thiacloprid (ISO);(Z)-3-(6-chloro-3-pyridylmethyl)-1,3-thiazolidin-2-ylidenecyanamide;{(2Z)-3-[(6-chloropyridin-3-yl)methyl]-1,3-thiazolidin-2-ylidene}cyanamide

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

fish early-life stage toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 Feb - 23 May 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 210 (Fish, Early-Life Stage Toxicity Test)

Version / remarks:

1992

Deviations:

yes

Remarks:

Typical minimum mean total length in control fish at test end was below 40 mm recommended by OECD 210. This is not considered to affect the sensitivity of the test since all validity criteria are met.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control), 0 (solvent control, 1122, 243, 486, 972, 1940 and 3890 µg/L
- Sampling method: Samples of test solution were collected from mid-depth in the aquariaon days -1, 0, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91 and 97 from alternating replicate test chambers
- Sample storage conditions before analysis: Samples were analyzed within 24 hours after they were received. The samples were stored in a refrigerator until they were analyzed.

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Five series of stock solutions of test item in the solvent carrier 1-Methyl-2-pyrrolidon (NMP) were prepared on a weight-to-volume basis in 1000 mL.
- Differential loading: no
- Controls: control: dilution water only, solvent control: dilution water and 100 µL/L
- Chemical name of vehicle: 1-Methyl-2-pyrrolidon (NMP)
- Concentration of vehicle in test medium: stock solution: 100%, final test solutions: 100 µL/L, control: 0%, solvent control: 100 µL/L
- Test concentration separation factor: 2

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Source: Forellenzucht Dr.vet.med. Rosengarten, Oesede, Germany (unfertilized rainbow trout eggs and milt on February 15, 1995) and delivered directly to the testing facility)

METHOD FOR PREPARATION AND COLLECTION OF FERTILIZED EGGS
- Numbers of parental fish: 3 female and 3 male adult brood fish
- Method of collection of fertilised eggs: not reported
- Subsequent handling of eggs: acclimated from 9 °C to a temperature of 10 °C over a period of 60 minutes. Eggs were transferred to dry stainless steel bowl and milt was mixed with the eggs (with autoclaved goose
feather) for about 2 minutes. Milt, transported in a separate plastic bag, was examinated under the microscope. There were no negative findings. Dilution water (10° ± 1°C) was added until the eggs were covered. Eggs and milt were stirred for about 10 seconds to facilitate fertilization. After stirring and a waiting period of about 3 minutes without stirring eggs were gently rinsed with 10° ± 1°C dilution water until the milt was no longer
visible in the rinse water. The eggs were allowed to water harden for approximately 2 hours before random distributionto incubation cups in the test system.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

97 d

Hardness:

2.4 - 3.0 °dH

Test temperature:

9.2 - 11.1 °C

pH:

7.1 - 7.5

Dissolved oxygen:

91 - 101 %

Conductivity:

78 - 100 µS/cm

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 0 (solvent control, 1122, 243, 486, 972, 1940 and 3890 µg a.i./L
Mean measured concentrations: < LOD (control), < LOD (solvent control), 122, 244, 483, 918, 1910, and 3910 µg a.i./L

Details on test conditions:

TEST SYSTEM
- Emybro cups: 8 cm diameter teflon pipes with stainless steel plates perforated with holes (hole diameter: 1.8 mm) on the bottom
- Test vessel: aquaria
- Type (delete if not applicable): covered with stainless steel screens
- Material, size, fill volume: glass, 14 x 9 cm, 2.2 L (used for egg hatching); glass, 18 x 22 cm, 7.5 L (growth chambers for the post hatch phase)
- Type of flow-through: diluter system with two programmed Microlab Hamilton MT 4-fold syringe pumps was used for the intermittent introduction of 1,5 mL/h (volumes of 25 µL each 60 seconds) of stock solutions with different concentrations. Flow-splitting cells divided the water streams after the introduction of stock solution and after passing mixing chambers into four aliquots per test concentration before being delivered to replicate test chambers.
- Renewal rate of test solution: 135 L/h splitted in 9 separate water streams of 15 L/h
- No. of fertilized eggs/embryos per vessel: 35 embryos per incubation cup
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water prepared by adding salt stock solutions to demineralized water (Ca++: 0.384 mmole/L, Mg++: 0.096 mmole/L, Na+: 0.148 mmole/L, K+: 0.015 mmole/L, Cl-:0.783 mmole/L, HCO3-: 0.148 mmole/L, SO4-: 0.096 mmole/L)
- Intervals of water quality measurement: temperature: daily, dissolved oxygen and pH and hardness: on day 0, 5, 14, 21, 28, 35, 41, 48, 55, 62, 69, 76, 83, 90 and 97

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16:8 h / light:dark
- Light intensity: 435 lux

EFFECT PARAMETERS MEASURED: fry survival (day 69 and 97), egg hatchability (day 38), time to hatch (from day 32 to 37), swimming up (from day 50 to 58), fry growth (day 69 and 97), egg viability (13 days after fertilization), morphological and behavioral effects (post-hatch period)

VEHICLE CONTROL PERFORMED: yes

RANGE-FINDING STUDY
- Test concentrations: 0.4, 1.32, 4.0, and 12.0 mg/L
- Results used to determine the conditions for the definitive study: NOEC (49 d) < 400 µg/L

POST-HATCH DETAILS
- Begin of post-hatch period: after 95 percent of all living eggs in the control had hatched (study Day 35, post hatch Day 0).
- No. of hatched eggs (alevins)/treatment released to the test chamber: 15
- Release of alevins from incubation cups to test chamber on day no.: 42 (post-hatch day 7)

FERTILIZATION SUCCESS STUDY
- Number of eggs used: 50
- Removal of eggs to check the embryonic development on day no.: 13

Reference substance (positive control):

no

Duration:

97 d

Dose descriptor:

NOEC

Effect conc.:

244 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

weight

Details on results:

- Mortality/survival at embryo, larval, juvenile, and adult stages:
day 69: control (100 %), solvent control (100 %), 122 µg a.i./L (97 %), 244 µg a.i./L (97 %), 483 µg a.i./L (100 %), 918 µg a.i./L (95 %), 1910 µg a.i./L (98 %) and 3910 µg a.i./L (97 %)
day 97: control (98 %), solvent control (97 %), 122 µg a.i./L (95 %), 244 µg a.i./L (97 %), 483 µg a.i./L (100 %), 918 µga.i./L (95 %), 1910 µg a.i./L (98 %) and 3910 µg a.i./L (97 %)
- Numbers hatched: control (96 %), solvent control (94 %), 122 µg a.i./L (89 %), 244 µg a.i./L (87%), 483 µg a.i./L (93 %), 918 µg a.i./L (91 %), 1910 µg a.i./L (89 %) and 3910 µg a.i./L (97 %)
- Observations on body length and weight of young and/or exposed parents at one or more time periods: length (day 97): significant effect in the 1910 and 3910 µg a.i./L test levels, weight (day 97): significant difference from the pooled controls in 483, 1910, and 3910 µg a.i./L test levels
- Data for length and weight of surviving fish: control mean length (post-hatch day 62): 31 mm, solvent control mean length (post-hatch day 62): 31 mm (lower than the recommended typical minimum mean total length of 40 mm recommended by OECD 210)
- Other biological observations: no compound related effects in all cases except in case of darkened coloration and quiescence. In case of darkened coloration and in case of quiescence there were a dose response from post-hatch day 20 to post-hatch day 57 in the highest test level of 3910 µg a.i./L.
- Effect concentrations exceeding solubility of substance in test medium: no
- Incidents in the course of the test which might have influenced the results: no

Reported statistics and error estimates:

Data were statistically analysed by using a PC based computer program developed by WEST, Inc. & D.G. Gulley (1994) with conclusions of statistical significance based on a 95 percent confidence level α =0.05.

Table 1: Analytical results

Nominal concentrations in mg/L	Mean measured concentration in mg/L	Percent of nominal
Control	< 0.001	-
Solvent control	< 0.001	-
0.122	0.122	100
0.243	0.244	100
0.486	0.483	99
0.972	0.918	94
1.940	1.910	98
3.890	3.910	101

Table 2: Summary on survival of rainbow trout:

Mean measured conc. [mg/L]	% larvae survival at hatch on day 38	% survival after hatch on day 69	% survival after hatch on day 97
	Mean	Mean	Mean
Control	96	100	98
Solvent control	94	100	97
0.122	89	97	95
0.244	87	97	97
0.483	93	100	100
0.918	91	95	95
1.910	89	98	98
3.910	97	97	97

Table 3: Standard Length and Wet Weight of Rainbow Trout (Oncorhvnchus mykiss)
Exposed to the test item in an Early Life-Stage Toxicitv Study

Nominal concentration [mg/L]	Replicate	Post-hatch day 34	Post-hatch day 62
		Length [mm]	Length [mm]	Wet weight [mg]	Dry weight [mg]
Control	A	27	31	329	53
	B	27	31	380	62
	C	26	30	306	50
	D	27	31	326	54
	Mean	27	31	335	55
Solvent control	A	28	32	354	60
	B	27	32	345	58
	C	27	31	325	53
	D	26	30	300	48
	Mean	27	31	331	55
122	A	26	30	-	46
	B	27	31	-	52
	C	26	30	-	48
	D	26	31	-	50
	Mean	26	31	-	49
244	A	27	31	-	53
	B	27	31	-	56
	C	26	30	-	57
	D	26	30	-	52
	Mean	27	31	-	52
483	A	26	31	-	50
	B	26	31	-	50
	C	26	30	-	43
	D	26	29	-	45
	Mean	26*	30	-	47**
918	A	27	31	-	59
	B	26	31	-	59
	C	26	30	-	47
	D	26	29	-	45
	Mean	26*	30	-	53
1910	A	26	30	-	49
	B	26	30	-	48
	C	26	29	-	42
	D	25	29	-	43
	Mean	26*	30*	-	46*/**
3910	A	26	30	-	46
	B	25	29	-	47
	C	25	28	-	38
	D	25	28	-	42
	Mean	25*	29*	-	43*/**

* Denotes statistically significant difference [WILLIAMS TEST] from pooled controls (α = 0.05)

** Denotes statistically significant difference [BONFERRONI t-TEST] from pooled controls (α = 0.05).

Table 4: Summary of endpoints

Biological endpoint	NOEC [mg/L]	LOEC [mg/L]
Survival
At hatch	≥ 3.910	> 3.910
% survival after hatch on day 69	0.483	0.918
% survival after hatch on day 97	≥ 3.910	> 3.910
Growth at the end of the test
Total length at day 69	0.244	0.483
Total length at day 97	0.918	1.910
Dry weight at day 97	0.244	0.483
Other observed effects
Time to hatch at day 37	≥ 3.910	> 3.910
Time to swim-up at day 55	1910	3910
Morhpological and behavioural effects from post-hatch day 20 to post-hatch day 57	1.910	3.910

Table 5: Validity criteria for OECD 210

Criterion from the guideline	Outcome	Validity criterion fulfilled
The dissolved oxygen concentration should be >60% of the air saturation value throughout the test.	91 - 101%	yes
The water temperature should not differ by more than ± 1.5 °C between test chambers or between successive days at any time during the test, and should be within the temperature ranges specified for the test species (10 ± 1.5°C).	9.2 - 11.1 °C (overall test period)	Not determinable, since only the overall test period range was reported. However, overall test period temperature range was within the recommended range for the test species and only 0.3 °C higher than the difference   recommended for   test chambers or successive days temperature diffenerences. Since all biological validity criteria were met, this validity criterion is considered met.
The analytical measure of the test concentrations is compulsory.	Analytical measurements performed	yes
Overall survival of fertilised eggs and post-hatch success in the controls and, where relevant, in the solvent controls should be ≥ 75% .	Mean egg viability = 80% Fry survival = 97-98%	yes

Validity criteria fulfilled:

yes

Remarks:

For further, details, please refer to 'Any other information on results incl. tables'.

Conclusions:

The lowest NOEC (97 d) was determined to be 0.24 mg a.i./L, based on the most sensitive endpoints in rainbow trout (Oncorhynchus mykiss) in a 97-day fish early life stage test.

Reference 2

Endpoint:

fish early-life stage toxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

17 Mar -19 Apr 1999

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 (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control), 10, 20, 40, 80 and 160 µg a.i./L
- Sampling method: samples were taken (one alternating replicate) using a volumetric pipet on test day 0, 5 and weekly thereafter including day 33

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Stock solutions with a nominal concentration of 46 µg/mL were prepared daily (e.g., by dissolving 0.094 g (0.0912 g as active ingredient) test item in 2000 mL of NANOpure* water.
- Differential loading: no
- Controls: dilution water only
- Test concentration separation factor: 2

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: fathead minnow
- Source: laboratory culture since 20 years

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

33 d

Test temperature:

25 - 26 °C

pH:

6.8 - 8.0

Dissolved oxygen:

6.1 - 8.9 mg/L

Conductivity:

170 µmhos/cm

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 10, 20, 40, 80 and 160 µg a.i./L
Mean measured concentrations: < LOQ, 11, 21, 44, 93 and 170 µg a.i./L

Details on test conditions:

TEST SYSTEM
- Emybro cups: glass jars (5-cm O.D., 8-cm high) with 475u-mesh opening Nitex® screen bottoms
- Test vessel: Aquaria
- Material, size, fill volume: glass, 39 x 20 x 25 cm, 15 L
- Type of flow-through: intermittent-flow proportional diluter
- Renewal rate of test solution (frequency/flow rate): 6.3 aquarium volumes/24 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
- Biomass loading rate:

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: well water which was pumped into an epoxy-coated concrete reservoir where it was supplemented on demand with untreated Town of Wareham well water and aerated.
- Alkalinity: 28 - 31 mg/L
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16:8 h light:dark
- Light intensity: 100 footcandles

EFFECT PARAMETERS MEASURED: larval survival at hatch (day 4), larval survival (daily until test day 3, afterwards twice weekly), total length, wet weight and dry weight (test end)

POST-HATCH DETAILS
- Begin of post-hatch period: day 3
- No. of hatched eggs (alevins)/treatment released to the test chamber: 40
- Release of alevins from incubation cups to test chamber on day no.: 4

Reference substance (positive control):

no

Duration:

33 d

Dose descriptor:

NOEC

Effect conc.:

>= 170 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

other: hatchability, survival and larval growth (length, wet weight and dry weight)

Details on results:

No statistical effects on hatchability, survival and larval growth (length, wet weight and dry weight) were evident in any of the treatment levels tested.

Table 1: Validity criteria for OECD 210

Criterion from the guideline	Outcome	Validity criterion fulfilled
The dissolved oxygen concentration should be >60% of the air saturation value throughout the test.	93 -97 %	yes
The water temperature should not differ by more than ± 1.5 °C between test chambers or between successive days at any time during the test, and should be within the temperature ranges specified for the test species (Annex 2).	25°C - 26 °C	yes
The analytical measure of the test concentrations is compulsory.	Atalytical measurement was perforemed	yes
Overall survival of fertilised eggs and post-hatch success in the controls and, where relevant, in the solvent controls should be greater than or equal to 75%	Overall survival: 77% Post-hatch success: 91%	yes

Validity criteria fulfilled:

yes

Remarks:

For further, details, please refer to 'Any other information on results incl. tables'.

Conclusions:

The NOEC (33 d) was ≥ 170 µg a.i./L (mean measured) in a fish early life-stage study with fathead minnow (Pimephales promelas)

Reference 3

Endpoint:

fish life cycle toxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

02 Jul 1998 - 19 Mar 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 72-5 (Fish Life Cycle Toxicity)

Version / remarks:

1986

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control), 0.10, 0.20, 0.40, 0.80 and 1.60 mg a.i./L and stock solutions
- Sampling method: samples were taken (one alternating replicate) weekly (minimum)

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Stock solutions with a nominal concentration of 45 µg/mL were prepared daily (e.g., by dissolving 1.4808 g (1.436 g as active ingredient) test item in a total volume of 32 L of dilution water)
- Differential loading: no
- Controls: dilution water only
- Test concentration separation factor: 2

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: fathead minnow
- Source: laboratory culture since 20 years

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

260 d

Hardness:

39 - 42 mg/L as CaCO3 (treatment group mean values)

Test temperature:

25 °C (mean value per treatment group)

pH:

6.4 - 7.7

Dissolved oxygen:

7.2 mg/L (mean value per treatment group)

Conductivity:

160 - 170 µmhos/cm (treatment group mean value range)

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 0.10, 0.20, 0.40, 0.80 and 1.60 mg a.i./L
Mean measured concentrations: < LOQ (control), 0.10, 0.20, 0.43, 0.78, and 1.6 mg a.i./L

Details on test conditions:

TEST SYSTEM
- Emybro cups(type/material, size): glass, 5 cm diameter
- Test vessel: aquaria
- Material, size, fill volume: glass with silicone sealant seams, 60 cm x 30 cm x 30 cm, 27 L
- Type of flow-through: intermittent-flow proportional diluter
- Renewal rate of test solution (frequency/flow rate): 1000 ml per cycle of test solution to each duplicate aquarium at a rate of approximately 210 cycles per 24 hours / 7.8 volume replacements/day (pre-spawning phase) and 500 ml per cycle of test solution to replicate aquaria (4) at a rate of approximately 419 cycles per 24 hours / 7.8 volume replacements/day (spawning phase)
- No. of fertilized eggs/embryos per vessel: 100 (50 per embryo cup)
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): 2
- Biomass loading rate:

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: drawn from a 125-meter deep bedrock well
- Alkalinity: 25 - 45 mg/L as CaCO3
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: daylength: 10:45 - 15:00 h (based on dusk to dawn times in Evansville, USA)
- Light intensity: 39 to 80 footcandles (flourescent light)

EFFECT PARAMETERS MEASURED: F0 time to hatch, F0 hatching success, F0 30-day survival, F0 30-day total length, F0 59-day survival, F0 59-day total length, F0 59-day wet weight, F0 termination survival, F0 termination male total length, F0 termination female total length, F0 termination male wet weight, F0 termination female wet weight, F0 eggs/spawn, F0 spawns/female, F0 eggs/female, F1 time to hatch, F1 hatching success, F1 30-day survival, F1 30-day total length,F1 30-day wet weight

VEHICLE CONTROL PERFORMED: no

POST-HATCH DETAILS
- Begin of post-hatch period: 5 days
- No. of hatched eggs (alevins)/treatment released to the test chamber: 50 (25/replicate)
- Release of alevins from incubation cups to test chamber on day no.: 4

Reference substance (positive control):

no

Duration:

260 d

Dose descriptor:

NOEC

Effect conc.:

0.78 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

other: F0 male total length and wet weight

Results with reference substance (positive control):

No adverse effects on the hatching success or survival of F0 fathead minnow was observed during a complete life-cycle exposure concentrations up to and including 1.6 mg a.i./L.

Validity criteria fulfilled:

not applicable

Conclusions:

The NOEC (260 d) was determined to be 0.78 mg a.i./L based on male total length and wet weight in a fish life cycle toxicity study with Fathead minnows (Pimephales promelas).

Reference 4

Endpoint:

long-term toxicity to fish, other

Remarks:

Maturation study

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

05 May - 19 Aug 1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: 47 day old fathead minnows (Pimephales promelas) were exposed to the test substance under flow-through conditions for 106 days.
- Parameters analysed / observed: (Sexual) maturation and development

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control), 3.5, 6.9, 13.8, 27.5, 55, 110 and 650 µg/L (one alternating replicate)
- Sampling method: samples were taken weekly

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Each diluter stock solution (123 mg/L) was prepared by dissolving approximately 2.0944 g of test item (adjusted for purity) in 17 L of water at room temperature. The stock solution was used to dose
the test aquaria with the test item via a proportional diluter system
- Differential loading: no
- Controls: dilution water only
- Test concentration separation factor: 2

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: fathead minnows
- Lot no: ABS042099
- Source: Aquatic Biosystems, Fort Collins, USA
- Age at study initiation: 42- 43 d

FEEDING DURING TEST
- Food type: newly hatched brine shrimp and/or a commercial fish food (Tetramin® or trout chow)
- Frequency: daily

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

106 d

Test temperature:

23.5 - 27.1 °C

pH:

7.3 - 7.9

Dissolved oxygen:

5.1 - 8.0 mg/L

Conductivity:

101 - 119 µmhos/cm

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 3.5, 6.9, 13.8, 27.5, 55, 110 and 650 µg a.i./L
Mean measured concentrations: < 0.63 (control), 3.83, 7.58, 14.6, 29.8, 58.5, 116, and 710 µg a.i./L

Details on test conditions:

TEST SYSTEM
- Test vessel: 39.7-L aquaria
- Material, size, headspace, fill volume: glass, 30.5 x 52 x 30.5 cm,
- Type of flow-through: glass two-liter Mount-Brungs proportional diluter system with a Hamilton Model 420 dual syringe pump
- Renewal rate of test solution (frequency/flow rate):
- No. of organisms per vessel: 25
- 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: spring water blended with reverse osmosis water to produce soft (40 to 60 mg/L) water. The spring water is collected from a spring box, passed through a multimedia filter, a 5
micron bag filter, granular activated carbon filters, a 1 micron cartridge filter and finally an ultraviolet sterilizer. This is then blended with city water that has been dechlorinated with sodium metabisulfite, passed through a multimedia filter, granular activated carbon units, demineralized by conventional softeners, passed through a 5 micron cartridge filter, and treated by double pass reverse osmosis.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Light intensity: 69.3 foot-candles (745.6 lux)

EFFECT PARAMETERS MEASURED: abnormal behaviour, abnormal physical changes, mortality and maturation (appearance of tubercles on snout, vertical stripe coloration pattern, dark spot on dorsal fin, thickening of the dorsal ridge, general body shape of a male/female (blunt head, abdomen not distended), sex (definitive/probable male/female / unknown sex), presence of ovipositor

Reference substance (positive control):

no

Duration:

106 d

Dose descriptor:

NOEC

Effect conc.:

>= 710 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

other: abnormal behaviour, abnormal physical changes, mortality and maturation

Details on results:

The number of fish per test level at study initiation was 50. The number of surviving fish in each group being 48, 49, 48, 46, 49, 49, 49 and 49 for the control, 3.83,7.58, 14.6, 29.8,58.5,116 and 710 µg a.i./L.
No physical signs of maturation (tubercle development, dark spot on dorsal fin, striped coloration pattern, or ovipositor development), nor the timing of the onset of these physical signs, was different between the treatment groups and the control.

Validity criteria fulfilled:

not applicable

Conclusions:

The NOEC (106 d) was ≥ 710 µg a.i./L (mean measured) in a maturation study with fathead minnow Pimephales promelas.

Description of key information

Fish: NOEC (96 d) = 244 µg/L (mean measured, OECD 210, Oncorhynchus mykiss)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

NOEC

Effect concentration:

244 µg/L

Additional information

Four experimental GLP studies are available testing the chronic toxicity of 3-(2-chlor-5-pyridyl-methyl)-cyanimino-1,3-thiazolidin towards fish. The key study was performed with rainbow trout Oncorhynchus mykiss and the three supporting studies tested the effects of the test substance on fathead minnow Pimephales promelas.

The key freshwater study was a 97-day fish early life stage, flow-through study performed according to OECD 210. Rainbow trout (O. mykiss) eggs were exposed to test item nominal concentrations of 0.122, 0.243, 0.486, 0.972, 1.94 and 3.98 mg/L. A solvent (1-methyl-2-pyrrolidon) control was also included. Mean measured concentrations during the test were 0.122, 0.244, 0.483, 0.918, 1.91 and 3.91 mg a.i./L (94-101 % of nominal concentrations). The most sensitive endpoint was fry dry weight. On day 97, analysis of data showed a significant difference from the pooled controls in mean measured concentrations of 483, 1910, and 3910 µg a.i./L. The NOEC (97 d) was therefore determined to be 0.244 µg/L (mean measured).

This result is supported by further freshwater studies with P. promelas. In the first supporting study, fathead minnows were continuously exposed to five concentrations of the test item (and a dilution water control) for a complete life-cycle (260 days) according to EPA OPP 72-5. Based on the test item analyses, the mean measured exposure concentrations of thiacloprid were defined as 0.10, 0.20, 0.43, 0.78, and 1.6 mg a.i./L, which ranged from 98 - 108 % of the nominal concentrations. The NOEC (260 d) was determined to be 0.78 mg a.i./L based on male total length and wet weight.

The second study with P. Promelas assessed potential effects of the test item on the survival and sexual maturation of fish. The experimental was not performed according to a specific guideline. 47 day old fathead minnows were exposed to a nominal concentration range between 3.5 and 650 µg a.i./L. Maturation and development were monitored for 106 days. Mean measured concentrations were found to be in a range of 3.83 and 710 µg a.i./L, representing 105.1 to 109.9 % of nominal concentrations. No physical signs of maturation (tubercle development, dark spot on dorsal fin, striped coloration pattern, or ovipositor development), nor the timing of the onset of these physical signs, was different between the treatment groups and the control. The NOEC (106 d) was therefore ≥ 710 µg a.i./L (mean measured).

The third supporting study was performed according to EPA OPP 72-4. Fathead minnow embryos and larvae were exposed to for 33 days to the nominal concentrations of 10, 20, 40, 80 and 160 µg a.i./L under flow-through conditions. Measured concentrations were in the range of 100 - 120 % of nominal concentrations. No statistical effects on hatchability, survival and larval growth (length, wet weight and dry weight) were evident in any of the treatment levels tested. The NOEC (33 d) was therefore ≥ 170 µg a.i./L (mean measured).