3-anilino-5-methyl-5-(4-phenoxyphenyl)-1,3-oxazolidine-2,4-dione;famoxadone (ISO)

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-term toxicity to aquatic invertebrates

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:

EPA OPP 72-4 (Fish Early Life-Stage and Aquatic Invertebrate Life-Cycle Studies)

Version / remarks:

1988

GLP compliance:

yes

Specific details on test material used for the study:

Purity: 97.8%
Batch: DPX-JE874-221

Analytical monitoring:

yes

Vehicle:

yes

Remarks:

Water and dimethylformamide (DMF) controls were used

Test organisms (species):

other aquatic crustacea: Mysidopsis bahia

Test type:

flow-through

Water media type:

saltwater

Remarks:

natural seawater collected from the Atlantic Ocean at T.R. Wilbury Laboratories in Marblehead，Massachusetts and adjusted to a salinity of 15-17 ppt

Total exposure duration:

28 d

Test temperature:

23.5 - 25.8°C

pH:

6.9 to 7.2

Dissolved oxygen:

5.6 - 7.9 mg/L

Salinity:

15 - 17 ppt

Nominal and measured concentrations:

Nominal: 1.0, 2.1，4.0，8Д and 16 µg/L.
Measured: 0.830，1.72, 3.69, 7.05, and 12.9 µg/L

Details on test conditions:

Sixty mysids were randomly selected and distributed to two replicate test vessels per concentration. Within each test vessel the 30 mysids were evenly subdivided into 2 retention chambers. When the sex of mysids could be determined (day 15 of the exposure) mysids within each vessel were rearranged so that a single male and female pair was placed in up to each of 10 chambers.

From the test initiation through sexual differentiation, the retention chambers consisted of an approximately 9 cm diameter glass petri dishes to which an approximately 13 cm high collar of Nitex® screen was attached by silicone adhesive. On day 15, the first day that mysids could be sexually differentiated, up to ten pairs of mysids were transferred to individual retention chambers which consisted of glass petri dishes to which a collar of Nitex® screen was attached by silicone adhesive (6 cm diameter x 12 cm high).

The test was performed in loosely covered, 20-liter glass aquaria (20 cm in width, approximately 40 cm in length, and 25 cm in height) that contained up to 8 liters of test solution. The test vessels were equipped with self starting siphons to insure adequate flow of test media to the mysids (test media depth ranged from 4 to 10 cm). Test vessels were randomly arranged in a water bath during the 28 day test (a random numbers table was used to select the location of each vessel). Test vessels were cleaned on days 3, 10, and 17.

The number of surviving organisms and the occurrence of sublethal effects on behavior or appearance (loss of equilibrium, erratic swimming, loss of reflex, excitability, discoloration, or change in behavior) were determined visually and recorded initially and at 24 hour intervals. Dead test organisms were removed when first observed. Beginning on day 15 of the exposure the mysids were categorized by sex. Female mysids were defined as those mysids with visible brood pouches. Offspring were counted and removed every day after day 17, the first day that young were present. At the termination of the test the total length of each surviving first generation mysid was determined with a Manostat caliper. Mysids were then rinsed with deionized water, blotted paper towels, and individually weighed. After length and wet weight determination, the mysids were placed in an oven adjusted to 60 to 63°C for 72 hours, transferred to a desiccator at room temperature for more than 1 day, and weighed.

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

0.83 µg/L

Duration:

28 d

Dose descriptor:

LOEC

Effect conc.:

1.72 µg/L

Basis for effect:

other: survival of the first generation

Duration:

28 d

Dose descriptor:

other: MATC

Effect conc.:

1.19 µg/L

Duration:

28 d

Dose descriptor:

EC50

Effect conc.:

2.98 µg/L

Details on results:

Control and solvent control survival at the end of the test was at least 87% in each replicate. Offspring production averaged 6.6 young per female in the control and 6.4 young per female in the solvent control. Mysids exhibiting lethargy and erratic swimming were observed on days 2 and 3 in test vessels with a mean measured concentration of 7.05 µg/L. These mysids did not survive to the end of the test and no other sublethal effects (other than growth and reproductive effects) were noted during the test.

The 7-day EC50 was 4.53 µg/L with 95% confidence limits of 3.69 to 7.05 µg/L and the slope of the /-day concentration-response curve was 8.8 with 95% confidence limits of-13 to 31. The 14-day EC50 was 3.55 µg/L with 95% confidence limits of 1.72 to 7.05 µg/L and the slope of the 14-day concentration-response curve was 4.3 with 95% confidence limits of -1.3 to 10. The 21-day EC50 was 3.18 µg/L with 95% confidence limits of 1.72 to 7.05 µg/L and the slope of the 21-day concentration-response curve was 3.6 with 95% confidence limits of-1.3 to 6.0. The 28-day EC50 was 2.98 µg/L with 95% confidence limits of 1.72 to 7.05 µg/L and the slope of the 28-day concentration-response curve was 3.3 with 95% confidence limits of 1.0 to 5.5.

The most sensitive measure of toxicity determined by statistical analysis of survival, growth, and reproduction data was the survival of first generation mysids after 28 days of exposure. Exposure of mysids to Famoxadone Technical resulted in a LOEC of 1.72 µg/L, a NOEC of 0.830 µg/L, and a MATC of 1.19 µg/L.

Validity criteria fulfilled:

yes

Conclusions:

The most sensitive measure of toxicity determined by statistical analysis of survival, growth, and reproduction data was the survival of first generation mysids after 28 days of exposure. Exposure of mysids to Famoxadone Technical resulted in a LOEC of 1.72 µg/L, a NOEC of 0.830 µg/L, and a MATC of 1.19 µg/L.

Executive summary:

The chronic toxicity of Famoxadone Technical to the mysid, Mysidopsis bahia, was determined via EPA guideline 72-4. The test was performed under flow-through, unaerated conditions with five concentrations of test substance, a solvent control (0.10 mL/L dimethylformamide), and a dilution water control at 25 ± 2°C. The dilution water was natural seawater collected from the Atlantic Ocean in Marblehead, Massachusetts, and diluted to a salinity of 15 to 17 parts per thousand with deionized water. The dilution water was adjusted to a pH of approximately 7.0 with 5% hydrochloric acid to increase the stability of the test substance in water. Nominal concentrations of Famoxadone Technical were 0 µg/L (control and solvent control), 1.0, 2.1, 4.0, 8.0 and 16 µg/L. Mean measured concentrations of Famoxadone were ND (not detected at or above the limit of quantitation of 0.324 (µg/L; control and solvent control), 0.830, 1.72, 3.69, 7.05, and 12.9 fig/L, and concentrations were stable throughout the test. Mean measured concentrations were used for the calculations of the no observed effect concentration (NOEC), lowest observed effect concentration (LOEC), and maximum acceptable toxicant concentration (MATC). Juvenile mysids used in the test were obtained from an in-house culture (the original culture was obtained from Aquatic BioSystems, Inc., Fort Collins, Colorado). They were less than 24 hours old ana m good condition at the beginning of the study.

 

Exposure of mysids to Famoxadone Technical resulted m a LOEC of 1.72 µg/L, a NOEC of 0.830 µg/L, and a MATC of 1.19 µg/L, when treatment data were compared to pooled control and solvent control data. The most sensitive determined by statistical analysis of survival, growth, and reproduction data was the survival of first generation mysids after 28 days of exposure. Other measured biological parameters were the number of young per surviving female, the total length of surviving first generation mysids, sublethal effects, the dry weight of surviving first generation mysids, and the wet weight of surviving first generation mysids.

Reference 2

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11-17-94 - 12-8-94

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: OECD 202

Version / remarks:

1984

Qualifier:

according to guideline

Guideline:

other: EPA 72-4

GLP compliance:

yes

Specific details on test material used for the study:

Purity: 97.4%
Batch: DPX-JE874-221

Analytical monitoring:

yes

Details on sampling:

- Sampling method: Four replicates were taken at each test level for analysis, with four more taken and held as back-ups. Samples were thawed in a waterbath at about 30°C and concentrated 100:1 by extraction with hexane prior to analysis. The hexane was evaporated and the residue was dissolved in acetonitrile and then diluted with water.

- Sample storage conditions before analysis: All samples taken during aquatic testing were frozen after collection and were kept frozen until they were prepared for analysis

Vehicle:

yes

Remarks:

Water and dimethylformamide (DMF) controls were used

Details on test solutions:

Test solutions (250 mL per replicate) were delivered intermittently (about every 20 minutes; 72 1-L volume additions per day) to replicate feeder cups which then flowed into replicate exposure chambers from a modified Mount and В rungs Proportional Diluter. Test solutions were created by diluting stock DPX-JE874-221 solutions in 1000 mL of daphnid dilution water in the mixing chambers of the diluter. Stock solutions were delivered via a Rainin Rabbit-Plus® peristaltic pump. Test solutions in mixing chambers were continuously stirred by a Teflon® stir bar driven by a magnetic drive.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Age at study initiation (mean and range, SD): Neonates (less than 24 hours old)
- Method of breeding: Parent Daphnia magna were reared at Haskell Laboratory

Test type:

flow-through

Water media type:

freshwater

Remarks:

Haskell Laboratory well water

Total exposure duration:

21 d

Hardness:

73 - 82 mg/L as CaCO3

Test temperature:

20.9 - 21.9°C

pH:

7.5 - 7.8

Dissolved oxygen:

6.2 - 7.9 mg/L

Conductivity:

169 - 179 µhos/cm

Nominal and measured concentrations:

Nominal: 0.11, 0.40, 1.4, 4.9, and 17 µg/L.
Measured: 0.085, 0.29, 1.1, 3.7, and 15 µg/L

Details on test conditions:

Feeder cups were Pyrex® glass cylinders with a hole in the bottom. A Teflon® cork containing a 1-mL disposable glass pipette was inserted into the hole. Test solutions drained by gravity from the feeder cup through the pipette into the test chambers. Test chambers were 1L Pyrex® glass beakers with two parts covered with Nitex® netting (209 цт mesh opening) to allow free test solution entrance/exit from the beaker (to prevent the escape of neonates). Each test chamber contained approximately 600 mL of test solution (about 7.5-cm depth).

Test chambers were suspended in a fixed position in an aquarium. These aquaria [38-L total volume: 50 x 25 x 31 cm; one quadrant: 25 x 12.5 x 31 cm] were constructed of glass and were split into four equal quadrants by glass plates. One replicate test chamber containing daphnids was suspended in each of the four aquarium sections. Each replicate chamber was supplied with a virtually continuous supply of new incoming test solution.

Daphnids were fed Selenastrum capricornutum and Ankistrodesmus falcatus, at a rate of 1,563 cells/mL/cycle of each species giving a total calculated algal density of 3,126 cells/mL cycle. Approximately 6 mL/hour of concentrated algal suspension was pumped continuously into each feeder cup from a Rainin Rabbit-Plus® peristaltic pump. This algal aliquot is diluted with 250 mL of test solution and drains by gravity into the test chamber containing the daphnids. Hence, the daphnids have a continuous supply of algae throughout the 21-day test.

A photoperiod of 16 hours light (86.08 - 107.6 lux) versus 8 hours darkness was employed with approximately 30 minutes of transitional light (4.304 lux) preceding and following the 16-hour light interval.

Ten neonates were assigned to each test chamber using random numbers (four replicates per concentration; 40 neonates per concentration). Neonates were initially placed into secondary containers and then transferred into the test chambers under the water surface beginning with the controls and moving from low to high concentrations. This procedure avoids exposing daphnids to incorrect DPX-JE874-221 concentrations from the transfer pipette. The loading of the daphnids in each test chamber was one daphnid per 60 mL of test solution.

Observations were made at least daily. The criterion for immobility was the inability to swim at least two body lengths in any direction within 15 seconds after prodding with a glass rod. Observations included whether daphnids were mobile or immobile, presence / absence of floating daphnids, presence / absence of offspring, whether offspring were mobile or immobile, and presence / absence of floating offspring. Immobile adults were removed as noted. Prior to the onset of reproduction, each replicate was examined daily to see if offspring were present. Once reproduction began, on Tuesdays, Thursdays, Saturdays and Sundays reproduction was noted simply as present or absent. On Mondays, Wednesdays, and Fridays, the total number of offspring in each replicate was counted and removed.

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

15 µg/L

Basis for effect:

other: total live young per mobile adult and adult mobility

Duration:

21 d

Dose descriptor:

other: MATC

Effect conc.:

7.5 µg/L

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

3.7 µg/L

Details on results:

Floating first-generation daphnids were observed on 11 occasions. Floating, second generation neonates were also observed from day 14 to day 21 of the study. The biological significance and relationship to chemical exposure (if any) is unknown. The presence of floating first or second generation daphnids was not a dose related response but seen sporadically throughout all concentrations and controls.

Adult mobility data were analyzed at 48 and 96 hours, and 7, 14, 21 days (there was
zero immobility at 24 hours), and reproduction end points were analyzed at 14 and 21 days. Calculations were performed using mean, measured concentrations of DPX-JE874. Significant differences were found between the two controls for length at 21 days (3.41 mm for the water control, 3.72 mm for the DMF control). Consequently, only the DMF control was used for this endpoint. For first day of reproduction, total live young per mobile adult, total live young, total mobile adults, and total immobilized young at 21 days, no significant differences between the two controls were found and they were combined for analysis of these endpoints. The average total number of neonates per mobile daphnid in the water and DMF controls were 75 and 79,
respectively. The no observable effect concentration, NOEC, for total live young per mobile adult at 13 and 21 days was 3.7 µg/L. The EC50 for total live young per mobile adult at 13 days was 9.10 µg/L with 95% fiducial bounds of 6.5 and 17 µg/L, while at 21 days, the EC50 was 8.0 µg/L with 95% fiducial bounds of 6.3 and 11 µg/L.

The 48- and 96-hour, 7-, 14-, and 21-day EC50 values, based on adult mobility, were 17, 19, 14, 13, and 7.9 µg/L, respectively. The NOEC for total mobile adults was 3.7 µg/L for all time periods except for the 24 hour and 14-day data. There was no immobility at 24 hours, so no test was necessary or possible. The NOEC for day 14 was 0.29 µg/L, but this result is not considered to be biologically significant because of the non-monotone data at days 14 and the 3.71 µg/L NOEC for this parameter at 21 days.

First day of reproduction was delayed at 15 µg/L but the difference was not statistically significant. However, this delay was biologically significant and therefore the NOEC was 3.7 µg/L. Only one immobile young was found throughout the study, at 1.1 µg/L; this one immobility was not considered to be related to DPX-JE874-221 exposure. The NOEC for total live young at 13 days and length of mobile adults at 21 days was 3.71 µg/L Although statistical analyses determined the NOEC to be 0.29 µg/L for total live young at 21 days and total mobile adults at 14 days, this finding was believed to be spurious due to the non-linear dose response. Since a downward trend is the trend of interest and total live young per mobile adult at 21 days was significantly reduced only at 15 µg/L, the NOEC was 3.7 µg/L. The 21 day EC50 values for total live young and total live young per mobile adult were 7.5 and 8.0 µg/L, respectively.

Validity criteria fulfilled:

yes

Conclusions:

The no observable effect concentration (NOEC), maximum acceptable toxicant concentration (MATC), and the lowest observed effect concentration (LOEC) were 3.7, 7.5, and 15 µg/L based on total live young per mobile adult at 21 days and adult mobility at 21 days.

Executive summary:

Chronic toxicity of DPX-JE874-221 was evaluated by exposing Daphnia magna neonates (less than 24-hours old) for 21 days in a flow-through test. Nominal concentrations were 0.11, 0.40, 1.4, 4.9, and 17 µg/L. It must be noted that the lowest level (0.11 µg/L)is just below the calculated limit of detection and so these results must be considered with care. Water and dimethylformamide (DMF) controls were used. Mean, measured concentrations were 0.085, 0.29, 1.1,3.7, and 15 µg/L, respectively. Active ingredient, DPX-JE874, was not detected in either of the two controls. Adult mobility data were analyzed at 48 and 96 hours, and 7, 14, 21 days (there was zero immobility at 24 hours), and reproduction end points were analyzed at 14 and 21 days. Calculations were performed using mean, measured concentrations of

DPX-JE874. Significant differences in adult length were found between the two controls at 21 days (3.41 mm for the water control and 3.72 mm for the DMF control). Consequently, only the DMF control was used for this endpoint.

 

For first day of reproduction, total live young per mobile adult, total live young, total mobile adults, and total immobilized young at 21 days, no significant differences between the two controls were found and they were combined for analysis of these endpoints. The average

total number of neonates per mobile daphnid in the water and DMF controls were 75 and 79, respectively. The no observable effect concentration, NOEC, for total live young per mobile adult at 13 and 21 days was 3.7 µg/L. The EC50 for total live young per mobile adult at 13 days was 9.10 µg/L with 95% fiducial bounds of 6.5 and 17 µg/L, while at 21 days, the EC50 was 8.0 µg/L with 95% fiducial bounds of 6.3 and 11 µg/L.

 

The 48- and 96-hour, 7-, 14-, and 21-day EC50 values, based on adult mobility, were 17, 19, 14, 13, and 7.9 µg/L, respectively. The NOEC for total mobile adults was 3.7 µg/L for all time periods except for the 24 hour and 14-day data. There was no immobility at 24 hours, so no test was necessary or possible. The NOEC for day 14 was 0.29 µg/L, but this result is not considered to be biologically significant because of the non-monotone data at days 14 and the 3.7 µg/L NOEC for this parameter at 21 days.

 

First day of reproduction was delayed at 15 µg/L but the difference was not statistically significant. However, this delay was biologically significant and therefore the NOEC was 3.7 µg/L. Only one immobile young was found throughout the study, at 1.1 µg/L; this one immobility was not considered to be related to DPX-JE874-221 exposure. The NOEC for total live young at 13 days and length of mobile adults at 21 days was 3.7 µg/L. Although statistical analyses determined the NOEC to be 0.29 µg/L for total live young at 21 days and total mobile adults at 14 days, this finding was believed to be spurious due to the non-linear dose response. Since a downward trend is the trend of interest and total live young per mobile adult at 21 days was significantly reduced only at 15 µg/L, the NOEC was 3.7 µg/L. The 21 day EC50 values for total live young and total live young per mobile adult were 7.5 and 8.0 µg/L, respectively.

 

In conclusion, the no observable effect concentration (NOEC), maximum acceptable toxicant concentration (MATC), and the lowest observed effect concentration (LOEC) were 3.7, 7.5, and 15 µg/L, based on total live young per mobile adult at 21 days and adult mobility at 21 days.

Description of key information

Freshwater

21-day NOEC (Daphnia magna) = 3.7 μg/L, OECD 202, OPP 72-4, Reliability = 1

Saltwater

21- NOEC (Mysidopsis bahia) = 0.830 μg/L, OPP 72-4, Reliability = 1

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

NOEC

Remarks:

21-day

Effect concentration:

3.7 µg/L

Marine water invertebrates

Marine water invertebrates

Dose descriptor:

NOEC

Remarks:

28-day

Effect concentration:

0.83 µg/L

Additional information

Famoxadone was tested in two long term tests in aquatic organisms resulting in a 21-day NOEC in Daphnia magna of 3.7 μg/L and a 28-day NOEC in Mysidopsis bahia of 0.830 μg/L.