reaction mass of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-2H -isothiazol-3-one

Sediment toxicity

Administrative data

Endpoint:

sediment toxicity: long-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Draft OECD Sediment-Water Lumbriculus Toxicity test Using Spiked Sediment Guideline, September 2006

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Test material form:

other: Amber liquid

Details on test material:

- Name of test material (as cited in study report):Kathon(TM) 886F biocide

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Rohm and Haas, Batch No. 0002585863

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature
- Stability under test conditions: Stable at room temperature
- Solubility and stability of the test substance in the solvent/vehicle: Soluble and stable
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: No

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: Dilution in water
- Final dilution of a dissolved solid, stock liquid or gel: 0.50, 1, 2, 4, and 8 mg/kg

OTHER SPECIFICS: Purity of test material was 14%, of which 10.5% CMIT and 3.5% MIT

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

SEDIMENT
- Concentrations: 0 (negative control), 0 (solvent control), 0.50, 1.0, 2.0, 4.0 and 8.0 CMIT/MIT per kg
- Sampling interval: test initiation, day 7 and day 28
- Sample storage before analysis: Not described

PORE WATER
- Concentrations: 0 (negative control), 0 (solvent control), 0.50, 1.0, 2.0, 4.0 and 8.0 CMIT/MIT per kg
- Sampling interval: test initiation, day 7 and day 28
- Sample storage before analysis: Not described

OVERLYING WATER
- Concentrations: 0 (negative control), 0 (solvent control), 0.50, 1.0, 2.0, 4.0 and 8.0 CMIT/MIT per kg
- Sampling interval: test initiation, day 7 and day 28
- Sample storage before analysis: Not described

Test substrate

Vehicle:

yes

Details on sediment and application:

PREPARATION OF SPIKED SEDIMENT
- Pooling or mixing of different substrates: Not described
- Method of mixing: Not described
- Details of spiking: Not described
- Equilibration time: 48 hours
- Equilibration conditions: Not described
- Controls: Negative control, vehicle control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Acetone
- Concentration of vehicle in test medium (stock solution and final test solution): Not described
- Evaporation of vehicle before use: Yes

Test organisms

Test organisms (species):

Lumbriculus variegatus

Details on test organisms:

TEST ORGANISM
- Common name: Oligochaete
- Strain/clone: Lumbriculus variegatus
- Source: Aquatic Research Organisms, Hampton, New Hampshire, USA
- Details on collection: Thirteen days prior to test initiation, adult oligochaetes (worms) were artificially fragmented in the median body region using a scalpel. The anterior worm sections were discarded and the posterior worm sections were retained for use in the study.
- Age of parental stock (mean and range, SD): Not described
- Breeding conditions: Not described
- Handling of egg masses and larvae: Not described
- Age of animals at beginning of exposure: Synchronized adults
- Feeding during test
- Food type: Salmon starter
- Amount: 200 mg (28-day ration of food)
- Frequency: At test initiation

Study design

Study type:

laboratory study

Test type:

semi-static

Water media type:

freshwater

Type of sediment:

artificial sediment

Limit test:

no

Exposure duration

Duration:

28 d

Exposure phase:

total exposure duration

Test conditions

Hardness:

144 to 160 mg/L as CaCO3

Test temperature:

19.8 to 21.7 °C

pH:

8.1 to 8.5

Dissolved oxygen:

≥ 5.6 mg/L (62 % saturation)

Salinity:

Not applicable

Ammonia:

Not described

Conductivity:

325 to 350 µmhos/cm

Nominal and measured concentrations:

Nominal: 0.50, 1.0, 2.0, 4.0 and 8.0 mg CMIT/MIT per kg dry sediment
Measured: 0.15, 0.15, 0.27, 0.37, 0.46 mg CMIT/MIT per kg dry sediment

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 1 liter glass jars
- Sediment volume: 200 g
- Overlying water volume: 600 mL
- Depth of sediment and overlying water: 2 cm of sediment and 8 cm of overlying water

EXPOSURE REGIME
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 7 replicates for 0.50, 1.0, 2.0 and 4.0 mg CMIT/MIT/kg (dry sediment) groups; and 12 replicates for 8.0 mg CMIT/MIT/kg (dry sediment) group.
- No. of replicates per control / vehicle control: 14 replicates for negative control and solvent control groups
- Feeding regime: Not described
- Type and preparation of food: Salmon starter
- Amount of food: 200 mg (28-day ration of food)

RENEWAL OF OVERLYING WATER
- Details on volume additions: The overlying water was partially renewed (300 ml) on days 7 and 14 due to rising levels of ammonia in the overlying water.

OVERLYING WATER CHARACTERISTCS
- Type of water (e.g. deionized, ground water, sea water, Elendt medium acc. to OECD 219): Well water filtered and ultraviolet sterilized
- Conductivity: 325 to 350 µmhos/cm

CHARACTERIZATION OF (ARTIFICIAL; delete if not applicable) SEDIMENT
Not described

OTHER TEST CONDITIONS
- Light quality: Fluorescent bulbs that emitted wavelengths similar to natural sunlight.
- Photoperiod: 16 h daylight, 8 h dark with 30 minute transition periods
- Light intensity: 381 lux at the surface of the water

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Not described

VEHICLE CONTROL PERFORMED: yes

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

0.27 mg/kg sediment dw

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

mortality

Details on results:

- Mortality of test animals at end of exposure period: 22% reduction in survival at 4.00 mg/kg dry sediment and 92% reduction at 8.00 mg/kg dry sediment
- Changes in body weigth of live adults (% of initial weight) at end of exposure period: Not examined
- No. of offspring produced: Not examined
- Morphological abnormalities: No
- Behavioural abnormalities: A few organisms on the surface of the sediment or climbing the walls of the test chambers in all treatment groups and controls

Reported statistics and error estimates:

The results of the test were based on the nominal sediment concentrations. The NOEC and LOEC were determined by visual interpretation of the dose-response pattern and statistical analyses of the survival/reproduction and dry weight data. Using the statistical program TOXSTAT version 3.5 the survival/reproduction and dry weight (growth) data were evaluated for normality (Chi-Square Test) and homogeneity of variances (Bartlett’s Test or Levene’s Test). After the data was deemed normal with homogeneous variance, the survival/reproduction and dry weight data were analyzed using Bonferroni t-test to identify those treatment levels that were statistically different (p<0.05) from the pooled control group.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

A 28d NOEC (survival) of 0.27 mg a.s./kg dry weight was determined for CMIT/MIT

Executive summary:

Study was conducted according to OECD draft Sediment-WaterLumbriculusToxicity test ssing spiked sediment Guideline dated September 2006 with analytical confirmation of test substance concentrations. There were no guideline deviations. Oligochaetes (Lumbriculus) were added to exposure chambers with formulated sediment as recommended in OECD Guideline 218. The sediment-water mixtures were allowed to acclimate for approximately 48 hours prior to the introduction of the test organisms. At test initiation the overlying water in all test chambers appeared slightly cloudy and tan. At test termination the overlying water in all test chambers appeared slightly cloudy and tan. Aside from a few observations of organisms on the surface of the sediment or climbing the walls of the test chambers in all treatment groups and controls, the organisms generally appeared normal and healthy throughout the study except in the 4.00 and 8.0 mg CMIT/MIT/kg dry weight group which had some mortalities. 28d NOEC (survival) = 0.27 mg a.s./kg dry weight.