Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
from 2005 january 21st to 2005 january 26th
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study performed according to the OECD Guideline 202.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2005
Report Date:
2005

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Sample Reference No. : DEV75332
Appearance : Tan powder
Aqueous solubility : < 0.05 mg/L
Structure confirmation : Confirmed to be consistent with the proposed structure
Purity determination : 98.8 wt.%
Stability : Stable

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
The test organisms were cultured within the testing facility. An organism origination
statement and taxonomic verification are located in a central file maintained by the
Ecotoxicology group, Room 2020, Building 320, Kodak Park. The following taxonomic
characterization applies to the daphnids:
Phylum - Arthropoda
Class - Crustacea
Order - Cladocera
Family - Daphnidae
Genus - Daphnia
Species - magna (Straus)
The test organisms are cultured in 100-L stainless steel tanks provided with a continuous
flow of filtered-treated-tempered water. The water depth is maintained by use of an
overflow pipe that discharges into a floor drain. The tanks are continuously aerated by
passing oil-free filtered air through air stones. The culturing facility is maintained at a
constant temperature of 20°C and is illuminated with fluorescent lighting for 16 hours
followed by a 30-minute transition period leading to 8 hours of darkness.
The daphnids are fed an ample amount of spinach-yeast-fish food slurry that may be
supplemented with a yeast-Cerophyll leaves-trout chow (YCT) mixture or green algae,
such as Selenastrum capricornutum. The dietary components of the YCT are analyzed
routinely to identify contaminants that could interfere with the outcome of the study. The
findings of these analyses are located in a central file maintained by the Ecotoxicology
group. No known contaminants at concentrations that could interfere with the outcome of
studies have been identified.
The colonies are observed daily and maintenance is performed as necessary. Logbooks
are maintained that document organism feeding, behavioral observations,
physio-chemical parameters and maintenance activities.

Study design

Test type:
static
Water media type:
freshwater
Total exposure duration:
48 h

Test conditions

Test temperature:
The temperature of the test substance solutions ranged from 19.6 to 19.7°C.
pH:
The pH of the test substance ranged from 8.2 to 8.3.
Dissolved oxygen:
The dissolved oxygen concentrations of the test substance solutions ranged from 9.1 to 9.3 mg/L.
Nominal and measured concentrations:
Exposure solutions containing the test substance at nominal concentrations of 0.1 mg/L
were tested. The exposure solutions were prepared by direct addition of a stock solution
containing the test substance to test media. Two test substance stock solutions were
prepared by weighing approximately 25.1 and 25.6 mg of test substance into weigh boats
and transferring it into separate 25-mL volumetric flasks. The flask was then brought to
volume with a solvent, N,N-dimethyl formamide (DMF). The 0.1-mg/L test substance
exposure solutions were prepared by pipetting 2 mL of stock solution into 22-L mixing
vessels containing 20 L of laboratory dilution water. Carrier solvent control solutions
were also prepared by pipetting 2 mL of DMF into 20 L of laboratory dilution water. The
solutions were stirred for approximately 2 hours using stir plates and Teflon-coated stir
bars. A 200-mL aliquot was removed from the middle of each mixing vessel’s water
column and transferred into the 250-mL test vessels.
Details on test conditions:
Study Observations
The physical parameters of the exposure solutions were measured at test start and test
end.
The appearances of the exposure solutions were observed and recorded at test start, after
4 hours of exposure and at the end of each 24-hour period.
The test organisms were observed for behavioral abnormalities at test start, after 4 hours
of exposure and at the end of each 24-hour period.
Collection of Samples for Concentration Verification
Samples of the controls and test substance exposure solutions were analyzed at test start
and test end to verify test substance concentration. The samples analyzed at test start
were collected from approximately mid-depth of the 22-L mixing vessels using a
spigot-valve assembly. The samples analyzed at test end were poured from the 250-mL
test vessels into the sample containers. Samples were analyzed using HPLC/UV.

Results and discussion

Effect concentrationsopen allclose all
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
> 0.11 mg/L
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 0.11 mg/L
Basis for effect:
mobility

Applicant's summary and conclusion

Conclusions:
The results of this study indicate that the 48-hour EC50 value is greater than the measured
aqueous solubility of the substance. Based on this test, the test substance would not be classified
according to the European Union’s labeling directive [ l l ] and would correspond to a “low
concern level” according to the U.S. EPA’s assessment criteria [12].