A mixture of: 2-ethylhexyl mono-D-glucopyranoside; 2-ethylhexyl di-D-glucopyranoside

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:

September 2015- January 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Study

Qualifier:

according to guideline

Guideline:

OECD Guideline 208 (Terrestrial Plants Test: Seedling Emergence and Seedling Growth Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES

- Water solubility (under test conditions): Soluble in cold water

Analytical monitoring:

no

Details on preparation and application of test substrate:

The studies were performed using a natural soil LUFA 2.3 (Sandy Loam), purchased from Landwirtschaftliche Untersuchungs und Forschungsanstalt (Germany) sieved at 2 mm. The substrate has the following characteristics:
pH (KCl): 6.9
Water holding capacity: 29 %
Percentage of organic carbon: 0.55 %


The day before adding seeds, a stock solution of the test item was prepared at 10 g/L in deionised water.The test item concentrations in soil were achieved by adding, in the required mass of natural soil, the corresponding volume of test item stock solution at 10g/L and a sufficient volume deionised water to reach a soil moisture around 11%. The test preparation was mixed in the soil for 5 minutes with a laboratory mixer.
After seeds sowing, the final moisture content was then adjusted by adding remaining required dechlorinated water by capillarity from the bottom of the pot.

Species:

other: See tables 1 and 2 for test species description

Test type:

early seedling growth toxicity test

Study type:

laboratory study

Substrate type:

natural soil

Total exposure duration:

19 d

Post exposure observation period:

NO

Test temperature:

Light period : 24± 3°C
Dark period: 20 ±3°C

pH:

See Tables 3 to 4 for details of pH values at the preparation day and at the end of exposure

Moisture:

70% of soil water holding capacity
See Tables 3 to 4 for details of moisture content values at the preparation day and at the end of exposure

Details on test conditions:

TEST SYSTEM
- Testing facility: Climatic Chambers (Phytotron)

- Test container (type, material, size): Plastic plant pots (85 mm diameter, 110 mm height)

- Amount of soil: 330g dry weight

- No. of seeds per container:
6 for turnip, cress, radish, wheat, barley
4 for garden bean

- No. of plants (retained after thinning): no thinning

- No. of replicates per treatment group and per control
6 for turnip, cress, radish, wheat, barley
8 for garden bean


SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Geographic location: Germany

- Pesticide use history at the collection site: none since 5 formers years

- Sampling depth (cm): 20

- Soil taxonomic classification: Sandy loam

- Soil classification system: USDA %

- Maximum water holding capacity (in % dry weigth): 29%

- Pretreatment of soil (immediatly after sampling):
dried 1 day at room temperature
sieved at 2mm

- Storage (condition, duration):
5 months in open bags allowing gas exchange, at room temperature


GROWTH CONDITIONS
- Photoperiod: 16h light / 8h dark

- Light source:
neons tubes for plant growth

- Light intensity and quality:
13 000 ± 3 000 Lux
220.0 ± 50.0 PAR

- Day/night temperatures:
Light period : 24± 3°C
Dark period: 20 ±3°C

- Relative humidity (%):
45 - 65 % in the climatic chamber

- Watering regime and schedules:
Soil moisture was maintained constant around 70 % of soil water holding capacity by weighting pots and replenishing with dechlorinated water at least three times per week.

- Method of application:
Replenish by the bottom of the pot


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

number emerged seedlings
final biomass (plant dry weight),
visible detrimental effects on different parts of the plants.

Nominal and measured concentrations:

Nominal concentrations:
study 15-005-155277 : 195.3 – 312.5 – 500.0 – 800.0 mg/kg soil dw
study 15-009-155277 : 68.7 – 109.9 – 175.8 – 281.3 – 450.0 mg/kg soil dw

Reference substance (positive control):

no

Species:

Phaseolus vulgaris

Duration:

19 d

Dose descriptor:

NOEC

Effect conc.:

>= 800 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: study 15-005-155277

Key result

Species:

Lepidum sativum

Duration:

19 d

Dose descriptor:

NOEC

Effect conc.:

195.3 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: study 15-005-155277

Species:

Lepidum sativum

Duration:

19 d

Dose descriptor:

LOEC

Effect conc.:

312.5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: study 15-005-155277

Species:

Raphanus sativus

Duration:

19 d

Dose descriptor:

NOEC

Effect conc.:

500 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: study 15-005-155277

Species:

Raphanus sativus

Duration:

19 d

Dose descriptor:

LOEC

Effect conc.:

800 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: study 15-005-155277

Key result

Species:

Triticum aestivum

Duration:

18 d

Dose descriptor:

NOEC

Effect conc.:

195.3 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: study 15-005-155277

Species:

Triticum aestivum

Duration:

18 d

Dose descriptor:

LOEC

Effect conc.:

312.5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: study 15-005-155277

Species:

Brassica rapa

Duration:

19 d

Dose descriptor:

NOEC

Effect conc.:

>= 800 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: study 15-005-155277

Species:

Brassica rapa

Duration:

19 d

Dose descriptor:

NOEC

Effect conc.:

>= 450 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: study 15-009-155277

Species:

Hordeum vulgare

Duration:

18 d

Dose descriptor:

NOEC

Effect conc.:

312.5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: study 15-005-155277

Species:

Hordeum vulgare

Duration:

18 d

Dose descriptor:

LOEC

Effect conc.:

500 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: study 15-005-155277

Species:

Hordeum vulgare

Duration:

18 d

Dose descriptor:

NOEC

Effect conc.:

281.3 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: study 15-009-155277

Species:

Hordeum vulgare

Duration:

18 d

Dose descriptor:

LOEC

Effect conc.:

450 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: study 15-009-155277

Species:

Phaseolus vulgaris

Duration:

19 d

Dose descriptor:

NOEC

Effect conc.:

500 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other: study 15-005-155277

Species:

Phaseolus vulgaris

Duration:

19 d

Dose descriptor:

LOEC

Effect conc.:

800 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other: study 15-005-155277

Key result

Species:

Lepidum sativum

Duration:

19 d

Dose descriptor:

NOEC

Effect conc.:

195.3 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other: study 15-005-155277

Species:

Lepidum sativum

Duration:

19 d

Dose descriptor:

LOEC

Effect conc.:

312.5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other: study 15-005-155277

Key result

Species:

Raphanus sativus

Duration:

19 d

Dose descriptor:

NOEC

Effect conc.:

195.3 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other: study 15-005-155277

Species:

Raphanus sativus

Duration:

19 d

Dose descriptor:

LOEC

Effect conc.:

312.5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other: study 15-005-155277

Key result

Species:

Triticum aestivum

Duration:

18 d

Dose descriptor:

NOEC

Effect conc.:

195.3 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other: study 15-005-155277

Species:

Triticum aestivum

Duration:

18 d

Dose descriptor:

LOEC

Effect conc.:

312.5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other: study 15-005-155277

Species:

Brassica rapa

Duration:

19 d

Dose descriptor:

NOEC

Effect conc.:

>= 450 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other: study 15-009-155277

Species:

Hordeum vulgare

Duration:

18 d

Dose descriptor:

NOEC

Effect conc.:

175.8 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other: study 15-009-155277

Species:

Hordeum vulgare

Duration:

18 d

Dose descriptor:

LOEC

Effect conc.:

281.3 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other: study 15-009-155277

Details on results:

SEEDLING EMERGENCE
- Percent seedling emergence: see tables 5 and 6.

Study 15-005-155277

No emergence was observed at 800.0 mg/ kg for cress, wheat and barley at the end of the test .

A statistically significant effect of the test item was measured on emergence at:
- 312.5 mg/kg soil dry mass for cress and wheat
- 500 mg/kg soil dry mass for barley
Not significant effect were observed for garden bean and turnip at the highest tested concentration.


Delay in the first day of cotyledon/coleoptyl appearance and emergence rate in test concentrations compare to control conditions:

- At the lowest test concentration (195.3 mg/kg soil dw), cotyledon appearences were delayed for turnip (1 day) and cress (2 days). For wheat, the number of emerged seedling was also lower during the first days compare to control.
No emergence inhibition was observed for any species at the end of the test period.

- At 312.5 mg/kg soil dw delays in the first day of cotyledon/ coleopty appearence were observed (1 to 4 days) for the six species
A significant inhibition of emergence for cress (29.0%) and wheat (31.4%) was observed at the end of the exposure period.

-At 500 mg/kg soil dw, delays in the first day of cotyledon/ coleopty appearence were observed for the six species (3 to 10 days)
A significant inhibition of emergence was observed at the end of the test for cress (71.0%), wheat (94.3%) and barley (80.6%).

Study 15-009-155277
- At 175.8 mg/kg soil dw, no delays in date of cotyledon/ coleopty appearence, compared to control were observed for the two species
No emergence inhibition was observed for any species at the end of the test period.

- At 281 mg/kg soil dw no delay in t in date of cotyledon/ coleopty appearence, compared to control were observed for the two species
No significant inhibition of emergence was observed for any species at the end of the test period

-At 450 mg/kg soil dw no emergence was observed for barley

At the end of the exposure, no statistically significant effect of the test item was measured on emergence for turnip for all concentrations and for barley for concentrations except at 450 mg/kg soil dw.

Comparing the two studies, it can be noticed that, for turnip, the duration to reach 60% of emergence was longer in the first study than in the second, for comparable concentrations:

Study 1 at 195.3 mg/kgsoil dw : day 3 : 0 %; day 4 : 77.8 %; day 5: 86.1%, day 7: 91.7 % (emergengence in controls : 88.9 % at day 3)
Study 2 at 175.8 mg/kg soil dw : day 3: 66.7 %; day 4: 80.6 %; day 5: 80.6 %, day 7 : 86.1% (emergengence in controls : 88.9 % at day 3)

Study 1 at 500 mg/kg soil dw : day 3 : 0 %; day 4 : 0 %; day 5 : 0%; day 7: 55.6 % (emergengence in controls : 88.9 % at day 3)
Study 2 at 450 mg/kgsoil dw : day 3: 0 %; day 4: 25 %; day 5: 83.3 %; day 7 : 86.1% (emergengence in controls : 94.4 % at day 3)


- Percent of survivalof emerged seedlings in the controls:
study 15-005-155277 : 96.8% – 100%
study 15-009-155277 : 100 %



Visual observation of seedlings

Study 15-005-155277

-No significant phytotoxic effect in control conditions and in test concentration unless for barley at 312.5 mg/kg soil dw for which necrosis of leaves (1 to 5 cm) was noticed on six plants on thirty three.
-For dicotyledoneous species, an effect on plant development stage (number of leaves) for cress from 312.5 mg/kg soil dw ( 13-14, 15-16 in controls) and turnip at 800.0 mg/kg soil dry mass ( 12, 14 in controls) .
-For monocotyledoneous species, a diminution of shoot heights at 312.5 mg/kg soil dw (min-max: 3.5-17.7 cm, min-max controls: 13.7-23.0 cm) for wheat.

Study 15-009-155277

-No significant phytotoxic effect in control conditions for the two tested species,
-For barley, at 281.3 mg/kg soil dw, necrosis of leaves (1 to 5 cm) was noticed for five plants on twenty eight,
-No effect of concentration on shoots height and on plant development stage compared to control conditions.



Effect on biomass :

See tables 7 and 8

Reported statistics and error estimates:

Statistics were performed using Toxstat 3.5, Western Inc. and D. Gulley, University of Wyoming.
Emergence:
Normality and homogeneity of the data were verified and the significativity of the effect on emergence was considered, by performing
- a one-way ANOVA (α-value = 0.05) followed by the Dunett’s post-hoc t-test (α value = 0.05), for data normally distributed
- a Kruskall –Wallis ANOVA by ranks (α value = 0.05), followed by a Dunn’s multiple comparison (α value = 0.05).
Growth
Normality and homogeneity of the data were verified and the significativity of the effect on growth was considered, by performing a one-way ANOVA (α-value = 0.05) followed by the Dunett’s post-hoc t-test (α-value = 0.05, identical number of replicates) or a by the Bonferroni post-hoc t-test (α-value = 0.05, different number of replicates).

Table 5 : Seedling emergence at day 7 and at the end of exposure period; study 15 -007 -155277

Nominal test concentration (in mg/kg soil dry weight)	Seedling emergence in % (total of emerged plants per test concentration)
	Observation day	Control	195.3	312.5	500.0	800.0
Turnip (36 seeds)	7	91.7 (33)	91.7 (33)	91.7 (33)	55.6 (20)	0 (0)
	19	91.7 (33)	91.7 (33)	91.7 (33)	88.9 (32)	80.6 (29)
Garden bean (32 seeds)	7	90.6 (29)	90.6 (29)	87.5 (28)	78.1 (25)	34.4 (11)
	19	90.6 (29)	90.6 (29)	87.5 (28)	87.5 (28)	65.6 (21)
Cress (36 seeds)	7	86.1 (31)	83.3 (30)	13.9 (5)	0 (0)	0 (0)
	19	86.1 (31)	88.9 (32)	61.1 (22)	25.0 (9)	0 (0)
Radish (36 seeds)	7	88.9 (32)	97.2 (35)	97.2 (35)	80.6 (29)	2.8 (1)
	19	88.9 (32)	97.2 (35)	97.2 (35)	97.2 (35)	52.8 (19)
Wheat (36 seeds)	7	97.2 (35)	100 (36)	63.9 (23)	0 (0)	0 (0)
	18	97.2 (35)	100 (36)	66.7 (24)	5.6 (2)	0 (0)
Barley (36 seeds)	7	100 (36)	100 (36)	91.7 (33)	16.7 (6)	0 (0)
	18	100 (36)	100 (36)	91.7 (33)	19.4 (7)	0 (0)

Table 6: Seedling emergence at day 7 and at the end of exposure period; study 15 -009 -155277

Nominal test concentration (in mg/kg soil dry weight)	Seedling emergence in % (total of emerged plants per test concentration)
	Observation day	Control	68.7	109.9	175.8	281.3	450.0
Turnip (36 seeds)	7	94.4 (34)	86.1 (31)	100 (36)	80.6 (29)	88.9 (32)	86.1 (31)
	19	94.4 (34)	86.1 (31)	100 (36)	80.6 (29)	88.9 (32)	86.1 (31)
Barley (36 seeds)	7	88.9 (32)	94.4 (34)	94.4 (34)	97.2 (35)	77.8 (28)	0 (0)
	18	88.9 (32)	94.4 (34)	94.4 (34)	97.2 (35)	77.8 (28)	0 (0)

Table 7 : Mean biomass of seedlings (dry mass) and growth inhibition calculation; study 15 -005 -155277

	Nominal test concentration (in mg/kg soil dry weight)	Number of emerged seeds	Number of harvested plants	Mean biomass (mg) CV %	Growth inhibition
Turnip	Controls	33	33	227.54 19.4	/
	195.3	33	33	163.22 21.0	28.27*
	312.5	33	33	124.29 15.0	45.38*
	500.0	32	32	96.73 17.3	57.49*
	800.0	29	29	25.24 65.9	88.91*
Garden bean	Controls	29	29	1206.71 16.7	/
	195.3	29	29	1136.83 13.0	5.79
	312.5	28	28	1180.73 23.7	2.15
	500.0	28	28	1155.95 20.0	4.21
	800.0	21	20	764.55 39	36.64*
Cress	Controls	31	29	65.96 27.3	/
	195.3	32	32	49.76 34.7	24.56
	312.5	22	22	24.06 30.1	63.52*
	500.0	9	9	1.91 69.4	97.10*
	800.0	0	0	/ /	100*
Radish	Controls	32	32	285.26 13.6	/
	195.3	35	35	259.00 7.8	9.20
	312.5	35	35	209.93 12.6	26.41*
	500.0	35	35	170.33 10.0	40.29*
	800.0	19	19	70.97 36.7	75.12*
Wheat	Controls	35	35	255.61 21.7	/
	195.3	36	35	215.25 16.2	15.79
	312.5	24	23	34.55 53.95	86.49 *
	500.0	2	2	2.82 /	98.90 *
	800.0	0	0	/ /	100*
Barley	Controls	36	36	338.11 9.08	/
	195.3	36	36	283.22 9.6	16.24*
	312.5	33	33	196.85 15.3	41.78*
	500.0	7	6	25.55 99.7	92.44*
	800.0	0	0	/ /	100*

*Inhibtion statistically significant (Dunett’s or Bonferroni test; α=0.05)

Table 8 : Mean biomass (dry mass) of seedlings and growth inhibtion calculation

	Test item concentration (in mg/kg soil dry weight)	Number of emerged seeds	Number of harvested plants	Mean biomass (mg) CV %	Growth inhibition (%)
Turnip	Controls	34	34	262.38 14.6	/
	68.7	31	31	287.98 19.6	-9.76
	109.9	36	36	245.10 23.6	6.59
	175.8	29	29	195.33 20.1	25.55*
	281.3	32	32	215.82 24.9	17.75
	450.0	31	31	199.32 20.2	24.04
Barley	Controls	32	32	425.73 16.7	/
	68.7	34	34	456.63 8.4	-7.26
	109.9	34	34	378.25 12.0	11.15
	175.8	35	35	390.77 17.3	8.21
	281.3	28	28	298.50 25.8	29.89*
	450.0	0	0	/ /	100*

*Inhibtion statistically significant (Dunett’s test; α=0.05)

Validity criteria fulfilled:

yes

Remarks:

In controls conditions for each species for the two studies: emergence rate was higher than 70%, mean survival of emerged seedling was higher than 90% and no phytotoxic effect was observed

Conclusions:

The first study (15-005-155277), performed on six species led to the following conclusions
Emergence was slowed for turnip, cress and wheat at 195.3 mg/kg soil dw and, for all species, between 312.5 mg/kg soil dry mass and 800.0 mg/kg soil dw.
The lowest NOEC for emergence at the end of exposure was determined for cress and wheat at 195.3 mg/kg soil dw

For seedling early growth , NOECs were determined for cress, radish and wheat : 195.3 mg/kg soil dw and garden bean : 500 mg/kg soil dw.
This last species was identified as the less sensitive. Though, no NOEC could be determined for turnip and barley as measured effects at the lowest tested concentration were statistically significant.

Therefore, a second study (15-009-155277) was performed on this two species.
Delays in emergence were reduced (no delay at 178.5 mg/kg soil dw, and, for turnip, 2 days at 450 mg/kg soil dw).

The results of this second study confirmed the sensitivity of barley to the test item with an absence of seedling emergence at 450 mg/kg soil dw and a NOEC determined at 175.8 mg/kg soil dw for seedling ealy growth.


For turnip the inhibition measured for the test concentration at 175.8 mg/kg soil dry mass (25.55 %) was statistically significant. However this effect was not confirmed at the two higher test concentrations, where inhibitions measured were not significant. It can be therefore considered that no statistically significant effect was observed at this highest tested concentration (450 mg/kg soil dry mass).

For this species, the lack of delay in appearance of cotyledon above the surface, as well as the lower duration to reach 60% of emergence may explain the difference of sensitivity between the results of the two studies.

Executive summary:

The effects of the test item “Reaction mass of 2-ethylhexyl mono D-glucopyranoside, 2-ethylhexyl di-D-glucopyranoside” incorporated into the soil, on the seedling emergence and early growth of terrestrial plants were assessed by performing two successive studies according to the procedure described in the OECD Guideline for testing chemicals n°208: "Terrestrial Plant Test: Seedling Emergence and Seedling Growth test"

In order to fullfil the ECHA recommendation regarding long term toxicity, six plant species (four dicotyledonous plants: turnip, garden bean, cress and radish; and two monocotyledonous plants: wheat and barley) were tested to determine the test item concentration range in which effects, on a reasonably broad selection of higher plants, are likely to occur.

During this first study, no NOEC for early growth can be determined for barley and turnip (significant effects at the lowest tested concentration). Therefore, a second study was performed with these two plant species, with a revised concentration range. The two studies were carried out in climatic chamber using a sandy loam soil as test substrate (LUFA 2.3). Soil moisture was maintained around 70% of the soil water holding capacity. Emergence and growth (dry biomass) were measured and NOECs and LOECs were determined for these two endpoints, for the six species (see table 9). Table 9 : NOECs and LOECs determined during the two studies (study 1 = 15 -005 -155277; study 2 = 15 -009 -155277)

		Turnip	Garden bean	Cress	Radish	Wheat	Barley
Emergence	NOEC (mg/kg soil dw)	Study 1: ≥ 800.0 Study 2: ≥ 450.0	≥ 800.0	195.3	500.0	195.3	Study 1: 312.5 Study 2 : 281.3
	LOEC (mg/kg soil dw)	/	/	312.5	800.0	312.5	Study 1 : 500.0 Study 2 : 450.0
Early growth	NOEC (mg/kg soil dw)	Study 1 :< 195.3 Study 2: ≥ 450	500.0	195.3	195.3	195.3	Study 1: < 195.3 Study 2 : 178.5
	LOEC (mg/kg soil dw)	Study 1 :195.3	800	312.5	312.5	312.5	Study 1: 195.3 Study 2 : 281.3

Barley was identified as the highest sensitive species and garden bean as the lowest sensitive species to the test item.

Description of key information

The first study (15-005-155277), performed on six species led to the following conclusions
Emergence was slowed for turnip, cress and wheat at 195.3 mg/kg soil dw and, for all species, between 312.5 mg/kg soil dry mass and 800.0 mg/kg soil dw.
The lowest NOEC for emergence at the end of exposure was determined for cress and wheat at 195.3 mg/kg soil dw

For seedling early growth , NOECs were determined for cress, radish and wheat : 195.3 mg/kg soil dw and garden bean : 500 mg/kg soil dw.
This last species was identified as the less sensitive. Though, no NOEC could be determined for turnip and barley as measured effects at the lowest tested concentration were statistically significant.

Therefore, a second study (15-009-155277) was performed on this two species.
Delays in emergence were reduced (no delay at 178.5 mg/kg soil dw, and, for turnip, 2 days at 450 mg/kg soil dw).

The results of this second study confirmed the sensitivity of barley to the test item with an absence of seedling emergence at 450 mg/kg soil dw and a NOEC determined at 175.8 mg/kg soil dw for seedling ealy growth.

For turnip the inhibition measured for the test concentration at 175.8 mg/kg soil dry mass (25.55 %) was statistically significant. However this effect was not confirmed at the two higher test concentrations, where inhibitions measured were not significant. It can be therefore considered that no statistically significant effect was observed at this highest tested concentration (450 mg/kg soil dry mass).

For this species, the lack of delay in appearance of cotyledon above the surface, as well as the lower duration to reach 60% of emergence may explain the difference of sensitivity between the results of the two studies.

Key value for chemical safety assessment

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

195.3 mg/kg soil dw