtered deionized water. This water was stored in polyethylene tanks where it was aerated and recirculated through particle filters, activated carbon, and an ultraviolet sterilizer.
- Total organic carbon: 2.4 mg/L
- Metals: Boron 4.99 mg/L, Calcium 393 mg/L, Magnesium 982 mg/L, Potassium 378 mg/L, Sodium 9,900 mg/L
- Chloride: 18,300 mg/L

OTHER TEST CONDITIONS
- Photoperiod: 16- hour light/8- hour dark
- Light intensity: ~ 23 foot-candles

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 168 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Highest concentration tested and the approximate water solubility limit; no mortality

Remarks:

LC50 was for median lethal concentration

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

> 168 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Highest concentration tested and the approximate water solubility limit; no mortality

Remarks:

LC50 was for median lethal concentration

Details on results:

No sublethal effects
No mortality of control

Results with reference substance (positive control):

No mortality, no sublethal effects at all tested concentrations

Reported statistics and error estimates:

Results could not be interpreted by standard statistical techniques due to greater than 50% survival at all tested concentrations.

Validity criteria fulfilled:

yes

Conclusions:

96-Hour LC50 (sheepshead minnow): >168 µg/L (Mortality) (highest concentration tested)
96-Hour NOEC (sheepshead minnow): > 168 µg/L (Mortality) (highest concentration tested)

Executive summary:

The acute toxicity of Quinoxyfen (XDE-795) Technical to the sheepshead minnow,Cyprinodon variegatuswas performed under flow-through conditions with five concentrations of test substance, a dilution water control, and a solvent control (0.10 mL/L dimethylformamide) at a mean temperature of 22.0 °C. The dilution water was natural seawater collected at T.R. Wilbury Laboratories in Marblehead, Massachusetts, and adjusted to a salinity of 11 to 16 ppt with deionized water. Juvenile sheepshead minnows used in the test were acclimated to test conditions for at least 14 days prior to the start of the definitive toxicity test. All organisms were in good condition at the beginning of the study. Nominal concentrations of Quinoxyfen (XDE-795) Technical were: 0µg/L (control and solvent control), 26, 44, 72, 120, and 200µg/L. Mean measured concentrations of Quinoxyfen (XDE-795) were: ND (none detected at or above the limit of quantitation of 0.908µg/L; control and solvent control), 24.6, 38.5, 61.7, 92.0, and 168µg/L. Test solution samples were filtered prior to analysis. Mean measured concentrations were used for all calculations. Exposure of the sheepshead minnow,Cyprinodon variegatus,to Quinoxyfen (XDE-795) resulted in a 96-hour median lethal concentration (LC50) greater than 168µg/L, the highest tested concentration and the approximate water solubility of the test substance. The 96-hour no-observed effect concentration (NOEC) was 168µg/L Quinoxyfen (XDE-795).

Description of key information

96 -hour LC₅₀ (Rainbow trout): 0.27 mg./L; OECD 203; Reliability = 1

96 -hour LC₅₀ (Common carp): 0.42 mg/L; OECD 203; Reliability = 1

96 -hour LC₅₀ (Bluegill sunfish): > 0.28 mg/L (highest dose tested and twice the aqueous solubility of the material); OECD 203; Reliability = 1

96 -hour LC₅₀ (Sheepshead minnow): > 168 µg/L (highest concentration tested and approximate water solubility); FIFRA 72-3 (a); Reliability = 1

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.27 mg/L

Marine water fish

Marine water fish

Effect concentration:

168 µg/L

Additional information

The test substance was tested in 3 freshwater species and one saltwater species. Acute 96 -hour LC₅₀ values in freshwater species ranged from 0.27 mg/L to 0.42 mg/L in rainbow trout and common carp respectively.  In the saltwater species, the acute 96-hour LC₅₀ value was > 168 µg/L in the sheepshead minnow. The water solubility of the test substance is reported as 0.11 mg/L (or 110 µg/L). In two studies, there were no acute toxicity effects at concentrations up to the limit of aqueous solubility. In the other two studies, the LC₅₀ values reported are above the limits of aqueous solubility; however, the most sensitive acute 96h LC₅₀ for both freshwater and saltwater fish is less than 1 mg/L.