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

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28 Mar - 28 Apr 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 235 (Chironomus sp., Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control), 1.00, 2.20, 4.80, 10.6, 23.4 and 51.5 µg a.i./L
- Sampling method: Samples were taken from freshly prepared test levels for day 0 (including control(s)), and in all aged test levels on day 2 (contents of all six replicate vessels combined) at the end of exposure period.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Stock solution S1 was prepapared by adding 10.2 mg to 1000 mL test medium and ultra-sonicating for 20 minutes and and well agitating on a magnetic stirrer for 40 minutes. From this stock solution 25 mL were added to 500 mL test medium to yield stock solution (S2) and well agitated on a magnetic stirrer for 5 minutes. From stock solution (S2) dilution series wereprepared by adding appropriate aliquots of this stock solution to the test medium to yield the nominal test concentrations.
- Differential loading: no
- Controls: dilution water only
- Test concentration separation factor: 2.2

Test organisms (species):

Chironomus riparius

Details on test organisms:

TEST ORGANISM
- Common name: harlequin fly
- Age at study initiation: 2 - 3 days after hatching
- Stage and instar at study initiation: 1st instar larvae
- Method of breeding: kept in cages (40 x 40 x 40 cm), with a gauze on each side of the cage. A basin is set on the bottom of each cage. The bottom of the basins are covered with a thin layer of "Kieselgur" (silica) and a 4 - 5 cm high layer of reconstituted water according to Elendt medium (M7), which is aerated gently. To start a culture in the cage, 2 - 4 egg masses are placed into the prepared basin. The hatched larvae are fed
with green algae and an aqueous suspension of a plant material based fish food (Tetra Phyll®). After 2 to 3 weeks the adults emerge. After mating, female adults will lay egg masses on the water surface where these can be taken to start a new culture or to perform toxicity tests. The culture conditions are 20 ± 2 °C and 16 to 8 hours light-darkcycle (light intensity ca. 500 - 1000 lux).
- Source: Orininally obtained from University of Frankfurt am Main (Germany) and kept in testing facility laboratory since then.


METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES, INCLUDING CULTURING CONDITIONS: First instar larvae were obtained from culture egg masses 2 - 3 days after hatching.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

19.8 - 20.4 °C

pH:

7.8

Dissolved oxygen:

8.3 - 8.4 mg/L

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 1.00, 2.20, 4.80, 10.6, 23.4 and 51.5 µg a.i./L
Mean measured concentrations: (control), 0.981, 2.17, 4.78, 10.5, 22.7 and 51.2 µg a.i./L

Details on test conditions:

TEST SYSTEM
- Test vessel: 20 mL beakers
- Material, headspace, fill volume: glass, 10 mL, 10 mL
- Volume of solution: 10 mL
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt medium (M7), based on deionised water
- Culture medium different from test medium: no
- Intervals of water quality measurement: temperature, pH and oxygen in in all test concentrations and the control and at the beginning (day 0, before inserting the larvae) and at end of the exposure period (day 2) in the combined six test vessels of each test concentration and the control)

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16:8 h light:dark
- Light intensity: 500 - 1000 lux

EFFECT PARAMETERS MEASURED: immobilisation (animals showing no swimming movements within 15 seconds after slight agitation of the vessel) after 24 and 48 hours

RANGE-FINDING STUDY
- Test concentrations: 0 (control), 0 (solvent control (0.1 mL dimethylformamide/L)), 0.001, 0.005, 0.01, 0.05 and 0.10 mL/L
- Results used to determine the conditions for the definitive study: immobilisation after 48 hours: 5 - 5 – 15 – 30 - 100 and 100 % (EC50 (48 h) = 0.001 - 0.05 mg/L)

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

10.77 µg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks on result:

other: 95%-confidence limits: 5.29 - 17.5 µg a.i./L

Details on results:

- Immobilisation of control: 3.3%

Reported statistics and error estimates:

EC50 values and confidence intervals were calculated for the stated exposure period, using TOXRAT Solutions GmbH (2009)

Table 1:Acute toxicity of test item to first instar-larvae of Chironomus riparius after 48 hours (based on nominal concentrations)

Test concentration [µg a.i./L]	Exposed chironomids (=100%)	Immobility
		24 h		48 h
		n	%	n	%
control	30	0	0	1	3.3
1.00	30	0	0	2	6.7
2.20	30	2	6.7	3	10.0
4.80	30	3	10.0	6	20.0
10.6	30	3	10.0	10	33.3*
23.4	30	7	23.3*	30	100.0*
51.5	30	29	96.7*	30	100.0*

* statistically different to control

Table 2: Nominal and measured concentrations of active substance

Nominal concentrations [µg a.s./L]	Day 0		Day 2
	Analysed conc. mean of two analyses each [µg a.i./L]	Percent of nominal	Analysed conc. mean of two analyses each [µg a.i./L]	Percent of nominal
control	< 0.100	-	< 0.100	-
1.00	0.980	98.0	0.981	98.1
2.20	2.14	97.3	2.19	99.5
4.80	4.67	97.3	4.76	99.2
10.60	10.3	97.2	10.6	100.0
23.40	22.4	95.7	22.9	97.9
51.50	50.3	97.7	52.1	101.2
Average		97.2		99.3

Table 3: Statistical results of probit analysis conducted for determination of EC50 values (based on nominal concentrations): 

Probit analysis for data obtained after:	NOEC µg a.i./L (nominal)	EC50 µg a.i./L (nominal)	lower 95% cl µg a.i./L (nominal)	upper 95% cl µg a.i./L (nominal)
24 hours	10.6	26.1	7.46	61.0
48 hours	4.80	10.8	5.29	17.5

Table 4: Validity criteria for OECD 235 (2011)

Criterion from the guideline	Outcome	Validity criterion fulfilled
In the control, including the solvent control, not more than 15% of the larvae should show immobilisation.	3.3%	yes
The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in control and test vessels.	8.3 mg/L	yes

Validity criteria fulfilled:

yes

Remarks:

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

Conclusions:

The EC50 (48 h) for Chironomus riparius was determined to be 10.77 µg a.i./L (nominal) under static conditions.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

15 - 19 Mar 1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 72-3 (Estuarine/Marine Fish, Mollusk, or Shrimp Acute Toxicity Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Americamysis bahia (previous name: Mysidopsis bahia)

Details on test organisms:

Mysids used in the test were obtained as juveniles (<24 hours old) from cultures maintained by the testing facility.

Test type:

flow-through

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Nominal and measured concentrations:

Nominal concentrations: 5.8, 9.7, 16, 27, 45 and 75 µg a.i./L
Mean measured concentrations: < LOQ, 6.1, 11, 17, 29, 50 and 78 µg a.i./L

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

31 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

mortality

Validity criteria fulfilled:

not applicable

Conclusions:

In a 96-hour flow-through acute toxicity test with the saltwater mysid (Mysidopsis bahia), the LC50 (96h) was determined to be 0.31 µg a.i./L (mean measured).

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

18 Dec - 22 Dec 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 72-2 (Aquatic Invertebrate Acute Toxicity Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

other: Hyallella azteca

Details on test organisms:

21 - 21 days old species from the laboratory culture.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 6.25, 12.5, 25, 50 and 100 µg a.i./L
Mean measured concentrations: < LOD (control), 6.14, 11.33, 23.57, 45.10, and 90.82 ug a.i./L

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

40.7 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mortality

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

24.5 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

other: sublethal and behavioral effects,

Validity criteria fulfilled:

not applicable

Conclusions:

The LC50 (96 h) of the test item was 40.7 µg a.i./L in an acute toxicity test with Hyalella azteca.

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

07 - 09 Feb 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

1984

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

yes

Remarks:

dimethylformamide (0.1 mL/L)

Test organisms (species):

Daphnia magna

Details on test organisms:

Laboratory kept animals of < 24 h age were used in the study.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 1.0, 3.2, 5.6, 10, 18, 32, 56 and 100 mg a.i./L
Mean measured concentrations: < LOD, 1.05, 3.04, 5.4, 9.1, 16.7, 29.4, 48.3 and 85.1 mg a.i./L

Reference substance (positive control):

yes

Remarks:

K2Cr2O7

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 85.1 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Details on results:

- Effect concentrations exceeding solubility of substance in test medium: At 85.1 mg/L (mean measured) white particles were observed in the water and on the bottom of the test vessels after 24 and 48 hours.

Results with reference substance (positive control):

Effect for EC50 (24 h) value is within the recommended range of 0.6 - 2.1 mg/L: EC50 (24 h) = 1.35 mg/L

Validity criteria fulfilled:

yes

Conclusions:

The EC50 (48 h) of the test item was determined to be > 85.1 mg a.i./L in an acute toxicity study with water flea Daphnia magna.

Reference 5

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

17 Jun - 10 Jul 2002

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

1984

Deviations:

yes

Remarks:

Different test species

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

other aquatic arthropod: Ecdyonurus sp.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 0.004, 0.009, 0.019, 0.041 and 0.09 mg a.i./L
Mean measured concentrations: < LOD (control), 0.003, 0.0076, 0.0171, 0.0377 and 0.084 mg a.i./L

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.008 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks:

and mortality

Remarks on result:

other:

Remarks:

The test organism is no standard test organism for this endpoint. However, as this test revealed the lowest EC50, the results will be used for derivation of PNEC freshwater (intermittent releases).

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

0.024 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Details on results:

Immobility in control: 0%

Validity criteria fulfilled:

yes

Conclusions:

In an acute toxicity study with mayfly Ecdyonurus sp., the LC50 (48 h) of the test item was determined to be 0.0238 mg a.i./L and the EC50 (48 h) for immobility and mortality was 0.0077 mg a.i./L.

Reference 6

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

17 - 19 Jun 2002

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

1984

Deviations:

yes

Remarks:

Different test species

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

other aquatic arthropod: Sericostoma personatum

Details on test organisms:

Field collected caddisflies were maintained in treated mains water at approximately 13.5°C under the test conditions.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 0.001, 0.01 and 0.1 mg a.i./L

Details on test conditions:

range-finding study

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

>= 0.1 - <= 1 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Validity criteria fulfilled:

yes

Conclusions:

The EC50 (48 h) value of the test item for immobility in Sericostoma personatum larvae was observed to be between 0.1 and 1.0 mg/L (nominal) in a static range-finding study.

Reference 7

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

17 - 27 Jun 2002

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

1984

Deviations:

yes

Remarks:

Different test species

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

other aquatic crustacea: Asellus aquaticus

Details on test organisms:

obtained from a breeding colony and maintained in treated mains water at approximately 13.5 °C under the test conditions.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 0.009, 0.019, 0.041, 0.09 and 0.20 mg a.i./L
Mean measured concentrations: < LOD, 0.0084, 0.0177, 0.0387, 0.0837 and 0.1880 mg a.i./L

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.076 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks:

and mortality

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

0.099 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Details on results:

Control mortality: 0%

Validity criteria fulfilled:

yes

Conclusions:

In an acute toxicity study with Asellus aquaticus, the LC50 (48 h) of the test item was determined to be 0.0989 mg a.i./L (nominal) and the EC50 (48 h) for immobility and mortality was 0.0758 mg a.i./L (nominal).

Reference 8

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

17 - 27 Jun 2002

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

1984

Deviations:

yes

Remarks:

Different test species

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Gammarus pulex

Details on test organisms:

Obtained from a breeding colony and kept n treated mains water at approximately 13.5°C under the test conditions.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 0.004, 0.009, 0.019, 0.041, 0.09 and 0.20 mg
Mean measured concentrations: < LOD (control), 0.0035, 0.0083, 0.0185, 0.0386, 0.0822 and 0.1895 mg a.i./L

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.068 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

0.056 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Validity criteria fulfilled:

yes

Conclusions:

In an acute toxicity study with Asellus aquaticus, the LC50 (48 h) of the test item was determined to be 0.056 mg a.i./L (nominal) and the EC50 (48 h) for immobility was 0.068 mg a.i./L (nominal).

Description of key information

EC50 (48 h) = 0.0108 mg/L (nominal, OECD 235, Chironomus riparius)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

10.8 µg/L

Additional information

Eight experimental GLP studies are available testing the acute toxicity of 3-(2-chlor-5-pyridyl-methyl)-cyanimino-1,3-thiazolidin towards invertebrates.

 

The key study was performed with the harlequin fly Chironomus riparius accroding to OECD 235. Larvae of Chironomus riparius were exposed for 48 hours in a static test system to concentrations of 1.00, 2.20, 4.80, 10.6, 23.4 and 51.5 µg a.i./L. Mean measured concentrations were in a range of 95.7 and 101.2 % of nominal concentrations. The EC50 (48 h) for mobility was determined to be 10.8 µg/L (nominal).

This result is supported by further experimental studies assessing the acute toxicity of the test item.

 

The first supporting study was performed according to OECD 202 with water flea Daphnia magna under static conditions. First instars were exposed to a concentration range between 1.0 and 100 mg a.i./L. Mean measured test concentrations of the test substance during the whole test period ranged from 85 - 105 % of nominal concentrations. As in the highest concentration only 20 % mortality was observed after 48 hours, an EC50-calculation could not be performed. The LC50 (48 h) is therefore determined to be > 85.1 mg a.i./L (mean measured) and therefore considerably higher than the key value.

A second supporting study assessed the acute toxicity of the test item in Hyalella azteca according to EPA OPP 72-2 in a static system. H. azteca were exposed to nominal concentrations ranging from 6.25 and 100 µg a.i./L. Mean measured concentrations were between 91 – 100 % of nominal concentrations. The LC50 (96 h) was determined to be 40.7 µg a.i./L (mean measured).

Four further supporting experimental studies assessed the short-term toxicity of the test item according to OECD Guideline 202 under static conditions with different invertebrate species.

Field collected mayflies (Ecdyonurus sp.) larvae were exposed for 48 hours under static conditions to the nominal concentration range from 0.004 to 0.09 mg a.i./L. Mean measured test concentrations of the test substance ranged from 75 – 93 % of nominal concentrations. The derived LC50 (48 h) and EC50 (48 h) values were 0.0238 mg a.i./L and 0.0077 mg a.i./L, respectively, based on nominal concentrations.

Field collected caddis flies (Sericostoma personatum) were exposed to nominal concentrations between 0.001 and 1 mg a.i./L. No analysis was performed for this range-finding test. The EC50 (48 h) value for immobility in S. personatum larvae was observed to be between 0.1 and 1.0 mg a.i./L (nominal).

Asellus aquaticus was exposed to five concentrations between 0.009 and 0.20 mg a.i./L. Mean measured test concentrations of the test substance were in the range 93 – 94 % of nominal concentrations. The derived LC50 (48 h) value for mortality to A. aquaticus was 0.0989 mg a.i./L (nominal). The EC50 (48 h) value for mortality and immobility was 0.0758 mg a.i./L (nominal).

Amphipod Gammarus pulex were exposed to nominal concentrations ranging from 0.004 to 2.0 mg a.i./L. Mean measured concentrations were between 88 – 97 % of nominal concentrations. EC50 (48 h) value for immobility was determined to be 0.068 mg a.i./L (nominal) and the LC50 (48 h) value for mortality in G. pulex was 0.056 mg a.i./L (nominal).

 

Furthermore, one study assessing the toxicity of the test item to a saltwater species is available. In this study, saltwater mysids (Americamysis bahia) were exposed to a geometric series of six test concentrations of the test item in a static toxicity test according to EPA OPP 72-3. Mean measured concentrations ranged from 102 – 112 % of nominal concentrations. The LC50 (96h) was determined to be 0.31 µg a.i./L (mean measured).