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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
Lot No 503881
Specific details on test material used for the study:
Lot 503881

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Water samples were collected from freshly prepared batch (or pooled replicate samples as in
the Rainbow trout) of test solution for each treatment group and control at test initiation. All samples
were collected from mid-depth in the test solutions, placed in glass vials, and processed immediately
for analysis.

Test solutions

Vehicle:
yes
Details on test solutions:
A primary stock solution was prepared in U.V. sterilized well water at a nominal
concentration of 5.0 mg/L. The stock was sonicated for ~ 5 minutes and inverted to mix.
The primary stock solution appeared clear and colorless. Proportional aliquots of the primary
stock solution were diluted with U.V. sterilized well water to prepare the 0.063, 0.13, 0.25,
0.50, 1.0 and 2.0 mg/L test solutions. The test solutions appeared clear and colorless.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Species: Cladoceran (Daphnia magna)
Source: Wildlife International, Ltd. Cultures
Age at Test Initiation: Neonates <24 hours
Feeding: Daphnids in the cultures were fed a mixture of yeast, cereal grass media, and
trout chow, as well as a suspension of the freshwater green alga,
Pseudokirchneriella subcapitata. The adults were fed prior to test initiation,
but neonates were not fed during the test.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h

Test conditions

Hardness:
136 mg/L as CaCO3
Test temperature:
20ºC, consistent within +/- 1ºC (20.2 – 20.9ºC)
pH:
8.3-8.5
Dissolved oxygen:
8.5 – 9.2 = >94% ASV
Conductivity:
306 µmhos/cm
Nominal and measured concentrations:
nominal concentrations: 0, 0..63, 0.13, 0.25, 0.50, 1.0, 2.0 mg/L
measured concentrations: 0, 0.074, 0.13, 0.22, 0.43, 0.85, 1.4 mg/L
Details on test conditions:
Photoperiod: 16-hrs light; 8-hrs dark
Test Vessels: 250 mL glass beakers
Test Volume: 220 mL
Loading: 10 daphnids/replicate
Number of Replicates: Dose-response test – 2
Dilution Water: Water used for culturing and testing of the daphnids was obtained from a
well located on the Wildlife International Ltd. site. Well water characteristics
(Mean of 4 weekly measurements taken prior to test initiation): Hardness
(136 mg/L as CaCO3,); Alkalinity (181 mg/L as CaCO3); Conductivity (306
µmhos/cm) and pH (8.2).
Test Temperature: 20ºC, consistent within +/- 1ºC (20.2 – 20.9ºC)
Test Solutions pH: 8.3 – 8.5
Test Solutions DO: 8.5 – 9.2 = >94% ASV
Exposure Period: 48 hours
Effect: Organisms not able to swim after gentle agitation of the test container are
considered dead.
Measurements: DO at 0, 24 and 48 hours; Temperature and pH at test initiation and
termination; Temperature measured continuously in adjacent beaker of water.
Procedure: Observations of mortality and clinical signs of toxicity at 0-24, 24 and 48
hours. Mortality data at 24 and 48 hours were used to determine EC50
values.

Results and discussion

Effect concentrations
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 2 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The LC50 of Daphnia magna, Exposed to Maropitant for 48-Hours under Static Test Conditions was determined to be >2.0 mg/L (nominal)