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

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

31 May - 04 Aug 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))

Version / remarks:

2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

- Method of mixing into soil: Prior to the start of the test, the application solution of the highest test concentration of the test item was prepared. The test item was mixed into deionised water as homogeneously as possible. The application solution of the highest test concentration was further diluted with deionised water to obtain the desired test concentrations. The application solutions were thoroughly mixed into the artificial soil of each replicate using a laboratory mixer.
- Controls: deionised water only in soil

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: earthworm
- Source: laboratory culture (originally obtained from Prof. Graff, Forschungsanstalt für Landwirtschaft, Braunschweig, Germany)
- Age at test initiation: adult worms (approx. 6 months old, with a well developed clitellum), age difference 4 weeks
- Weight at test initiation (range): 0.25 - 0.44 g

ACCLIMATION
- Acclimation period: 1 day
- Acclimation conditions (same as test or not): same as test

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

8 wk

Test temperature:

18 - 22 °C

pH:

5.54 - 6.77

Moisture:

22.36 - 25.12 %
53.85 - 62.72 % of WHCmax

Details on test conditions:

TEST SYSTEM
- Test container (material, size): non-re-usable plastic boxes (length x width x height ca. 16.5 cm x 12 cm x 6 cm, area approximately 200 cm2)
- Amount of soil or substrate: 500 g (dw)
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 4

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Soil texture:
- % sand: 73.82
- % clay: 20
- Composition (if artificial substrate): sphagnum peat (shredded): 5 %, kaolinite clay (content of Kaolinite = 30.2 %) 20 %, industrial quartz sand (particle size: 0.20 mm – 0.05 mm = 91.35 %): 73.82 %, calcium carbonate for the adjustment to pH 6.0 ± 0.5 (CaCO3): 0.18 %, food (dried ground cow manure): 1 %
- Maximum water holding capacity (in % dry weigth): 53.85 - 62.72%

OTHER TEST CONDITIONS
- Photoperiod: 16:8 h light:dark
- Light intensity: 551 - 595 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : survival of adult worms, abnormal behaviour and growth (after 4 wk), number of offspring (after 8 wk), food consumption (at each feeding date)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 0.2, 0.4, 0.8, 1.6, 3.2 and 6.4 mg test item/kg dw (≙ 45.2, 90.4, 181, 362, 723 and 1427 µg a.i/kg dw, based on test item purity of 22.6 %)

Reference substance (positive control):

yes

Remarks:

Carbendazim

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

0.8 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

0.181 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Remarks on result:

other: Recalculated based on test item purity of 22.6%

Details on results:

- Mortality at end of exposure period: No mortality of adult earthworms was observed after 28 days of exposure at the control group and at any test item concentration including the highest test concentration

Results with reference substance (positive control):

- Results with reference substance valid? yes, according to OECD 222, Carbendazim has been shown to affect reproduction. Significant effects should be observed between 1 and 5 mg a.i./kg dw.
Tested concentrations: 0, 1.25, 2,5 and 5 mg a.s./kg dw
EC50 (56 d) = 1.66 mg a.i./kg dw (based on reproduction)

Table 1: Number of surviving adult earthworms and % mortality at day 28

mg test item/kg dry weight artificial soil	Box No.	Number of surviving worms	No. of dead worms	Mortality [%] per replicate
		Day 0            Day 2
	1	10                 10	0	0
	2	10                 10	0	0
	3	10                 10	0	0
Control	4 5	10                 10 10                 10	0 0	0 0
	6	10                 10	0	0
	7	10                 10	0	0
	8	10                 10	0	0
Mean		10                 10	0	0
standard deviation		0                   0	0	0
	1	10                 10	0	0
0.2	2 3	10                 10 10                 10	0 0	0 0
	4	10                 10	0	0
Mean		10                 10	0	0
Standard deviation		0                   0	0	0
	1	10                 10	0	0
0.4	2 3	10                 10 10                 10	0 0	0 0
	4	10                 10	0	0
Mean		10                 10	0	0
standard deviation		0                   0	0	0
	1	10                 10	0	0
0.8	2 3	10                 10 10                 10	0 0	0 0
	4	10                 10	0	0
Mean		10                 10	0	0
standard deviation		0                   0	0	0
	1	10                 10	0	0
1.6	2 3	10                 10 10                 10	0 0	0 0
	4	10                 10	0	0
Mean		10                 10	0	0
standard deviation		0                   0	0	0
	1	10                 10	0	0
3.2	2 3	10                 10 10                 10	0 0	0 0
	4	10                 10	0	0
Mean		10                 10	0	0
standard deviation		0                   0	0	0
	1	10                 10	0	0
6.4	2 3	10                 10 10                 10	0 0	0 0
	4	10                 10	0	0
Mean		10                 10	0	0
standard deviation		0                   0	0	0

Table 2: Body wet weight of adult earthworms

mg t. i./kg dry weight artificial soil	BoxNo.	Number of surviving		Mean weight of worms		weight change [%]
		Day 0	Day 28	Day 0	Day 28
	1	10	10	0.31	0.50	58.79
	2	10	10	0.32	0.48	52.05
	3	10	10	0.32	0.48	51.10
Control	4 5	10 10	10 10	0.33 0.30	0.49 0.45	49.70 50.67
	6	10	10	0.31	0.47	49.04
	7	10	10	0.32	0.51	58.93
	8	10	10	0.31	0.49	60.66
Mean		10	10	0.31	0.48	53.87
standard deviation		0	0	0.01	0.02	4.75
	1	10	10	0.34	0.53	58.21
0.2	2 3	10 10	10 10	0.31 0.29	0.47 0.46	51.60 60.21
	4	10	10	0.29	0.47	60.48
Mean		10	10	0.31	0.48	57.63
Standard deviation		0	0	0.02	0.03	4.14
	1	10	10	0.34	0.52	54.76
0.4	2 3	10 10	10 10	0.32 0.29	0.49 0.48	52.48 64.71
	4	10	10	0.32	0.49	55.84
Mean		10	10	0.32	0.50	56.95
standard deviation		0	0	0.02	0.02	5.36
	1	10	10	0.31	0.49	59.35
0.8	2 3	10 10	10 10	0.34 0.33	0.52 0.50	53.69 50.60
	4	10	10	0.33	0.49	46.71
Mean		10	10	0.33	0.50	52.59
standard deviation		0	0	0.01	0.01	5.34
	1	10	10	0.32	0.47	45.48
1.6	2 3	10 10	10 10	0.31 0.33	0.48 0.49	55.48 47.27
	4	10	10	0.32	0.51	57.76
Mean		10	10	0.32	0.49	51.50
standard deviation		0	0	0.01	0.02	6.03
	1	10	10	0.31	0.48	55.34
3.2	2 3	10 10	10 10	0.33 0.32	0.53 0.48	58.08 52.85
	4	10	10	0.35	0.54	55.30
Mean		10	10	0.33	0.51	55.39
standard deviation		0	0	0.02	0.03	2.14
	1	10	10	0.31	0.48	56.82
6.4	2 3	10 10	10 10	0.29 0.31	0.46 0.45	59.11 46.60
	4	10	10	0.32	0.49	52.47
Mean		10	10	0.31	0.47	53.75
standard deviation		0	0	0.01	0.02	5.50

Table 3: Juvenile earthworms/test vessel

mg test item/kg dry weight artificial soil	Control	0.2	0.4	0.8	1.6	3.2	6.4
Box No. 1	187	201	149	213	121	183	141
Box No. 2	181	227	198	187	133	130	213
Box No. 3	185	207	181	181	152	167	142
Box No. 4	245	177	166	221	170	141	181
Box No. 5	160
Box No. 6	181
Box No. 7	194
Box No. 8	226
Mean	194.9	203.0	173.5	200.5	144.0 *	155.3 *	169.3 *
SD	27.4	20.6	20.9	19.5	21.5	24.1	34.6
CV	14.0	10.1	12.1	9.7	14.9	15.6	20.4
% of control	---	104.2	89.0	102.9	73.9	79.7	86.9

*     statistical significance compared to the control (Williams Multiple Sequential t-test, one-sided smaller,α = 0.05)

Table 4: Validity criteria for OECD 222 (2016)

Criterion from the guideline to be satisfied in the controls	Outcome	Validity criterion fulfilled
Adult mortality over the initial 4 weeks of the test is ≤ 10%.	0%	yes
Each replicate (containing 10 adults) to have produced ≥ 30 juveniles by the end of the test.	194.9 (160 - 245)	yes
The coefficient of variation of reproduction is ≤ 30%.	14	yes

Validity criteria fulfilled:

yes

Remarks:

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

Conclusions:

The NOEC (56 d) was determined to be 0.8 mg test item /kg soil dw, corresponding to 0.181 mg a.i./kg soil dw (nominal) in an earthworm reproduction test with Eisenia fetida (OECD 222).

Reference 2

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

12 Sep -12 Oct 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Version / remarks:

1984

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

14 d

Nominal and measured concentrations:

Nominal concentrations: 1.0, 3.2, 10, 18, 32, 56, 100, 178, 316 und 1000 mg/kg soil dw

Reference substance (positive control):

yes

Remarks:

chloroacetamide

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

105 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% confidence limits: 90 - 122 mg/kg soil dw

Validity criteria fulfilled:

yes

Conclusions:

The derived LC50 (14 d) was determined to be 105 mg test item/kg soil dw in an earthworm acute toxicity test with Eisenia fetida (OECD 207).

Description of key information

NOEC (56 d) = 0.181 mg/kg soil dw (nominal, Eisenia fetida, OECD 222)

LC50 (14 d) = 105 mg/kg soil dw (nominal, Eisenia fetida, OECD 207)

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil macroorganisms:

105 mg/kg soil dw

Long-term EC10, LC10 or NOEC for soil macroorganisms:

0.181 mg/kg soil dw

Additional information

Two studies according to GLP are available assessing the toxicity to earthworms.

The key study determined the long-term affects of a formulation containing the target substance (22.6 %) in an earthworm reproduction test with Eisenia fetida according to OECD 222. Adult earthworms were exposed in an artificial soil (with 5 % peat content) to the nominal test concentrations of 0.2, 0.4, 0.8, 1.6, 3.2 and 6.4 mg test item/kg soil dw (corresponding to 45.2, 90.4, 181, 362, 723 and 1427 µg a.i/kg soil dw). The test item was mixed into the soil. After 28 days the number of surviving animals and their weight alteration was determined. They were then removed from the artificial soil. After further 28 days, the number of offspring was determined. After 28 days of exposure no worms died in the control group and no mortality was observed at any test item concentration. Statistically significant different values for the growth relative to the control were not observed at any concentration. Statistically significant different values for the number of juveniles per test vessel relative to the control were observed at the three highest test concentration of up to 6.4 mg test item/kg dry weight artificial soil. The NOEC (56 d) was therefore determined to be 0.8 mg test item/kg soil dw corresponding to 0.181 mg a.i./kg soil dw (nominal).

The second study assessed the acute toxicity of the target substance in artificial soil according to OECD 207. Adult animals were exposed to test item concentrations ranging from 1.0 to 1000 mg/kg soil dw. The test compound was thoroughly mixed into the artificial soil. After 14 days, the number of surviving animals and their weight alteration during the test period was determined. The derived LC50 (14 d) was 105 mg/kg dw soil (nominal).