Registration Dossier

Administrative data

Endpoint:
fish early-life stage toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1994
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994
Report Date:
1994

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EPA OPP 72-4 (Fish Early Life-Stage and Aquatic Invertebrate Life-Cycle Studies)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Dead and live embryos were counted daily until hatching was complete. Hatching was deemed complete when no more than 5 unhatched viable embryos remained in any control or treatment level egg incubation cup (exposure day 4). The 31-day post-hatch larvae exposure was initiated when 40 live larvae were impartially selected from the surviving larvae in each incubation cup on study day 4 and placed into their respective exposure aquaria (40 organisms per replicate/80 organisms per treatment level). During the post-hatch exposure period, observations of larval survival, behaviour and appearance were made and recorded daily. Dead larvae were removed at the time of observation. Larval survival was estimated at least twice weekly. At 31 days post-hatch exposure (study termination), the percent larval survival was determined.

Test solutions

Vehicle:
yes
Details on test solutions:
Description of method:
Immediately prior to test start, groups of sixty Fathead minnow eggs, less than 24 hours old, were put into each of 14 incubation cups and maintained at 24 °C. To initiate the test, these incubation cups were then placed into exposure aquaria containing either PB-200 at concentrations of 0.047, 0.094, 0.19, 0.38 and 0.75 mg PBO/L, a solvent control or a blank water control. Acetone was used as solvent at a maximum amount of 0.018 mL/L. The test concentrations were based on results from a preliminary range finding test. Each treatment group was comprised of two replicates and maintained under flow-through conditions. Hatching of embryos was deemed complete four days after test start and numbers hatched were recorded.
The post-hatching exposure phase of the study was then initiated by selecting forty live larvae from each of the incubation cups and placing these into their respective aquaria where they remained for 31 days. During this time, observations of larval survival, behaviour and appearance were recorded daily. Any dead larvae were removed at the time of observation. At termination of the exposure phase, surviving larvae were anesthetized and individually measured for length and weighed for wet weight.
Test aquaria maintained a test solution volume of 15 L and a flow of approximately 6.4 volume replacements every 24 hours.
Water temperature, pH and dissolved Oxygen were recorded daily in each aquarium. Analytical determinations for PB-200 concentration were made from samples taken from each replicate of each treatment group at the start of the study and thereafter on days 4, 11, 18, 21, 25, 28, 31 and 35 (end of the study).

Test guidelines no.:
US EPA 72-4
Relevant deviations from test guidelines:
None

Test organisms

Test organisms (species):
Pimephales promelas
Details on test organisms:
Species/strain Fathead minnow (Pimephales promelas)
Source: Springborn brood stock
Wild caught: No
Age/size: At the start of the study, the test organisms were in the form of eggs less than 24 hours old
Kind of food: Live brine shrimp nauplii (Artemia salina)
Amount of food: Ad libitum
Feeding frequency: Once on day 4 of the study, three times daily thereafter until day 34
Post-hatch transfer time: Not applicable
Time to first feeding: 4 days
Feeding of animals during test: Larvae were not fed during the 24-hours prior to study termination
Treatment for disease within 2 weeks preceeding test: No

Handling of embryos and larvae
The surviving larvae were anesthetized with MS-222 (tricaine methane-sulfonate), measured and weighed individually to calculate the mean and standard deviation of total length and wet weight (OECD 210/212).

Study design

Test type:
flow-through
Total exposure duration:
4 d
Post exposure observation period:
4-day incubation period and a 31-day post-hatch exposure period

Test conditions

Hardness:
32 - 40 mg/L as CaCO3
Test temperature:
25 ± 1°C
pH:
6.9 - 7.4
Dissolved oxygen:
7.2-8.1 mg/L
Details on test conditions:
TEST SYSTEM
Test type: Flow-through
Renewal of test solution: 6.4 aquarium volumes per 24-hour period, with a 90% replacement time of approximately 9.0 hours
Volume of test vessels: 15 L
Volume/animal: 0.375 L/fish
Number of animals/vessel: 40/vessel
Number of vessels/ concentration: 2
Test performed in closed vessels due to significant volatility of TS: No
Aeration of dilution water: Yes. Chemical grade oxygen was gently bubbled via an airstone into the column containing the dilution water.

PREPARATION OF TS SOLUTION FOR POORLY SOLUBLE OR VOLATILE TEST SUBSTANCES
Dispersion: No
Vehicle: Acetone
Concentration of vehicle. 0.0018% (vol/vol)
Vehicle control performed. Yes. A 52% (vol/vol) acetone stock solution was prepared by diluting 259 mL acetone with distilled water to volume in a 500 mL flask

TEST ORGANISMS
Species/strain: Fathead minnow (Pimephales promelas)
Source: Springborn brood stock
Wild caught: No
Age/size: At the start of the study, the test organisms were in the form of eggs less than 24 hours old
Kind of food Live brine shrimp nauplii (Artemia salina)
Amount of food: Ad libitum
Feeding frequency: Once on day 4 of the study, three times daily thereafter until day 34
Post-hatch transfer time: Not applicable
Time to first feeding: 4 days
Feeding of animals during test: Larvae were not fed during the 24-hours prior to study termination
Treatment for disease within 2 weeks preceeding test: No

DILUTION WATER
Source: Well water supplemented with Town of Wareham well water
Alkalinity: 19 – 28 mg/L as CaCO3
Hardness: 32 - 40 mg/L as CaCO3
pH: 7.0 – 7.2
Oxygen content: 7.0 – 8.6 mg/L
Conductance: 130 - 140 µmhos/cm
Holding water different from dilution water: No

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16-hour light and 8-hour dark photoperiod
- Light intensity: Durotest Vitalite® fluorescent lights centrally located above the test aquaria at a range of 25 to 80 footcandles (270 to 860 lux).

Results and discussion

Effect concentrationsopen allclose all
Duration:
35 d
Dose descriptor:
NOEC
Effect conc.:
0.18 mg/L
Nominal / measured:
not specified
Conc. based on:
not specified
Basis for effect:
not specified
Duration:
35 d
Dose descriptor:
LOEC
Effect conc.:
0.42 mg/L
Nominal / measured:
not specified
Conc. based on:
not specified
Basis for effect:
not specified
Details on results:
Range finding test: Performed
Concentrations: 0.19, 0.38, 0.75, 1.5 and 3.0 mg PB-200 / L.
Number/ percentage of animals showing adverse effects: Mortality of 20, 20, 40, 30 and 100 % was observed in the 0.19, 0.38, 0.75, 1.5 and 3.0 mg PB-200 / L test concentrations, respectively. Partial loss of equilibrium was observed in two surviving fish exposed to the 0.75 mg/L treatment level and in one surviving fish exposed to 1.5 mg PB-200 / L.
Nature of adverse effects: Not applicable

RESULTS TEST SUBSTANCE
Initial concentrations of test substance: 0.047, 0.094, 0.19, 0.38 and 0.75 mg PBO/L
Actual concentrations of test substance: 0.040, 0.11, 0.18, 0.42 and 0.80 mg PBO/L
Effect data: The NOEC was determined to be 0.18 mg PBO/L and the LOEC was determined to be 0.42 mg PBO/L. Utilizing these data, the MATC for Task Force Blend PB-200 and Fathead minnow embryos and larvae was determined to be > 0.18 and < 0.42 mg total PBO/L with a geometric mean of 0.27 mg total PBO/L (see the table "Effect data" attached in background material).
Concentration/response curve: see the graphic "Concentration-response" attached in background materia

RESULTS OF CONTROLS
Number/percentage of animals showing adverse effects: see the table "Effect data" attached in background material.
Nature of adverse effects: Not applicable.
Reported statistics and error estimates:
All statistical analyses were conducted at the 95 % level of certainty except in the case of Shapiro-Wilks and Bartlett’s Tests, in which the 99 % level of certainty is preferred for qualifying tests.
(Computer program by Gulley, D.D., Boetler, A.M. and Bergman, H.L. 1991 Toxtat Release 3.3 University of Wyoming, Laramie, Wyoming).

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
NOEC 0.18 mg PBO/L
LOEC 0.42 mg PBO/L

Validity criteria can be considered as fulfilled, see "Validity criteria for fish tests according to OECD 210-212" attached in background material.