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

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-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:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPP 72-4 (Fish Early Life-Stage and Aquatic Invertebrate Life-Cycle Studies)

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™ 886
- Physical state: Amber liquid
- Stability under test conditions: stable at room temperature

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. 24088

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: Insoluble material was not observed in any test vessels during the test
- 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: No
- Preliminary purification step (if any): No
- Final dilution of a dissolved solid, stock liquid or gel: 0.03, 0.05, 0.08, 0.12, and 0.20 mg a.i./L

OTHER SPECIFICS: Purity of test material was 14.17%

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.03, 0.05, 0.08, 0.12, and 0.20 mg a.i./L on days 0, 7, 14 and 21
- Sampling method: Samples were stored in 40 mL glass bottles and transferred immediately to the analytical laboratory
- Sample storage conditions before analysis: Samples were stored at 2-4 ºC for 72 hours or less prior to analysis

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Dispersion
- Controls: Negative control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Water
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): Not applicable
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): No

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain/clone: Daphnia magna
- Source: In-house culture
- Age of parental stock (mean and range, SD): Less than 24 h old at test initiation
- Feeding during test: Yes, yeast/trout chow suspension and Selenastrum capricornutum.
- Food type: Yeast/trout chow suspension and Selenastrum capricornutum
- Amount: Ad libitum
- Frequency: 2 times per day

Study design

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

n/a

Test conditions

Hardness:

172 to 180 mg/L as CaCO3

Test temperature:

19.6 +/- 0.6 °C

pH:

8.3 +/- 0.1

Dissolved oxygen:

> 75 % saturation (8.7 +/- 0.4)

Salinity:

Not applicable

Conductivity:

1100 +/- 100 µmhos/cm

Nominal and measured concentrations:

Nominal (mg CMIT/MIT per liter): 0, 0.03, 0.05, 0.08, 0.12, and 0.20
Mean measured (mg CMIT/MIT per liter): 0, 0.02, 0.04, 0.06, 0.10 and 0.18

Details on test conditions:

TEST SYSTEM
- Test vessel: Flow-through
- Renewal of test solution: 24.6 media exchanges per 24 h in each test vessel
- Volume of test vessels: 270 mL
- Volume/animal: 27 mL
- Number of animals/vessel: 10
- Number of vessels/ concentration: 4
- Test performed in closed vessels due to significant volatility of TS: No

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Well water collected at EnviroSystems, Hampton, New Hampshire, USA
- Alkalinity: 155 to 175 mg/L as CaCO3
- Hardness: 172 to 180 mg/L as CaCO3

OTHER TEST CONDITIONS
- Photoperiod: 16 h light :8 h dark with 15 minute transition periods.
- Light intensity: 8 Es-1m-2

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Effect concentrations 2

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 0.18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- Behavioural abnormalities: No
- Observations on body length and weight: No
- Other biological observations: No
- Mortality of control: 2.5% after 21 days
- Other adverse effects control: No
- Abnormal responses: No
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: Mean measured concentrations of the TS were in agreement with nominal concentrations of active ingredient. Insoluble material was not observed in any test vessels during the test.
- Effect concentrations exceeding solubility of substance in test medium: No

Results with reference substance (positive control):

a

Reported statistics and error estimates:

Results of the toxicity test were interpreted by standard statistical techniques (US EPA, 1988b, Short-term methods for estimating the chronic toxicity of effluents and receiving waters to marine and estuarine organisms. Environmental Monitoring and Support Laboratory, Cincinnati, Ohio, USA, EPA/600/4-87/028), when warranted. Shapiro-Wilk’s test was used to determine if data were normally distributed, and Bartlett’s test was used to determine if variances were homogeneous. Since the assumption of homogeneity of variance was met for all data analyzed, a parametric ANOVA followed by Dunnett’s test was used to compare control to treatment means. Dichotomous data were transformed (arc sin square root) prior to statistical analysis. All calculations were performed using mean measured concentrations of the active ingredient.

Any other information on results incl. tables

 Effect data

Mean measured concentration (mg CMIT/MIT per liter)	% survival at 21 days	Total number of young produced	Day of first brood	Mean young per surviving female	Average dry weight of surviving adults (mg)
0 (control)	97.5	989	9	102	0.60
0.02	92.5	993	9	108	0.64
0.04	92.5	968	9	106	0.67
0.06	87.5	1015	9	116	0.66
0.10	82.5	1177	9	144	0.66
0.18	62.5 *	898	9	148	0.73

* statistically different from control

 

Biological endpoint	NOEL	LOEL	MATC	EC50
	(mg CMIT/MIT per liter)
First generation survival	0.10	0.18	0.13	>0.18
Time to first brood	0.18	>0.18	>0.18	--
Number of young produced 1.     total per replicate 2.     mean per surviving female	0.18 0.18	>0.18 >0.18	>0.18 >0.18	--
Dry weight of first generation	0.18	>0.18	>0.18	--

 

   Validity criteria for invertebrate reproduction test according

	Fulfilled	Not fullfilled
Mortality of parent animals < 20 % at test termination	yes
Mean number of live offspring produced per parent animal surviving at test termination³60	Yes

 

 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The results are based on mean measured concentrations:
21d-NOEC = 0.10 mg a.s./l;
21d-LC50 > 0.18 mg a.s./l.

Executive summary:

US EPA FIFRA 72- 4, Aquatic invertebrate life- cycle studies with analytical confirmation of TS concentrations. Insoluble material was not observed in any test vessels during the test. Mean measured concentrations of the TS were in agreement with nominal concentrations of active ingredient. Loading rate during the toxicity test was approximately 0.024 g/L at any time and 0.001 g/L/ 24 hours. Water quality parameters were within acceptable limits throughout the test. The percentage of surviving adults was statistically significantly reduced in comparison to the control at 0.18 mg CMIT/MIT per liter. The total number of young producted and the mean number of young per surviving female was not significantly lower than the control at any tested concentration. The average dry weight of surviving adult daphnids was not lower than the control at any concentration and the time to first brood was identical for all concentrations of TS. No sublethal effects were noted during the test.  The most sensitive biological endpoint was survival of first generation daphnids