3-iodo-2-propynyl butylcarbamate

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

fish short-term toxicity test on embryo and sac-fry stages

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1992-06-22

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)

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 9102-6111

Analytical monitoring:

yes

Details on sampling:

Sample storage conditions before analysis:
The dilution water control and the high, middle, and low test concentrations were sampled and analyzed for test item concentration twice prior to the start of the definitive exposure. During the in-life phase of the definitive study, water samples were removed from both replicate test solutions of each treatment level and the controls on test days 0, 5,12,19, 26,29, 33 and 35 for analysis of test material concentration. Three Quality Control (QC) samples were also prepared at each sampling interval and remained with the set of exposure solution samples throughout the analytical process

Vehicle:

yes

Remarks:

acetone

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Stock solutions at a concentration of 9.8 mg/mL were prepared on test days -1,6,13, 20, 27 and 33 by dissolving the appropriate amount of test item with acetone (CAS #67-64-1) to a total volume of 50 mL.
- Controls: no treatment control, vehicle control
- Chemical name of vehicle: acetone
- Concentration of vehicle in test medium: maximum amount present in any test concentration (0.010 mL/L)
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): no

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: fathead minnow
- Strain: brood stock maintained at Springborn Laboratories Inc.
- Age at study initiation: < 24 h
- Feeding during test: During the definitive test, subsequent to the completion of hatch (day 5), the fry were fed live brine shrimp nauplii (Memia salina) three times daily on weekdays and two times daily on weekends.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

35 d

Remarks on exposure duration:

30 d post hatch

Hardness:

24 - 30 mg/L

pH:

6.8 - 7.0

Conductivity:

110 - 140 µmhos/cm

Nominal and measured concentrations:

nominal: 100; 50 ; 25; 12; 6.2 µg/L
measured: 57; 27; 19; 8.4; 4 µg/L

Details on test conditions:

TEST SYSTEM
- Embryo cups: 14 glass jars (5 cm O.D., 8 cm high) with 40-mesh Nitex screen bottoms.
- Test vessel: each test aquarium measured 39 x 20 x 25 cm with a 14.5-cm high side drain that maintained a constant exposure solution volume of approximately 11 L
- Type of flow-through: proportional diluter
- Renewal rate of test solution: 6.5 aquarium volumes per 24 h, 90 % replacement time of approx. 8.5 h
- No. of fertilized eggs/embryos per vessel: 60
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The dilution and control water was well water which was pumped into an epoxy-coated concrete reservoir where it was supplemented with Town of Wareham untreated well water and aerated
- Total organic carbon: Based on monthly analyses, the TOC concentration of the dilution water source was determined to be 1.1 and 0.38 mg/L for the months of September and October 1991, respectively
- Pesticides: In accordance with requirements stated within the EPA-GLP regulations, routine analyses were also conducted on representative samples from the dilution water source for the presence of pesticides and PCB's. None of these compounds have been detected at concentrations that are considered toxic in any of the water samples analyzed in agreement with US EPA and ASTM guidelines.
- Alkalinity: 19-25 mg/L
- Ca/mg ratio: 24-30 mg/L
- Culture medium different from test medium: no
- Intervals of water quality measurement: During the study, weekly characterization of the well water was performed


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light, 8 h dark
- Light intensity: 20-55 footcandles (equivalent to approx. 215.3 - 592.0 lux)

EFFECT PARAMETERS MEASURED: embryo survival at hatch, larval survival, total length and wet weight

VEHICLE CONTROL PERFORMED: yes

Reference substance (positive control):

no

Key result

Duration:

35 d

Dose descriptor:

LOEC

Effect conc.:

19 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: length and weight

Key result

Duration:

35 d

Dose descriptor:

NOEC

Effect conc.:

8.4 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: length and weight

Key result

Duration:

35 d

Dose descriptor:

other: Maximum Acceptable Toxicant Concentration (MATC)

Effect conc.:

> 8.4 - < 19 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: length and weight

Details on results:

- Overall mortality/survival: At test termination (day 35) larval surviving ranging from 76-90 % was recorded in all test item concentrations. There were no statistical significant differences to the control in any of the treatment groups

- Length and weight of surviving fish: Statistical analysis demonstrated a significant reduction (p <0.05) in larval length in all three of these treatment level solutions when compared to the mean total length of the pooled control larvae (32.7 mm). The mean total length in the remaining concentrations (8.4 and 4.0 µg/L) was 32.7 and 33.1, respectively, and was comparable to the pooled control organism data. Similarly, the mean wet weight of organisms exposed to the three highest treatment levels (57, 27 and 19 µg/L) was 189, 266 and 284 mg, respectively, and was significantly reduced when compared to the mean wet weight of the pooled control organisms (340 mg). The mean wet weight of larvae exposed to the 8.4 and 4.0 µg/L treatment levels was 329 and 343 mg, respectively.

- Effect concentrations exceeding solubility of substance in test medium: no
- Incidents in the course of the test which might have influenced the results: no

Results with reference substance (positive control):

not applicable

Validity criteria fulfilled:

yes

Conclusions:

In this study early life stages of fathead minnow were exposed to test item concentrations of 57; 27; 19; 8.4; 4 µg/L (measured). Body length and wet weight were found to be the most sensitive indications of the test item toxicity. A respective NOEC was determined to be 8.4 µg/L.

Executive summary:

The objective of this study was to determine the effects of test item on fathead minnow (Pimephales promelas) embryos and larvae during continuous aqueous exposure. Test concentrations were selected based on the results of preliminary flow-through exposures of juvenile fathead minnows. The definitive embryo/larval exposure was initiated within 24 hours after egg fertilization and continued through 35 days (30 days post-hatch). The effects on embryo survival at hatch and on survival and growth (wet weight and total length) of larvae at test termination were measured and used to estimate LOEC, NOEC and the Maximum Acceptable Toxicant Concentration (MATC).

Description of key information

In a GLP and guideline compliant study, early life stages of fathead minnow were exposed to test item concentrations of 57; 27; 19; 8.4; 4 µg/L (measured). Body length and wet weight were found to be the most sensitive indications of the test item toxicity. Respective NOEC was determined to be 8.4 µg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

8.4 µg/L

Additional information

Fish toxicity test on embryo and sac-fry stages

The objective of this study was to determine the effects of test item on fathead minnow (Pimephales promelas) embryos and larvae during continuous aqueous exposure. Nominal test concentrations were 100; 50 ; 25; 12; 6.2 µg/L and were selected based on the results of preliminary flow-through exposures of juvenile fathead minnows. The definitive embryo/larval exposure was initiated within 24 hours after egg fertilization and continued through 35 days (30 days post-hatch). The effects on embryo survival at hatch and on survival and growth (wet weight and total length) of larvae at test termination were measured and used to estimate LOEC, NOEC and the Maximum Acceptable Toxicant Concentration (MATC).