Amides, C12-18 and C18-unsatd., N,N-bis(hydroxyethyl)

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Endpoint:

toxicity to terrestrial plants: short-term (with study design considered suitable for long-term assessment)

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

From February 13, 2020 to May 12, 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Refer to the section 13 for details on the category justification.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 208 (Terrestrial Plants, Growth Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

The test substance was suspended in ultrapure water at concentrations sufficient for the preparation of adequate test concentrations in soil (results of range-finding test 1 and 2, non-GLP). Prior to test start, the application solution of the highest test concentration was prepared by
suspending 51336 mg (target 51330 mg) of the test substance in 1000 mL of ultrapure water (main test 1) and 49253.58 mg (target: 49252 mg) of the test substance in 1300 mL of ultrapure water (main test 2). The application solutions of the lower test concentrations were prepared by diluting the application solution of the next higher concentration with appropriate volumes of purified water. For main test 1, 800 mL of application solution 1 was mixed with 41.064 kg dry soil (42.000 kg soil with residual moisture) for six species, 50 mL of application solutions 2-5 were mixed with 6.844 kg dry soil (7.000 kg soil with residual moisture) per treatment in the definitive test with tomato.
For main test 2, 800 mL of application solutions 1-5 were mixed with 30.309 kg dry soil (31.000 kg soil with residual moisture) per treatment with four species. The residual moisture of the soil substrate was determined to be 2.28%. The MWHC of the soil was 31.8%. In addition to the application solutions, adequate volumes of tap water was added to obtain the values of 30.1% of MWHC (main test 1) and 38.3% of MWHC. The moistened soil substrates were mixed by means of a laboratory mixer for five minutes to ensure homogenous distribution of the test substance and the additional water within the soil. The control treatment was prepared in the same way as the test substance treatments but without test substance. The moistening of the soil substrates was performed first with the control and then with the test substance treatments in ascending order. After filling the test units with test substrate, the seeds were sown. Afterwards, the pots were transferred to the greenhouse. Subsequently, the pots were irrigated with tap water.

Vehicle:

yes

Remarks:

Water

Details on preparation and application of test substrate:

Natural soil (Speyer 2.1) with an organic carbon content of 0.63% was used as test substrate for both main tests (Table 1). The soil was supplied by LUFA Speyer (67346 Speyer, Germany). The soil was not treated with any pesticide or organic fertiliser for four years prior to use. Before use, the soil was stored at IES Ltd. in plastic bags under ambient room conditions.
The test substance was suspended in ultrapure water at concentrations sufficient for the preparation of adequate test concentrations in soil. Prior to test start, the application solution of the highest test concentration was prepared by suspending 51336 mg (target 51330 mg) of the test substance in 1000 mL of ultrapure water (main test 1) and 49253.58 mg (target: 49252 mg) of the test substance in 1300 mL of ultrapure water (main test 2). The application solutions of the lower test concentrations were prepared by diluting the application solution of the next higher concentration with appropriate volumes of purified water.
For main test 1, 800 mL of application solution 1 was mixed with 41.064 kg dry soil (42.000 kg soil with residual moisture) for six species, 50 mL of application solutions 2-5 were mixed with 6.844 kg dry soil (7.000 kg soil with residual moisture) per treatment in the definitive test with tomato. For main test 2, 800 mL of application solutions 1-5 were mixed with 30.309 kg dry soil (31.000 kg soil with residual moisture) per treatment with four species. The residual moisture of the soil substrate was determined to be 2.28%. The MWHC of the soil was 31.8%. In addition to the application solutions, adequate volumes of tap water were added to obtain the values of 30.1% of MWHC and 38.3% of MWHC. The moistened soil substrates were mixed by means of a laboratory mixer for five minutes to ensure homogenous distribution of the test substance and the additional water within the soil. The control treatment was prepared in the same way as the test substance treatments but without test substance.
The moistening of the soil substrates was performed first with the control and then with the test substance treatments in ascending order. After filling the test units with test substrate, the seeds were sown. Afterwards, the pots were transferred to the greenhouse. Subsequently, the pots were irrigated with tap water from below.

Species:

Lycopersicon esculentum

Plant group:

Dicotyledonae (dicots)

Species:

Brassica napus

Plant group:

Dicotyledonae (dicots)

Species:

other: Fagopyrum esculentum

Plant group:

Dicotyledonae (dicots)

Species:

Phaseolus vulgaris

Plant group:

Dicotyledonae (dicots)

Species:

Hordeum vulgare

Plant group:

Monocotyledonae (monocots)

Species:

Allium cepa

Plant group:

Monocotyledonae (monocots)

Test type:

seedling emergence and seedling growth test

Study type:

laboratory study

Substrate type:

natural soil

Limit test:

no

Total exposure duration:

21 d

Test temperature:

- Main test 1 (barley, onion, bean, buckwheat, oilseed-rape, tomato):
Temperature: 9.4 – 27.2°C with a mean of 19.0°C. Temperature was a few times below 12°C. Deviations from the recommended range of temperature conditions (i.e. 22 ± 10°C in the greenhouse) are not considered to impact the outcome of the study since growth of control plants was normal.

- Main test 2 (barley, bean, buckwheat, oilseed rape):
Temperature: 18.1 – 28.8°C with a mean of 22.5°C. No deviations from the recommended range of temperature conditions (i.e. 22 ± 10°C in the greenhouse) were observed.

pH:

pH 4.7 ± 0.01

Moisture:

- Main test 1: Relative humidity: 47.2 – 77.4% with a mean of 61.0%.

- Main test 2: Relative humidity: 47.0 – 75.5% with a mean of 59.7%.

Details on test conditions:

The pots with the sown seeds and the emerged test plants were kept in the greenhouse at IES Ltd (4108 Witterswil/Switzerland). In the greenhouse, an area of approx. 12 m2 was used for this study. The environmental conditions were continually recorded by a data-logger. Temperature and relative humidity in the greenhouse were set at 22 ± 10°C and 70 ± 25%, respectively. A light-dark cycle of 16 hours light and 8 hours darkness was maintained. Light measurements took place several times during the test taking into account shady and sunny points. The treatment groups were rotated at each observation time to ensure a uniform light regime for all plants. The plant pots with the seeds and the later emerging plants were watered with local tap water using bottom irrigation. No additional nutrients were applied. According to the soil analysis the pH was 4.7. No further determination of pH was conducted. The maximum water holding capacity (MWHC) of the soil was 31.8 g/100 g dry soil. The soil water content at test start were adjusted to 30.1% and 38.3% of MWHC for main test 1 and 2, respectively.
Six plant species were tested. Based on the results of range-finding test 1 and 2, five limit tests (barley, onion, bean, buckwheat, oilseed rape) and one definitive test (tomato) were performed. Since in main test 1 the emergence of barley was not sufficient and effects were observed in the limit test with bean, buckwheat and oilseed rape, the study was repeated as main test 2 with four definitive tests (barley, bean, buckwheat and oilseed rape). The tests were performed in a randomized design with 20 replicates per treatment. 20 seeds were sown per treatment and plant species after the soil application (i.e. 1 seed per pot). The number of seeds per pot allowed unrestricted growth of the selected species. The seeds were not imbibed with water. The test substance was prepared by suspending the test substancein water. Afterwards, the application solution was mixed with the soil before the seeds were sown. The test duration was 21 days after emergence of 50% in the control for all test species (as requested by the guideline). The test concentrations were chosen in consultation with the Sponsor based on the results of range-finding tests. The test substance was tested at the following test concentrations:
- Main test 1: Limit tests with 1000 mg/kg/dry soil (barley, onion, bean, buckwheat, oilseed rape) Definitive test with 10, 32, 100, 320 and 1000 mg/kg dry soil (tomato)
- Main test 2: Definitive test with 10, 32, 100, 320 and 1000 mg/kg dry soil (barley, bean, buckwheat, and oilseed rape). Additionally, controls (plants treated in the same way as the test substance treatment but without test substance were tested in parallel.

Experimental Evaluations:
The plants were observed once a week for emergence, visual phytotoxicity (i.e. leaf and stem deformations, chlorosis, necrosis and overall appearance compared with the control) and mortality of emerged plants. At the end of the test, the final fresh weight and the final shoot length were determined. The observation period started as soon as 50% of the seedlings had emerged in the control. The number of emerged plants was observed weekly for the 21-day test duration period. Phytotoxicity was evaluated visually by using a scoring system for visual effects of the plants (scale 0 to 3 depending on the severity of damage):
• 0 (no symptoms): 0% of leaf area damaged,
• 1 (slight symptoms): ≤ 25% of leaf area damaged,
• 2 (moderate symptoms): 25-75% of leaf area damaged,
• 3 (severe symptoms): ≥ 75% of area leaf damaged.
The plants were cut directly between root and shoot. For that purpose, each plant was pulled slightly out of the soil to uncover the site of cutting. The fresh weight of the cut plants was determined directly after determination of the plant length.

Nominal and measured concentrations:

In main test 1, the nominal concentration of the test substance prepared in the application solution of the highest test concentration was 51.3 mg/mL.

Reference substance (positive control):

no

Key result

Species:

Lycopersicon esculentum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Fresh weight

Key result

Species:

Lycopersicon esculentum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Shoot height

Key result

Species:

Lycopersicon esculentum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Survival

Key result

Species:

Lycopersicon esculentum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Key result

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

320 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Fresh weight

Key result

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

320 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Shoot height

Key result

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Survival

Key result

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

320 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Key result

Species:

other: Fagopyrum esculentum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Survival

Key result

Species:

other: Fagopyrum esculentum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

320 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Fresh weight

Key result

Species:

other: Fagopyrum esculentum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

320 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Shoot height

Key result

Species:

other: Fagopyrum esculentum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Key result

Species:

Phaseolus vulgaris

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Shoot height

Key result

Species:

Phaseolus vulgaris

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Fresh weight

Key result

Species:

Phaseolus vulgaris

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Survival

Key result

Species:

Phaseolus vulgaris

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

320 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Key result

Species:

Allium cepa

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Fresh weight

Key result

Species:

Allium cepa

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Shoot height

Key result

Species:

Allium cepa

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Survival

Key result

Species:

Allium cepa

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Key result

Species:

Hordeum vulgare

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Fresh weight

Key result

Species:

Hordeum vulgare

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Shoot height

Key result

Species:

Hordeum vulgare

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Survival

Key result

Species:

Hordeum vulgare

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Details on results:

Barley (Hordeum vulgare): In main test 1, emergence rate of barley was 0% in the control and in the limit test treatment with 1000 mg/kg dry soil due to insufficient quality of the seeds. In main test 2, emergence rate of barley was 95% in the control and 95-100% in the test substanec treatments without a concentration-effect relationship and without a statistically significant difference compared to the control (multiple sequentially Fisher test after Bonferroni-Holm, one-sided greater, α = 0.05. No symptoms of toxicity were observed in the control and in the test substance treatments.
Mortality of emerged barley plants was 0% in the control and 0-5 % in the test substance treatments without a concentration-effect relationship and without a statistically significant difference compared to the control (multiple sequentially Fisher test after Bonferroni-Holm, one-sided greater, α = 0.05). The mean shoot length was 28.0 cm/plant in the control and in the test substance treatments 109- 126% of the control. No statistical analysis was necessary since the values of all test substance treatments up to and including the highest test concentration of 1000 mg/kg dry soil were not smaller than in the control. The mean fresh weight per replicate in the control was 750 mg/replicate and in the test substance treatments 112-175% of the control. No statistical analysis was necessary since the values of all test substance treatments up to and including the highest test concentration of 1000 mg/kg dry soil were not smaller than in the control.
Onion (Allium cepa): In main test 1, the emergence rate of onion was 75% in the control and 90% in the limit test substance treatment of 1000 mg/kg dry soil. No statistical analysis was necessary since the value in the limit test substance treatment of 1000 mg/kg dry soil was not smaller than in the control. No symptoms of toxicity and no mortality were observed in the control and in the limit test substance treatment of 1000 mg/kg dry soil. The mean shoot length was 9.0 cm/replicate in the control and 10.0 cm/replicate in the limit test substance treatment of 1000 mg/kg dry soil. No statistical analysis was necessary since the value of in the limit test substance treatment of 1000 mg/kg dry soil was not smaller than the control. The mean fresh weight was 47.2 mg/replicate in the control and 123% of the control in the limit test substance treatment of 1000 mg/kg dry soil. No statistical analysis was necessary since the value of in the limit test substance treatment of 1000 mg/kg dry soil was not smaller than in the control.
Bean (Phaseolus vulgaris): In main test 1, the emergence rate of bean was 90% in the control and 75% in the limit test substance treatment of 1000 mg/kg dry soil without a statistically significant difference compared to the control (Fisher exact test, one-sided greater, α = 0.05; Table 3). No symptoms of toxicity and no mortality were observed in the control and in the limit test substance treatment of 1000 mg/kg dry soil. The mean shoot length was 11.0 cm/replicate in the control and 95% of the control in the the limit test substance treatment of 1000 mg/kg dry soil without a statistically significant difference compared to the control (Student t-test, one-sided smaller, α = 0.05). The mean fresh weight was 1069 mg/replicates in the control and 78% of the control in the limit test substance treatment of 1000 mg/kg dry soil with a statistically significant difference compared to the control (Student t-test, one-sided smaller, α = 0.05). In main test 2, the emergence rate of bean was 90% in the control and 95-100% in the substance treatments up to and including 320 mg/kg dry soil without a statistically significant difference compared to the control (multiple sequentially Fisher test after Bonferroni-Holm, one-sided greater, α = 0.05). The emergence at the highest test concentration of 1000 mg/kg dry soil was 50% and statistically significantly smaller than the control. No symptoms of toxicity and no mortality were observed in the control and in all test substance treatments up to and including 1000 mg/kg dry soil. The mean shoot length was 14.2 cm/replicate in the control and 98-121% of the control in the test substance treatments without a concentration-effect relationship and without a statistically significant difference compared to the control (Dunnett t-test, one-sided smaller, α = 0.05; Table 13). The mean fresh weight was 1324 mg/replicate in the control and 110-143% of the control in the test substance treatments. No statistical analysis was necessary since the values in all test substance treatments up to and including 1000 mg/kg dry soil were not smaller than in the control.
Buckwheat (Fagopyrum esculentum): In main test 1, the emergence rate of buckwheat was 100% in the control and 95% in the limit test substance treatment of 1000 mg/kg dry soil without a statistically significant difference compared to the control (Fisher exact test, one-sided greater, α = 0.05). No symptoms of toxicity and no mortality were observed in the control and in the limit test substance treatment of 1000 mg/kg dry soil. The mean shoot length was 30.9 cm/replicate in the control and 52% of the control in the the limit test substance treatment of 1000 mg/kg dry soil with a statistically significant difference compared to the control (Student t-test, one-sided smaller, α = 0.05). The mean fresh weight was 1238 mg/replicates in the control and 59% of the control in the limit test substance treatment of 1000 mg/kg dry soil with a statistically significant difference compared to the control (Student t-test, one-sided smaller, α = 0.05). In main test 2, the emergence rate of buckwheat was 100% in the control and 95-100% in the substance treatments without a statistically significant difference compared to the control (multiple sequentially Fisher test after Bonferroni-Holm, one-sided greater, α = 0.05). No symptoms of toxicity and no mortality were observed in the control and in all test substance treatments up to and including 1000 mg/kg dry soil. The mean shoot length was 40.9 cm/replicate in the control and 108-129% of the control in the test substance treatments up to and including 320 mg/kg dry soil without a statistically significant difference compared to the control (Williams t-test, one-sided smaller, =0.05). Shoot length at 1000 mg/kg dry soil was 62% of the control and statistically significantly smaller than the control. The mean fresh weight was 1971 mg/replicate in the control and 119-133% of the control in the test substance treatments up to and including 320 mg/kg dry soil without a statistically significant difference compared to the control (Williams t-test, one-sided smaller, =0.05). Fresh weight at 1000 mg/kg dry soil was 71% of the control and statistically significantly smaller than the control.
Oilseed-rape (Brassica napus): In main test 1, the emergence rate of oilseed rape was 95% both in the control and in the limit test substance treatment with 1000 mg/kg dry soil. No symptoms of toxicity and no mortality were observed in the control and in the limit test substance treatment of 1000 mg/kg dry soil. The mean shoot length was 12.3 cm/replicate in the control and 35% of the control in the limit test substance concentration of 1000 mg/kg dry soil with a statistically significant difference compared to the control (Student t-test, one-sided smaller, =0.05). The mean fresh weight was 448 g/replicate in the control and 23% of the control in the limit test substance concentration of 1000 mg/kg dry soil with a statistically significant difference compared to the control (Welch t-test for inhomogeneous variances, one-sided smaller, =0.05). In main test 2, the emergence rate of oilseed rape was 100% in the control and 95-100% in the substance treatments up to and including 320 mg/kg dry soil without a statistically significant difference compared to the control (multiple sequentially Fisher test after Bonferroni-Holm, one-sided greater, α = 0.05). Emergence rate at 1000 mg/kg dry soil was 30% and was statistically significantly smaller than the control. No symptoms of toxicity were observed in the control and in all test item treatments up to and including 1000 mg/kg dry soil.
Mortality of emerged oilseed rape plants was 0% in the control and in all test substance treatments up to and including 320 mg/kg dry soil. At 1000 mg/kg dry soil, one of six emerged plants died, mortality was not statistically significantly different from the control (multiple sequentially Fisher test after Bonferroni-Holm, one-sided greater, α = 0.05). The mean shoot length was 25.7 cm/replicate in the control and 102-142% of the control in the test substance treatments up to and including 320 mg/kg dry soil without a statistically significant difference compared to the control (Williams t-test, one-sided smaller, =0.05). Shoot length at 1000 mg/kg dry soil was 28% of the control and statistically significantly smaller than the control. The mean fresh weight was 906 mg/replicate in the control and 106-267% of the control in the test substance treatments up to and including 320 mg/kg dry soil without a statistically significant difference compared to the control (Williams t-test, one-sided smaller, =0.05). Fresh weight at 1000 mg/kg dry soil was 37% of the control and statistically significantly smaller than the control.
Tomato (Lycopersicon esculentum): In main test 1, the emergence rate of tomato was 75% in the control and 65-85% in the substance treatments without a concentration-effect relationship and without a statistically significant difference compared to the control (multiple sequentially Fisher test after Bonferroni-Holm, one-sided greater, α = 0.05). No symptoms of toxicity and no mortality were observed in the control and in all test substance treatments up to and including 1000 mg/kg dry soil. The mean shoot length was 5.6 cm/replicate in the control and 101-156% of the control in the test substance treatments. No statistical analysis was necessary since the values in all test substance treatments up to and including 1000 mg/kg dry soil were not smaller than in the control. The mean fresh weight was 122 mg/replicate in the control and 114-368% of the control in the test substance. No statistical analysis was necessary since the values in all test item treatments up to and including 1000 mg/kg dry soil were not smaller than in the control.

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the test substance reduced the emergence rate of two plant species (bean and oilseed rape) at 1000 mg/kg dry soil and had no effects on survival of the emerged plants up to and including the highest test substance concentration of 1000 mg/kg dry soil for all six tested plant species. Growth of two species (buckwheath, oil seed rape) was reduced at 1000 mg/kg dry soil. The overall NOEC was determined to be 320 mg/kg dry soil. The lowest EC10 and EC20 were 232 and 350 mg/kg dry soil based on effects on shoot length of oilseed rape. The lowest LC50 was > 1000 mg/kg dry soil (all species). The lowest EC50 for emergence, shoot length and fresh weight were 633 mg/kg dry soil (oilseed rape), 768 mg/kg dry soil (oilseed rape) and > 1000 mg/kg dry soil (all species), respectively.

Executive summary:

A study was conducted to determine the effects on terrestrial (non-target) plants of the read across substance C8-18 and C18-unsatd. DEA, according to OECD Guideline 208, in compliance with GLP. Seeds of six plant species were sown in natural soil treated with the test substance in two main tests. The experiments were repeated in main test 2 with four species due to invalid emergence (bean) and effects at the limit test concentration (barley, buckwheat, onion) in main test 1. The test substance concentration was 1000 mg/kg dry soil (Limit tests in main test 1) and 10, 32, 100, 320 and 1000 mg/kg dry soil (Definitive tests in main test 1 and 2). Application solutions for the different test concentrations were prepared by dispersing the test substance in ultrapure water and then thoroughly mixed with the soil substrate before the seeds were sown. The study consisted of one test with five test substance concentrations (tomato) and five tests with one limit test concentration (barley, bean, buckwheat, oilseed rape, onion) in main test 1 and four tests with five test substance concentrations (barley, bean, buckwheat, onion) in main test 2. 20 replicates per treatment, each containing one seed, were set up. A water control was performed in parallel. Emergence of plants from seeds and mortality and symptoms of toxicity of emerged plants were assessed during the study. Plant fresh weight and shoot length were determined at test end, 21 days after 50% of the control plants had emerged. Under the study conditions, the test substance reduced the emergence rate of two plant species (bean and oilseed rape) at 1000 mg/kg dry soil and had no effects on survival of the emerged plants up to and including the highest test substance concentration of 1000 mg/kg dry soil for all six tested plant species. Growth of two species (buckwheath, oil seed rape) was reduced at 1000 mg/kg dry soil. The overall NOEC was determined to be 320 mg/kg dry soil. The lowest EC10 and EC20 were 232 and 350 mg/kg dry soil based on effects on shoot length of oilseed rape. The lowest LC50 was > 1000 mg/kg dry soil (all species). The lowest EC50 for emergence, shoot length and fresh weight were 633 mg/kg dry soil (oilseed rape), 768 mg/kg dry soil (oilseed rape) and > 1000 mg/kg dry soil (all species), respectively (Schmidt, 2021).

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:

320 mg/kg soil dw

Additional information

A study was conducted to determine the effects on terrestrial (non-target) plants of the read across substance C8-18 and C18-unsatd. DEA, according to OECD Guideline 208, in compliance with GLP. Seeds of six plant species were sown in natural soil treated with the test substance in two main tests. The experiments were repeated in main test 2 with four species due to invalid emergence (bean) and effects at the limit test concentration (barley, buckwheat, onion) in main test 1. The test substance concentration was 1000 mg/kg dry soil (Limit tests in main test 1) and 10, 32, 100, 320 and 1000 mg/kg dry soil (Definitive tests in main test 1 and 2). Application solutions for the different test concentrations were prepared by dispersing the test substance in ultrapure water and then thoroughly mixed with the soil substrate before the seeds were sown. The study consisted of one test with five test substance concentrations (tomato) and five tests with one limit test concentration (barley, bean, buckwheat, oilseed rape, onion) in main test 1 and four tests with five test substance concentrations (barley, bean, buckwheat, onion) in main test 2. 20 replicates per treatment, each containing one seed, were set up. A water control was performed in parallel. Emergence of plants from seeds and mortality and symptoms of toxicity of emerged plants were assessed during the study. Plant fresh weight and shoot length were determined at test end, 21 days after 50% of the control plants had emerged. Under the study conditions, the test substance reduced the emergence rate of two plant species (bean and oilseed rape) at 1000 mg/kg dry soil and had no effects on survival of the emerged plants up to and including the highest test substance concentration of 1000 mg/kg dry soil for all six tested plant species. Growth of two species (buckwheath, oil seed rape) was reduced at 1000 mg/kg dry soil. The overall NOEC was determined to be 320 mg/kg dry soil. The lowest EC10 and EC20 were 232 and 350 mg/kg dry soil based on effects on shoot length of oilseed rape. The lowest LC50 was > 1000 mg/kg dry soil (all species). The lowest EC50 for emergence, shoot length and fresh weight were 633 mg/kg dry soil (oilseed rape), 768 mg/kg dry soil (oilseed rape) and > 1000 mg/kg dry soil (all species), respectively (Schmidt, 2021).