Imidazolium compounds, 2-C17-unsatd.-alkyl-1-(2-C18-unsatd. amidoethyl)-4,5-dihydro-N-methyl, Me sulfates

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Endpoint:

toxicity to terrestrial plants: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2021-06-18 to 2021-08-18 (final report date xx-xx-xxxx)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

ISO 22030 (Soil quality - Biological methods - Chronic toxicity in higher plants)

Version / remarks:

2005

Deviations:

yes

Remarks:

The factor used for calculation of the test concentrations for the guideline plant species turnip was > 2.0 to cover all endpoints.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Details on preparation and application of test substrate:

- Method of mixing into soil (if used): The respective test item amount was pipetted and dispersed in tap water for each test item concentration and applied to the surface of the soil. Additional tap water was added to adjust the humidity of the soil (45 % of the MWHC). Afterwards, the soil was mixed for ca. 3 minutes to ensure a homogeneous distribution of the test item in the soil. 400 g of the treated soil were transferred to the test container and the seeds were sown.
- Controls: Untreated natural soil (mixture) was tested under the same conditions as the test replicates.

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: oats
- Plant family: Poaceae (Gramineae)
- Variety: KWS Contender
- Source of seed: KWS Lochow GmbH, Ferdinand-von-Lochow-Straße 5, 29303 Bergen, Germany
- Seed storage: The seeds were stored dark at the test facility at room temperature (22 ± 10 °C) and protected from moisture until use.

Species:

Brassica rapa

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: turnip
- Plant family: Brassicaceae
- Variety:
- Source of seed: Carolina Biological Supply Company, 2700 York Road, Burlington, NC 27215-3398, USA
- Seed storage: The seeds were stored dark at the test facility at room temperature (22 ± 10 °C) and protected from moisture until use.

Test type:

seedling emergence toxicity / vegetative vigour test

Study type:

laboratory study

Substrate type:

other: 2:1 mixture of natural soil LUFA 2.2 (batch number: Sp2.20621, loamy sand (DIN classific.)) and quartz sand (12a).

Limit test:

no

Total exposure duration:

56 d

Remarks:

Oats: 56 days; 2021-06-18 to 2021-08-13 (definitive harvest)
Turnip: 42 days; 2021-06-18 to 2021-07-30 (definitive harvest)

Test temperature:

Nominal 22 ± 10 °C; Actual 16.0 - 29.9

pH:

soil pH 5.50 ± 0.22

Moisture:

adjusted to 45 % of the MWHC at test start.
Nominal Relative humidity 70% ± 30%;
Actual Relative humidity 28.6% - 97.4%

Details on test conditions:

TEST SYSTEM
- Test container (type, material, size): Plastic container (10 cm diameter) including glass fibre wicks to ensure homogeneous watering. Each test container was placed on an individual water reservoir.
- Amount of soil: 400 g/container
- Method of seeding: Test containers were filled each with the same amount of treated soil (see application technique) and seeding holes were made with a seeding pistil. One seed was given in each hole and covered with soil.
- No. of seeds per container: 10 seeds per test container
- No. of plants (retained after thinning): After complete emergence the number of emerged seedlings was determined and the emerged were thinned out to 8 seedlings per replicate. At the first harvest (day 21) the plants were thinned out to 4 plants per replicate.
- No. of replicates per treatment group: 6 replicates per test concentration tested in a randomised block design
- No. of replicates per control: 6 replicates per control tested in a randomised block design

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Description: A 2:1 mixture of natural soil LUFA 2.2 (batch number: Sp2.20621, loamy sand (DIN classification)) and quartz sand (12a) was used. Grain size: <= 2 mm
- Geographic location:
-- Soil: Landwirtschaftliche Untersuchungs- und Forschungsanstalt Speyer (LUFA), Obere Langgasse 40, 67346 Speyer, Germany
-- Sand: Dörentrup Quarz GmbH Co. KG, An der Sandgrube 1, 31089 Duingen, Germany
- % sand: Sand (0.063 - 2 mm): 84.9%
- % silt: Silt (0.002 - 0.063 mm): 9.7%
- % clay: Clay (< 0.002 mm): 5.4%
- Soil taxonomic classification: loamy sand
- Soil classification system: DIN classification
- Organic carbon (%): Carbon content: 1.05%
- Maximum water holding capacity: 37.6 g/100 g soil

GROWTH CONDITIONS
- Photoperiod: 16 h
- Light intensity and quality (µmol/m2 sec): Nominal 350 ± 50; Actual 380 ± 22
- Day/night temperatures: Nominal 22 ± 10 °C, Actual 16.0 - 29.9 °C
- Relative humidity (%): Nominal 70 ± 30; Actual 28.6 - 97.4
- Watering regime and schedules:
-- Water source/type: tap water
-- Volume applied: 10.65 g/100 g soil at test start
-- Interval and method of applications: The test containers were bottom watered as needed, with nutrient solution via glass fibre wicks.
-- Method of application:
-- Any pest control method/fertilization (if used): HAKAPHOS® SOFT SPEZIAL 16+8+22(+3), Origin: Grünes Landhaus, St. Godehard-Str. 23, 31139 Hildesheim, Germany. For watering a 0.5 ‰ solution was used.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- acute effects: shoot height, shoot fresh and dry weight, water content of the shoots
- chronic effects (blossom / husks fresh and dry weight, water content, number of blossoms / husks)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: oats: 2; turnip: 3
- Range finding study: yes, 4 replicates per concentration and control. Test duration 42 days for turnip and 57 days for oats, respectively. At test end number of blossoms / husks and fresh and dry weight of the shoots, blossoms and husks were determined.
-- Test concentrations: 1, 10, 100, 1000 mg a.i./kg DW
-- Results used to determine the conditions for the definitive study

Nominal and measured concentrations:

Oats: 1000 - 500 - 250 - 125 - 62.5 mg a.i./kg DW nominal;
Turnip: 1000 - 333 - 111 - 37.0 - 12.3 - 4.11 - 1.37 - 0.457 mg a.i./kg DW nominal

Reference substance (positive control):

no

Remarks:

No reference item is recommended for this test acc. to the guideline.

Key result

Species:

Avena sativa

Duration:

69 d

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: Shoot height; Shoot fresh weight; Shoot dry weight; Water content of shoots

Key result

Species:

Brassica rapa

Duration:

42 d

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: Shoot height; Shoot fresh weight; Shoot dry weight; Water content of shoots

Key result

Species:

Avena sativa

Duration:

69 d

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: BBCH code; Number of blossoms; Blossom fresh weight; Blossom dry weight; Water content of blossoms

Key result

Species:

Brassica rapa

Duration:

42 d

Dose descriptor:

NOEC

Effect conc.:

111 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: Number of husks

Key result

Species:

Brassica rapa

Duration:

42 d

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: Number of husks

Key result

Species:

Brassica rapa

Duration:

42 d

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: BBCH code; Husk fresh weight; Husk dry weight; Water content of husks

Details on results:

Seedling Emergence
- Percent seedling emergence (day 7): Oats: 87% - 97%; Turnip: 85% - 97%

First Harvest
For both plant species no test item related visual phytotoxic effects occurred after 21 days.

Definitive Harvest
Oats: The definitive harvest was done on day 56.
No significant effects were found on shoot height, shoot fresh weight, dry weight and water content of the shoots and blossom and the number of blossoms.

Turnip: The definitive harvest was done on day 42.
No significant effect on shoot height, biomass as fresh and dry weight of the shoots and husks, and water contents of shoots and husks were found.
Significant effects were seen regarding the number of husks.
Please refer to "Any other information on results incl. tables"

Reported statistics and error estimates:

Inhibition of biomass growth:
The percent inhibition of biomass growth (biomass of shoots, blossom and husks) was calculated in relation to the control.
All dead plants were measured, weight out and observed and included in the calculation as possible.

NOEC of biomass:
One Way Analysis of Variance (ANOVA) and DUNNET`S test, if necessary, were carried out for the determination of statistically significant differences compared to the control replicates. When running a One Way Analysis of Variance a Normality test and an Equal Variance test were done first. P-values for both Normality and Equal Variance test were 0.05. The α-value for ANOVA and DUNNET`S test (acceptable probability of incorrectly concluding that there is a difference) is α = 0.05.
Failure of the normality test and / or equal variance test can be caused by extremely homogeneous emergence and growth patterns as opposed to higher variances in other treatments. Due to the high and even number of replicates in the control and treatment groups, the failure had no influence on the robustness of the calculations.

EC-values and confidence intervals of growth:
EC25- and EC50- values were calculated by sigmoidal dose-response regression using GraphPadPrism. Four parameter were used for dose-response fitting. Calculation of the confidence intervals for EC-values was carried out using standard procedures provided by GraphPadPrism.

Acute Effects

Oats: Acute Effects: NOEC, EC₂₅ and EC₅₀ Values with Confidence Range (p)

Parameter	NOEC [mg a.i./kg DW]	EC25 [mg a.i./kg DW]	p = 95% [mg a.i./kg DW]	EC50 [mg a.i./kg DW]	p = 95% [mg a.i./kg DW]
Shoot height	1000	> 1000	̶	> 1000	̶
Shoot fresh weight	1000	> 1000	̶	> 1000	̶
Shoot dry weight	1000	> 1000	̶	> 1000	̶
Water content of shoots	1000	> 1000	̶	> 1000	̶

 

 

Turnip: Acute Effects: NOEC, EC₂₅ and EC₅₀ Values with Confidence Range (p)

Parameter	NOEC [mg a.i./kg DW]	EC25 [mg a.i./kg DW]	p = 95% [mg a.i./kg DW]	EC50 [mg a.i./kg DW]	p = 95% [mg a.i./kg DW]
Shoot height	1000	> 1000	̶	> 1000	̶
Shoot fresh weight	1000	> 1000	̶	> 1000	̶
Shoot dry weight	1000	> 1000	̶	> 1000	̶
Water content of shoots	1000	> 1000	̶	> 1000	̶

-)          not determinable

 

 

Chronic Effects

Oats: Chronic Effects: NOEC, EC₂₅ and EC₅₀ Values with Confidence Range (p)

Parameter	NOEC [mg a.i./kg DW]	EC25 [mg a.i./kg DW]	p = 95% [mg a.i./kg DW]	EC50 [mg a.i./kg DW]	p = 95% [mg a.i./kg DW]
Number of blossoms	1000	> 1000	̶	> 1000	̶
Blossom fresh weight	1000	> 1000	̶	> 1000	̶
Blossom dry weight	1000	> 1000	̶	> 1000	̶
Water content of blossoms	1000	> 1000	̶	> 1000	̶

 

Turnip: Chronic Effects: NOEC, EC₂₅ and EC₅₀ Values with Confidence Range (p)

Parameter	NOEC [mg a.i./kg DW]	EC25 [mg a.i./kg DW]	p = 95% [mg a.i./kg DW]	EC50 [mg a.i./kg DW]	p = 95% [mg a.i./kg DW]
Number of husks	111	404	< 0.457 - > 1000	> 1000	̶
Husk fresh weight	1000	> 1000	̶	> 1000	̶
Husk dry weight	1000	> 1000	̶	> 1000	̶
Water content of husks	1000	> 1000	̶	> 1000	̶

-)          not determinable

 

Validity criteria fulfilled:

yes

Remarks:

- minimum of 75 % emergence in the control; - the mean seedling growth exhibited no visible phytotoxic effects and the plants exhibited only normal variation in growth and morphology; - number of dead control plants was ≤ 1 plant / replicate

Conclusions:

The validity criteria for controls as defined by the guideline have been fulfilled.

Oats: The definitive harvest was done on day 56.
No significant effects were found on shoot height, shoot fresh weight, dry weight and water content of the shoots and blossom and the number of blossoms.

Turnip: The definitive harvest was done on day 42.
No significant effect on shoot height, biomass as shoot fresh and dry weight of the shoots, husks, and water contents were found.
Significant effects were seen regarding the number of husks; the NOEC was determined to be 111 mg a.i/kg DW, with an EC50 of > 1000 mg a.i./kg DW.

Executive summary:

The effect of the test item seedling emergence and vegetative vigour of monocot Avena sativa (oats) and dicot Brassica rapa (turnip) crops was studied at nominal test item concentrations of 1000 - 500 - 250 - 125 - 62.5 mg a.i./kg DW for oats and 1000 - 333 - 111 - 37.0 - 12.3 - 4.11 - 1.37 - 0.457 mg a.i./kg DW for turnip.
The growth medium used was a 2:1 mixture of natural soil and sand.
The test item was incorporated into the soil once before the seeds were sown.
The rate of emergence was determined on day 7 and the plants were reduced to a maximum of 8 plants per replicate. At the first harvest (day 21) the plants were thinned out to 4 plants per replicate and the shoot height, the fresh weight and the number of buds and blossoms (turnip) of the harvested plants were determined.
At the definitive harvest (oats day 56, turnip day 42) the number of blossoms and husks, respectively, the shoot height, the biomass (fresh and dry weight) and the water content of the shoots, husks and blossoms, respectively, were determined.

Emergence
The % seedling emergence was not significantly affected in both species.

First Harvest
For both plant species no test item related visual phytotoxic effects occurred after 21 days.

Definitive Harvest
Oats: No significant effects were found on shoot height, shoot fresh weight, dry weight and water content of the shoots and blossom and the number of blossoms.
Turnip: No significant effect on shoot height, biomass as shoot fresh and dry weight of the shoots, husks, and water contents were found.
Significant effects were seen regarding the number of husks; the NOEC was determined to be 111 mg a.i/kg DW, with an EC50 of > 1000 mg a.i./kg DW.

Results Synopsis
Monocot
EC₅₀:     > 1000 mg a.i./kg DW.
NOEC:     1000 mg a.i./kg DW.

Dicot
EC₅₀:     > 1000 mg a.i./kg DW.
NOEC:     111 mg a.i/kg DW
Most sensitive parameter: number of husks

This toxicity study is classified as acceptable and satisfies the guideline requirement for a terrestrial plant chronic toxicity study.

Description of key information

Draft study report, according to DIN ISO 20030:2005, Chronic Toxicity in higher plants: The chronic toxicity of the test item to two terrestrial plant species was determined over a period of 69 days (oats) and 44 days (turnip). The test for the plant species oats was conducted at the test item concentrations 1000 - 500 - 250 - 125 - 62.5 mg a.i./kg DW (factor 2) and for the plant species turnip at the test concentrations 1000 - 333 - 111 - 37.0 - 12.3 - 4.11 - 1.37 - 0.457 mg a.i./kg DW (factor 3).;

NOEC acute: 1000 mg/kg soil dw

EC50 acute: 1000 mg/kg soil dw

NOEC long-term: 111 mg/kg soil dw (based on the interim results from the draft report for turnip)

EC50 long-term: 1000 mg/kg soil dw

Key value for chemical safety assessment

Short-term EC50 or LC50 for terrestrial plants:

1 000 mg/kg soil dw

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

111 mg/kg soil dw

Additional information

 

No final results for toxicity to terrestrial plants are available, however, draft results were used instead. Please note that due to the equivocal results no new risk assessment could be performed. A new rsik assessment including eventually changed exposure scenarios will be added as soon as possible in form of a spontaneous IUCLID update.

 

The effect of the test item seedling emergence and vegetative vigour of monocot Avena sativa (oats) and dicot Brassica rapa (turnip) crops was studied at nominal test item concentrations of 1000 - 500 - 250 - 125 - 62.5 mg a.i./kg DW for oats and 1000 - 333 - 111 - 37.0 - 12.3 - 4.11 - 1.37 - 0.457 mg a.i./kg DW for turnip.
The growth medium used was a 2:1 mixture of natural soil and sand.
The test item was incorporated into the soil once before the seeds were sown.
The rate of emergence was determined on day 7 and the plants were reduced to a maximum of 8 plants per replicate. At the first harvest (day 21) the plants were thinned out to 4 plants per replicate and the shoot height, the fresh weight and the number of buds and blossoms (turnip) of the harvested plants were determined.
At the definitive harvest (oats day 56, turnip day 42) the number of blossoms and husks, respectively, the shoot height, the biomass (fresh and dry weight) and the water content of the shoots, husks and blossoms, respectively, were determined.

Emergence
The % seedling emergence was not significantly affected in both species.

First Harvest
For both plant species no test item related visual phytotoxic effects occurred after 21 days.

Definitive Harvest
Oats: No significant effects were found on shoot height, shoot fresh weight, dry weight and water content of the shoots and blossom and the number of blossoms.
Turnip: No significant effect on shoot height, biomass as shoot fresh and dry weight of the shoots, husks, and water contents were found.
Significant effects were seen regarding the number of husks; the NOEC was determined to be 111 mg a.i/kg DW, with an EC50 of > 1000 mg a.i./kg DW.

Results Synopsis
Monocot
EC₅₀:     > 1000 mg a.i./kg DW.
NOEC:     1000 mg a.i./kg DW.

Dicot
EC₅₀:     > 1000 mg a.i./kg DW.
NOEC:     111 mg a.i/kg DW
Most sensitive parameter: number of husks

This toxicity study is classified as acceptable and satisfies the guideline requirement for a terrestrial plant chronic toxicity study.