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 terrestrial plants

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to terrestrial plants: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07 Feb - 13 Mar 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 208 (Terrestrial Plants, Growth Test)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Spray solution

Vehicle:

no

Details on preparation and application of test substrate:

- Method of application to soil surface: The test item was dissolved in deionised water and was applied once with 200 L/ha using a spray chamber.
- Controls: 200 L deionized water/ha

Species:

Zea mays

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Corn
- Plant family: Poaceae
- Variety: Aventura
- Source of seed: KWS Saat AG
- Prior seed treatment/sterilization: no treatment with pesticides or repellents prior to test initiation.
- Historical germination of seed (germination of seed lot tested): 95%
- Seed storage: Seeds were stored in the dark in plastic boxes in a refrigerator.

Species:

Triticum aestivum

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Wheat
- Plant family: Poaceae
- Variety: Triso
- Source of seed: Deutsche Saatveredelung
- Prior seed treatment/sterilization: no treatment with pesticides or repellents prior to test initiation.
- Historical germination of seed (germination of seed lot tested): 100%
- Seed storage: Seeds were stored in the dark in plastic boxes in a refrigerator.

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Oat
- Plant family: Poaceae
- Variety: Flämingstern
- Source of seed: Samen Schlereth
- Prior seed treatment/sterilization: no treatment with pesticides or repellents prior to test initiation.
- Historical germination of seed (germination of seed lot tested): 80%
- Seed storage: Seeds were stored in the dark in plastic boxes in a refrigerator.

Species:

Allium cepa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Onion
- Plant family: Liliaceae
- Variety: Braunschweiger blutrot
- Source of seed: Enza Zaden
- Prior seed treatment/sterilization: no treatment with pesticides or repellents prior to test initiation.
- Historical germination of seed (germination of seed lot tested): 100%
- Seed storage: Seeds were stored in the dark in plastic boxes in a refrigerator.

Species:

Lycopersicon esculentum

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Tomato
- Plant family: Solanaceae
- Variety: Balkonstar
- Source of seed: Enza Zaden
- Prior seed treatment/sterilization: no treatment with pesticides or repellents prior to test initiation.
- Historical germination of seed (germination of seed lot tested): 100%
- Seed storage: Seeds were stored in the dark in plastic boxes in a refrigerator.

Species:

Helianthus annuus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Sunflower
- Plant family: Asteraceae
- Variety: Pacino Cola
- Source of seed: Schlereth
- Prior seed treatment/sterilization: no treatment with pesticides or repellents prior to test initiation.
- Historical germination of seed (germination of seed lot tested): 90%
- Seed storage: Seeds were stored in the dark in plastic boxes in a refrigerator.

Species:

Glycine max (G. soja)

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Soybean
- Plant family: Fabaceae
- Variety: Protina
- Source of seed: Schlereth
- Prior seed treatment/sterilization: no treatment with pesticides or repellents prior to test initiation.
- Historical germination of seed (germination of seed lot tested): 95%
- Seed storage: Seeds were stored in the dark in plastic boxes in a refrigerator.

Species:

Cucumis sativus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Cucumber
- Plant family: Cucurbitaceae
- Variety: Delikatess
- Source of seed: Enza Zaden
- Prior seed treatment/sterilization: no treatment with pesticides or repellents prior to test initiation.
- Historical germination of seed (germination of seed lot tested): 100%
- Seed storage: Seeds were stored in the dark in plastic boxes in a refrigerator.

Species:

Beta vulgaris

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Sugar beet
- Plant family: Chenopodiaceae
- Variety: Mosaik
- Source of seed: Schlereth
- Prior seed treatment/sterilization: no treatment with pesticides or repellents prior to test initiation.
- Historical germination of seed (germination of seed lot tested): 80%
- Seed storage: Seeds were stored in the dark in plastic boxes in a refrigerator.

Species:

Brassica napus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Oilseed rape
- Plant family: Brassicaceae
- Variety: Vision
- Source of seed: Schmitt
- Prior seed treatment/sterilization: no treatment with pesticides or repellents prior to test initiation.
- Historical germination of seed (germination of seed lot tested): 100%
- Seed storage: Seeds were stored in the dark in plastic boxes in a refrigerator.

Test type:

seedling emergence and seedling growth test

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

28 d

Remarks:

14 days following the emergence of 70% of the control seedlings.

Test temperature:

Day: 23 ± 8 °C
Night: 18 ± 8 °C

pH:

7.3

Moisture:

70 ± 30%

Details on test conditions:

TEST SYSTEM
- Testing facility: glasshouse
- Test container (type, material, size): commercial plastic flower pots (10.5 cm diameter)
- Amount of soil: not reported
- Method of seeding: Seeds were pressed into the soil surface and covered with a layer of the used soil.
- No. of seeds per container: 5
- No. of replicates per treatment group: 4
- No. of replicates per control: 4

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Composition: mixture of 90% standard silt loam soil + 10% washed sand; soil was sieved to 2 mmand sterilized at 120 °C for about 30 min
- Organic carbon (%): 0.81%
- Lime content: 2.0% CaCO3
- Maximum water holding capacity (in % dry weigth):

GROWTH CONDITIONS
- Photoperiod: Regulated to maintain at least 16 h light
- Light source: Natural daylight supplemented by artificial lighting
- Light intensity and quality: Regulation: at light intensities > 15000 lux the lamps turn off and when > 50000 lux the shading closes
- Day/night temperatures: Regulated to maintain 23 ± 8 °C day and 18 ± 8 °C night
- Relative humidity (%): Regulated to maintain 70 ± 30%
- Watering regime and schedules: Following the initial top watering to facilitate germination of the seed until validity criteria for germination were reached, further irrigation was provided to the pots by bottom watering via saucers standing below each pot. Water was given and retained within the saucer according to the need of the plants in order to have an optimal water supply for plant growth.
- Water source/type: not reported
- Volume applied: not reported
- Any pest control method/fertilization: 2.4 g Blaukorn per liter in test soil; no liquid fertilization

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : emergence (daily), survival and phytotoxicity (day 7 and 14 after emergence of 70% of the seeds in the control), growth stages and shoot dry weight (final assessment at test end)

- Phytotoxicity rating system (if used): 0 = no injury or effect, A = slight symptom (s), B = moderate symptom (s), C = severe symptom (s), D = total plant symptom (s), E = moribund

Nominal and measured concentrations:

Nominal concentration: 0.4 L test item/ha (≙ 96 g a.i./ha ≙ 0.064 µg/kg soil dw)

Reference substance (positive control):

no

Species:

other: Beta vulgaris, Brassica napus, Cucumis sativus, Glycine max, Helianthus annuus, Lycopersicon esculentum, Allium cepa, Avena sativa, Triticum aestivum, Zea mays

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 64 µg/kg soil dw

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

seedling emergence

Remarks:

and growth

Remarks on result:

other: Recalculated effect result using a default depth of 10 cm and soil density of 1500 kg/m3

Species:

other: Beta vulgaris, Brassica napus, Cucumis sativus, Glycine max, Helianthus annuus, Lycopersicon esculentum, Allium cepa, Avena sativa, Triticum aestivum, Zea mays

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 96 g/ha

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

seedling emergence

Remarks:

and growth

Remarks on result:

other: Recalculated based on target substance concentration in formulation (240 g/L)

Species:

other: Beta vulgaris, Brassica napus, Cucumis sativus, Glycine max, Helianthus annuus, Lycopersicon esculentum, Allium cepa, Avena sativa, Triticum aestivum, Zea mays

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.4 other: L/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks:

and growth

Details on results:

SEED GERMINATION
- Percent seed germination: control: 80% (Helianthus annuus) - 100% (Brassica napus, Cucumis sativus, Avena sativa)

SEEDLING EMERGENCE
- Percent seedling emergence: control: 80% (Helianthus annuus) - 100% (Brassica napus, Cucumis sativus, Avena sativa)
- Percent survival: control: 100%
- Abnormal seed development or appearance: control and treatment group: no sign of phytotoxicity on day 14
- Phytotoxicity: No signs of phytotoxicity were observed.

Reported statistics and error estimates:

Statistical analysis of shoot dry weight data was conducted by using the Mann-Whitney-U-Test, one sided smaller, p < 0.05 by ToxRat software.

Figure 1: Summary of the findings for each species

Species	Emergence (% inhibition)	Survival (% inhibition)	Phytotoxicity	Shoot Dry Weight (% inhibition)	BBCH (control / treated) min - max
Dicotyledoneae
Beta vulgaris	11.1	6.3	0	-0.4	12-14/12-14
Brassica napus	0	0	0	-2.2	13-14/13-14
Cucumis sativus	0	0	0	2.2	12-13/12-13
Glycine max	5.3	0	0	-3.2	12-13/12-13
Helianthus annus	-6.3	0	0	3.9	14-16/14-16
Lycopersicon esculentum	5.3	0	0	2.7	13-14/13-14
Monocotyledoneae
Allium cepa	11.1	0	0	11.5	11-12/10-12
Avena sativa	0	0	0	-7.3	12-13/12-13
Triticum aestivum	-5.3	0	0	-5.0	13-21/13-21
Zea mays	0	0	0	-2.5	13-14/13-14

Negative figures indicate that there was an increase when compared to the control

Table 2: Results of survival and emergence in controls

Species	% emerged in control	% survival in control
Dicotyledoneae
Beta vulgaris	90	100
Brassica napus	100	100
Cucumis sativus	100	100
Glycine max	95	100
Helianthus annus	80	100
Lycopersicon esculentum	95	100
Monocotyledoneae
Allium cepa	90	100
Avena sativa	100	100
Triticum aestivum	95	100
Zea mays	100	100

Table 3: Effects on shoot dry weight

Species	Mean value dry weight/plant in control	Mean value dry weight/plant in treatment group
Dicotyledoneae
Beta vulgaris	0.120	0.120
Brassica napus	0.171	0.174
Cucumis sativus	0.404	0.395
Glycine max	0.485	0.500
Helianthus annus	0.150	0.144
Lycopersicon esculentum	0.120	0.116
Monocotyledoneae
Allium cepa	0.010	0.009
Avena sativa	0.085	0.091
Triticum aestivum	0.133	0.140
Zea mays	0.274	0.281

Table 4: Validity criteria for OECD 208

Criterion	Outcome	Criterion fulfilled
Seedling emergence in the controls is ≥ 70%.	80 - 100%	yes
No visible phytotoxic effects (e.g. chlorosis, necrosis, wilting, deformatons) in control seedlings and the plants of every particular species exhibit normal variation in growth and morphology.	No visible phytotoxic effects in controls	yes
In the controls, the mean survival of emerged control seedlings is ≥ 90% for the duration of the study.	100%	yes
The environmental conditions for a particular species are identical and the growing media contain the same amount of soil matrix, support media or substrate from the same source.	Identical conditions for all species	yes

Validity criteria fulfilled:

yes

Remarks:

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

Conclusions:

The NOEC (28 d) was determined to be ≥ 0.4 L test item/ha, corresponding to 64 µg/kg soil dw, in an Seedling Emergence & Growth Test (OECD 208) with 10 plant species.

Reference 2

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

08 - 23 Dec 1998

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EPA OPP 122-1 (Terrestrial Plant Toxicity Tier I (vegetative vigor))

Version / remarks:

1986

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Species:

Phaseolus vulgaris

Plant group:

Dicotyledonae (dicots)

Species:

Brassica rapa

Plant group:

Dicotyledonae (dicots)

Species:

Daucus carota

Plant group:

Dicotyledonae (dicots)

Species:

Lactuca sativa

Plant group:

Dicotyledonae (dicots)

Species:

Glycine max (G. soja)

Plant group:

Dicotyledonae (dicots)

Species:

Lycopersicon esculentum

Plant group:

Dicotyledonae (dicots)

Species:

Zea mays

Plant group:

Monocotyledonae (monocots)

Species:

Allium cepa

Plant group:

Monocotyledonae (monocots)

Species:

Lolium perenne

Plant group:

Monocotyledonae (monocots)

Species:

Triticum aestivum

Plant group:

Monocotyledonae (monocots)

Test type:

vegetative vigour test

Study type:

semi-field study

Remarks:

Greenhouse study

Substrate type:

natural soil

Total exposure duration:

14 d

Nominal and measured concentrations:

Nominal: 0.5 Ibs a.i./acre (562 g a.i./ha). The nominal concentration of the test substance in the spray mixture was 2396 ppm.
Measured: 92 and 88% of the nominal concentration

Species:

Phaseolus vulgaris

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.375 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

phytotoxicity

Remarks on result:

other: Recalculated effect result using a default depth of 10 cm and soil density of 1500 kg/m3

Species:

Brassica rapa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.375 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

phytotoxicity

Remarks on result:

other: Recalculated effect result using a default depth of 10 cm and soil density of 1500 kg/m3

Species:

Daucus carota

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.375 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

phytotoxicity

Remarks on result:

other: Recalculated effect result using a default depth of 10 cm and soil density of 1500 kg/m3

Species:

Lactuca sativa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.375 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

phytotoxicity

Remarks on result:

other: Recalculated effect result using a default depth of 10 cm and soil density of 1500 kg/m3

Species:

Glycine max (G. soja)

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.375 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

phytotoxicity

Remarks on result:

other: Recalculated effect result using a default depth of 10 cm and soil density of 1500 kg/m3

Species:

Lycopersicon esculentum

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.375 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

phytotoxicity

Remarks on result:

other: Recalculated effect result using a default depth of 10 cm and soil density of 1500 kg/m3

Species:

Zea mays

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.375 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

phytotoxicity

Remarks on result:

other: Recalculated effect result using a default depth of 10 cm and soil density of 1500 kg/m3

Species:

Allium cepa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.375 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

phytotoxicity

Remarks on result:

other: Recalculated effect result using a default depth of 10 cm and soil density of 1500 kg/m3

Species:

Lolium perenne

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.375 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

phytotoxicity

Remarks on result:

other: Recalculated effect result using a default depth of 10 cm and soil density of 1500 kg/m3

Species:

Triticum aestivum

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 0.375 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

phytotoxicity

Remarks on result:

other: Recalculated effect result using a default depth of 10 cm and soil density of 1500 kg/m3

Validity criteria fulfilled:

not specified

Conclusions:

A postemergent exposure of the test substance to ten species of nontarget plants had no phytotoxic effects on seedling survival and growth up to the maximum challenge rate of 0.5 lbs a.i./acre. The no-observed-effect-level for the substance was 0.5 Ibs a.i./acre.

Description of key information

NOEC (28 d) ≥ 64 µg/kg soil dw (initial. measured, OECD 208)

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for terrestrial plants:

64 µg/kg soil dw

Additional information

Two GLP studies are available assessing the toxicity of 3-(2-chlor-5-pyridyl-methyl)-cyanimino-1,3-thiazolidin on terrestrial plants.

The key study evaluated the effects of the target substance on the seedling emergence and growth of ten non-target terrestrial plant species following a pre-emergence application of the test item on the soil surface according to OECD 208. The soil surface was treated with 0.4 L test item/ha test item using a laboratory track sprayer. The water volume rate was 200 L/ha. Each pot (replicate) contained 5 seeds and there were 20 seeds treated, i.e. 4 replicates. Control pots were treated with deionised water. Emergence, survival and visual phytotoxicity were then recorded 7 and 14 days once 70 % emergence had been achieved against the deionised water treated controls. The study was terminated 14 days after 70 % emergence in the controls of each species. Analysis of the target substance in the spray solution revealed it to be 103.3 % of nominal. No adverse effects on emergence, seedling survival, visual phytotoxicity, growth and shoot dry weight reaching or exceeding the 50 % effect level were observed. The NOEC (28 d) was therefore determined to be ≥ 0.4 L test item/ha corresponding to ≥ 96 g a.i./ha, which corresponds to ≥ 64 µg/kg soil dw (recalculated result using a default depth of 10 cm and soil density of 1500 gk/m3).

In another study, a postemergent application of the test substance to seedlings was used to evaluate the phytotoxicity of the test substance to non-target terrestrial plants in a greenhouse study, according to the EPA OPP 122-1 (Terrestrial Plant Toxicity Tier I (vegetative vigor)) guideline. Ten species of plants were tested including six dicots and four monocots. No treatment related effects for survival, plant height, plant dry weight and phytotoxicity were noted at an application rate of 562 g a.i./ha which corresponds to 0.375 mg a.i./kg soil dw (NOEC (14 d) ≥ 0.375 mg a.i./kg soil dw).