Registration Dossier

Ecotoxicological information

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP Guideline study but made with the formulation product.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report Date:
1999

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
other: "OECD Guidelines for Testing of Chemicals", Draft Guideline 202, Part II, Daphnia magna Reproduction Test, Organization for Economic Cooperation and Development. Paris, 1996
Qualifier:
according to
Guideline:
other: USEPA. 1986. Daphnia magna Life Cycle (21 -Day Renewal) Chronic Toxicity Test. Office of Pesticides Programs, Washington, DC. EPA- 540/9-86-141
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Fenoxaprop-P-ethyl + AE F1 22006; emulsifiable concentrate; 69 + 75 g/L

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: On Day 0 and each renewal day (i.e., every Monday, Wednesday, and Friday), a stock solution was prepared by weighing approximately 18 mg of the test substance, transferring it to a 9-L Pyrex® carboy, and adding 6 Liters of synthetic hard water. The stock solution had a final concentration of 3.0 mg/L.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: water flea
- Source: obtained from inhouse cultures reared in the Ecotoxicology Laboratory at the AgrEvo Research Center since September 14, 1993.
- Age of parental stock: Neonates used in the study were obtained from 19 day old parents at the time of testing. The parental culture had a cumulative adult survival greater than or equal to 80%, no behavioral signs of stress, and no ephippia.
- Feeding during test
- Food type: green algae, P. subcapitata and TetraFin fish food
- Amount and Frequency: On a daily basis, all test chambers were manually fed 0.2 mL (individual) or 1 .0 mL (group) of a green algae, P. subcapitata,
stock solution (1 .0 x 1 0 cells/mL). This was equivalent to a rate of 2.0 x 107 cells/daphnid/day. At each renewal, test chambers were supplemented with 0.1 mL (individual) or 0.5 mL (group) of a suspension of TetraFin fish food at 5.0 mg dry solids/mL.


HOUSING
- Housing conditions (same as test or not): Same as test. No acclimation was necessary since the organisms were cultured in dilution water that was of identical composition as the test dilution water and at the same temperature.
- Type and amount of food: unicellular green algae, Pseudokirchneriella subcapitata and TetraFin fish food suspension.
- Feeding frequency: twice daily

Study design

Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
21 d

Test conditions

Hardness:
164 to 170 mg/L as CaCO3
Test temperature:
Temperature measurements in fresh test solutions ranged from 19.5 to 20.5 °C while old test solutions ranged from 19.0 to 20.0 °C.
pH:
The pH values in fresh test solutions ranged from 7.4 to 7.8 while old test solutions ranged from 7.9 to 8.7.
Dissolved oxygen:
Dissolved oxygen ranged from 96 to 99% saturation in fresh solutions while old test solutions ranged from 90 to 113% saturation.
Nominal and measured concentrations:
Nominal test concentrations of formulated test substance: 0.19, 0.38, 0.75, 1.5, and 3.0 mg/L.
The nominal concentrations of the active ingredient fenoxaprop-P-ethyl (6.95% w/w) were 0.013, 0.026, 0.052, 0.10, and 0.21 mg/L. The nominal
concentrations of the safener AE F122006 (7.30% w/w) were 0.014, 0.028, 0.055, 0.11, and 0.22 mg/L.
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: Glass beakers for individual and group daphnids, respectively. The test chambers for individuals contained approximately 80 mL of solution. Approximate individual test chamber dimensions were 4.6 cm in diameter, and 7.0 cm high, with a test solution depth of approximately 4.9 cm. The test chambers for groups contained approximately 400 mL of solution. Approximate group test chamber dimensions were 8.4 cm in diameter, and 12.4 cm high, with a test solution depth of approximately 7.8 cm. All test chambers were covered to prevent entry of foreign materials
- Renewal rate of test solution: every monday, wednesday and friday.
- No. of organisms per vessel: 1 and 5
- No. of vessels per concentration (replicates): there were 10 replicates of individual daphnids and 3 replicates of groups of 5 daphnids for a total of
25 organisms.
- No. of vessels per control (replicates):


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: synthetic hard water, according to guideline
- Intervals of water quality measurement: measurements of temperature, dissolved oxygen, pH, and specific conductivity were obtained at each renewal periodWater quality parameters were measured on the newly prepared parent stock solutions and on one replicate of each old test solution, alternating the replicate each time.

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: A 16:8, light:dark photoperiod was provided.
- Light intensity: 720 lux (i.e., 67 foot candles); cool-white fluorescent tubes

EFFECT PARAMETERS MEASURED: Observations for death, immobility, and abnormal appearance or behavior were performed daily on each replicate chamber (both individual and group). Starting on Day 6, all individual daphnids were checked daily for initial neonate production. At termination of the study, surviving adult daphnids were measured from the apex of the helmet to the base of the spine using a dissecting microscope and ocular micrometer. Adult daphnids for each replicate were then dried in a laboratory oven at approximately 70 °C for approximately 96 hours and weighed.



RANGE-FINDING STUDY
- Results used to determine the conditions for the definitive study: No range finding test was performed. Treatment concentrations were chosen based on results from daphnia acute tests on both the active ingredients, seperately and this formulated test substance. No 48 hour EC50 values could be generated up to the maximum solubilities of fenoxaprop-P-ethyl or AE F122006 in synthetic hard water (1.0 and 0.51 mg/L, respectively). The 48 hour EC50 of this formulation in the acute test was 3.6 mg/L (95% CL = 3.2 to 4.2 mg/L). The lowest observed effect concentration was 3.6 mg/L. The no observed effect concentration was 2.2 mg/L. Therefore, the definitive study was conducted at the nominal test concentrations of 0.19, 0.38, 0.75, 1.5, and 3.0 mg/L.
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
1.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
immobilisation
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
0.38 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth
Remarks:
(length)
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
1.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth
Remarks:
(weight)
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
0.75 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
reproduction

Any other information on results incl. tables

The No Observed Effect Concentration (NOEC) and Lowest Observed Effect Concentration (LOEC) for survival, growth and reproduction of D. magna are tabulated below:

Parameter

NOEC (mg/L)

LOEC (mg/L)

Parental Survival

1.5

3.0

Growth (Length)

0.38

0.75

Growth (Weight)

1.5

NCa

Reproduction (young/adult)

0.75

1.5

a NC = Not calculable; no decrease in weight was evident.

Based on the most sensitive endpoint of daphnid length for this study, the NOEC

is 0.38 mg/L and the LOEC is the 0.75 mg/L. The MATC (Maximum Allowable

Toxicant Concentration), calculated as the geometric mean of the NOEC and

LOEC, is 0.53 mg/L.

 

Conclusion

In a static renewal exposure for 21 days, fenoxaprop-P-ethyl + AE F122006 emulsifiable concentrate has chronic effects on the growth of the water flea, D.

magna,at a concentration of 0.75 mg/L, but no effects were observed at a concentration of 0.38 mg/L. Analysis of test solution: No safener (AE F122006) was found in the dilution water or control samples. The mean measured AE F122006 concentrations in the treated study samples (fresh solutions) were 0.01, 0.02, 0.04, 0.1, and 0.2 mg/L which represents a range of 75 to 91% of the nominal concentrations. No AE F122006 was found in the 72 hour old solutions.

No AE F046360 was found in the dilution water at levels greater than the limit of quantitation (0.003 mg/L). The control samples on study Days 2 and 5 had measured levels of fenoxaprop-P-ethyl found of 0.006 and 0.007 mg/L, respectively. Several other control samples (both fresh and old solutions) had values of less than the limit of quantitation found. The mean measured AE F046360 concentrations in the treated study samples (fresh solutions) were 0.02, 0.04, 0.06, 0.1, and 0.2 mg/L which represents a range of 105 to 152% of the nominal concentrations. The mean measured AE F046360 concentrations in the treated 72 hours old study samples were 0.003, less than the limit of quantitation, less than the limit of quantitation,

0.04, and 0.03 mg/L which represents a range of 0 to 36% of the nominal concentrations.

No AE F088406 was found in the dilution water or control samples. No AE F088406 residues were found in the freshly prepared samples at levels greater than the limit of quantitation (0.003 mg/L). The mean measured AE F088406 concentrations in the treated 72 hour old study samples were 0.01, 0.02, 0.05, 0.09, and 0.2 mg/L.

Applicant's summary and conclusion