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

Endpoint summary

Description of key information

Draft study report, OECD 222, (Eisenia fetida) were exposed to the test chemical at 0, 31.25, 62.5, 125, 250, 500, 1000 mg a.i./kg dry weight of artificial substrate for 8 weeks, not classified, Long-term NOEC = 250 mg/kg soil dw

 

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

 

Additional information

No final results for toxicity to soil macroorganisms except anthropods and 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.

 

 

 

In a 28 days toxicity and subsequent 8 weeks reproduction study, earthworms (Eisenia fetida) were exposed to the test chemical at 0, 31.25, 62.5, 125, 250, 500, 1000 mg a.i./kg dry weight of artificial substrate. The reference chemical used was Carbendazim at 0.5, 1, 2, 4 mg a.i./kg dw of the substrate. The experiment was carried out in accordance with OECD Test Guideline 222 (2016). The 28-day LC50 was ≥1000 mg a.i./kg dw of substrate. The 28-day EC50 was ≥ 1000 mg a.i./kg dw of substrate. The 28-day NOEC, based on mortality/biomass was ≥ 1000 mg a.i./kg dw of substrate. The LOEC, based on mortality/biomass was > 1000 mg a.i./kg dw of substrate.  The a.i. is considered to be non-toxic to earthworms up to a concentration of 1000 mg a.i./kg dw of substrate within 28 days.

The 8-week NOEC, based on reproduction was 250 mg i.a./kg SDW. The 8-week LOEC, based on reproduction was 500 mg i.a./kg SDW. The EC10 and EC50 value based on reproduction after 8 weeks were: 164 (97.0-278) and > 1000 (742->1000), respectively.

Under the conditions of this study, neither earthworm mortalities nor pathological symptoms or changes in the behaviour of adult earthworms were observed in the control and any test item concentration. Furthermore, no statistically significant differences in earthworm body weights were observed at any test item concentration compared to the control. After a further four weeks, the reproduction rate (average number of juveniles produced) was 82 in the control and ranged from 46 to 80 in the test item treatment rates. No statistically significant differences in earthworm reproduction were observed in the treatment rates 31.25 to 250 mg a.i./kg SDW compared to the control. However, at the test item concentrations 500 and 1000 mg a.i./kg SDW reproduction of earthworms was statistically significantly reduced.

 

This study is classified as acceptable and satisfies the guideline requirements for an 28-day/8-week reproduction toxicity study with earthworms according to OECD TG 222.

 

Results Synopsis

 

Test organism age (mean weight): between 0.36 and 0.51 g

 

Test Type:

28-day NOEC ≥ 1000 mg a.i./kg dw soil

8-week-NOEC =250 mg a.i./kg dw soil

8-week- EC50: > 1000 mg a.i./kg dw soil     95% CI: 742 to > 1000 mg a.i./kg dw soil

 

Endpoint(s) Effected: Mortality and reproduction

 

 

 

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.