(Z)-N-octadec-9-enylhexadecan-1-amide

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:

experimental study

Adequacy of study:

key study

Study period:

08 Dec 2016 - 17 Feb 2017

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:

July 2006

Deviations:

yes

Remarks:

See detailes in section "Any other information on material and methods incl tables"

GLP compliance:

yes (incl. QA statement)

Remarks:

Hessisches Ministerium für Umwelt, Klimaschutz, Landwirtschaft und Verbraucherschutz, Wiesbaden, Germany

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

- Method of mixing into soil: Test item were weighed out for each treatment separately and ground with fine quartz sand and afterwards mixed into the test soil; concentration of sand added to the soil was 1% (i.e. 10 g/kg soil dw).
- Controls: Control soil received sand which has not been treated with the test item.
- Others: Application rate in detail is shown in Tables 3-5 in section "Any other information on material and methods incl tables".

Species:

other: Solanum lycopersicum

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Tomato
- Plant family: Solanaceae
- Lot number: 4317738
- Source of seed: Enza Zaden Deutschland GmbH & Co. KG, Dannstadt-Schauernheim, Germany
- Cultivar: Hellfrucht
- Seed storage: under cool and dry conditions in the dark
- Pretreatment of seeds: seeds had neither been dressed with fungicides nor imbibed with water

Species:

Pisum sativum

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Pea
- Plant family: Fabaceae
- Lot number: 117024NU
- Source of seed: Enza Zaden Deutschland GmbH & Co. KG, Dannstadt-Schauernheim, Germany
- Cultivar: Rondo
- Seed storage: under cool and dry conditions in the dark
- Pretreatment of seeds: seeds had neither been dressed with fungicides nor imbibed with water

Species:

Cucumis sativus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Cucumber
- Plant family: Cucurbitaceae
- Lot number: 4291508
- Source of seed: Enza Zaden Deutschland GmbH & Co. KG, Dannstadt-Schauernheim, Germany
- Cultivar: Delikatess
- Seed storage: under cool and dry conditions in the dark
- Pretreatment of seeds: seeds had neither been dressed with fungicides nor imbibed with water

Species:

Brassica napus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: rape
- Plant family: Brassicaceae
- Lot number: n.a.
- Source of seed: Feldsaaten Freudenberger, Krefeld, Germany
- Cultivar: Akela
- Seed storage: under cool and dry conditions in the dark
- Pretreatment of seeds: seeds had neither been dressed with fungicides nor imbibed with water

Species:

Allium cepa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Onion
- Plant family: Amaryllidaceae
- Lot number: 4333216
- Source of seed: Enza Zaden Deutschland GmbH & Co. KG, Dannstadt-Schauernheim, Germany;
- Cultivar: Stuttgarter Riesen
- Seed storage: under cool and dry conditions in the dark
- Pretreatment of seeds: seeds had neither been dressed with fungicides nor imbibed with water

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: oat
- Plant family: Poaceae
- Lot number: n.a.
- Source of seed: Nordsaat Saatzucht GmbH, Langenstein, Germany
- Cultivar: Canyon
- Seed storage: under cool and dry conditions in the dark
- Pretreatment of seeds: seeds had neither been dressed with fungicides nor imbibed with water

Test type:

seedling emergence and seedling growth test

Study type:

laboratory study

Substrate type:

natural soil

Limit test:

no

Total exposure duration:

21 d

Remarks:

Plants were left to grow under controlled conditions for a period of 14 to 21 days following seedling emergence of at least 50% in the control.

Test temperature:

mean air temperature ranging from 17.1 to 26.4 °C

pH:

5.9 ± 0.6 (soil, 0.01 M CaCl2)

Details on test conditions:

TEST SYSTEM
- Testing facility: ECT GmbH
- Test container (type, material, size): polypropylene pots (diameter 11 cm, height 8.5 cm), placed in a separate polystyrene beaker (Kastelplast GmbH, Mainz, Germany) serving as water reservoir
- Amount of soil: 468 ± 10 g soil fresh weight
- Method of seeding: seeds were randomly picked with a pair of tweezers and pressed into the soil at a uniform distance between seeds
- No. of seeds per container: 6 (for monocotyledonous) and 3 (for dicotyledonous)
- No. of replicates per treatment group: 4 (for monocotyledonous) and 7 (for dicotyledonous)
- No. of replicates per control: at least 4 (for monocotyledonous) and 7 (for dicotyledonous)

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Geographic location: LUFA Soil Type 2.3. (Batch F 2.3 4316) was collected from an uncultivated field at Offenbach, Rhineland-Palatinate, Germany on 24 Oct 2016 (information on soil properties was provided by the Landwirtschaftliche Untersuchungs-und Forschungsanstalt (LUFA) Speyer, Germany)
- Pesticide use history at the collection site: field had neither received any organic fertilisers nor plant protection substances during the last four years before sampling
Soil texture (if natural soil)
- % sand (0.05 – 2.0 mm): 59.6 ± 1.4
- % silt (0.002 – 0.05 mm): 33.6 ± 0.5
- % clay (< 0.002 mm): 6.8 ± 1.6
- Soil taxonomic classification: sandy loam
- Soil classification system: USDA
- Nitrogen (%): 0.08 ± 0.01
- Organic carbon (%): 0.67 ± 0.03
- Maximum water holding capacity (in % dry weigth): 35.6 ± 1.4
- CEC: 7.6 ± 0.8 meq/100 g
- Pretreatment of soil: soil was sieved (≤2 mm)
- Storage (condition, duration): Soil was stored at ECT GmbH at ambient temperature until usage.

NUTRIENT MEDIUM (if used)
- Description: nutrient solution (“Substral®”, 6 ml/L H2O) was added several times during the trial

GROWTH CONDITIONS
- Photoperiod: 16 h
- Light source: artificial lighting (SON-T-Agro high pressure metal halide lamps, Philips GmbH, Hamburg, Germany)
- Light intensity [μE m-2 s-1]: See Table 2 in section "Any other information on material and methods incl tables".
- Day/night temperatures: See Table 2 in section "Any other information on material and methods incl tables".
- Relative humidity (%): See Table 2 in section "Any other information on material and methods incl tables".
- Watering regime and schedules: See Table 1 in section "Any other information on material and methods incl tables".
- Volume applied: Deionised water was added to the reservoirs as necessary to maintain the soil sufficiently moist.
- Any pest control method/fertilization (if used): See Table 1 in section "Any other information on material and methods incl tables".

EFFECT PARAMETERS MEASURED: emergence rate, survival of seedlings, shoot fresh weight, and visual detrimental effects (chlorosis, necrosis, development abnormalities). Day 0 of the test was defined as the day by which at least 50% of the seedlings in the untreated control pots of a particular species had emerged. Visual detrimental effects were assessed on day 7, day 14, and at the end of the test, i.e. earliest on day 19 (day 15 for A. sativa), latest on day 21. Shoot fresh weight was evaluated only at the end of the test

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.16
Range finding study (non-GLP)
- Test concentrations: between 1.0 and 1000 mg/kg soil dry weight
- Results used to determine the conditions for the definitive study: Based on the results of the non-GLP range-finding test the main test was designed (results are summarized in table 1 in section "Any other information on results incl tables".

Nominal and measured concentrations:

Control, 10, 31.6, 100, 316 and 1000 mg test item /kg soil dw

Reference substance (positive control):

no

Species:

other: all six species

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: emergence, survival

Species:

other: all species except S.lycopersicum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot fresh weight

Species:

other: S.lycopersicum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot fresh weight

Species:

other: S.lycopersicum

Duration:

21 d

Dose descriptor:

EC25

Effect conc.:

745 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Shoot fresh weight

Species:

other: S.lycopersicum

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

78.5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shoot fresh weight

Species:

other: all six species

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: emergence, survival, shoot fresh weight

Remarks on result:

other: ECX assumed to be higher than 1000 mg/kg dw

Species:

other: all six species

Duration:

21 d

Dose descriptor:

EC25

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: emergence, survival and shoot fresh weight (except S.lycopersicum)

Remarks on result:

other: ECX assumed to be higher than 1000 mg/kg dw

Species:

other: all six species

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: emergence, survival and shoot fresh weight (except S.lycopersicum)

Remarks on result:

other: ECX assumed to be higher than 1000 mg/kg dw

Details on results:

SEEDLING EMERGENCE
- Percent seedling emergence (untreated control pot):
75.0 % (A.cepa)
91.7 % (A. sativa)
95.2 % (B. napus)
100 % (C.sativus)
81.0 % (P. sativum)
85.7 % (S.lycopersicum)

- Percent survival (untreated control pot):
100 % (A.cepa)
100 % (A. sativa)
90.0 % (B. napus)
100 % (C.sativus)
94.1 % (P. sativum)
100 % (S.lycopersicum)

-Visual appearance: Plants growing in treated soil did not differ in their visual appearance from plants growing in non-treated control soil and did not exhibit any visible test item related damages.

- Others: See section" Any other information on results incl tables for further biological results"

Results of non-GLP range-finding Test

Table 1: Shoot fresh weight of seedlings grown in test item treated soil as determined on day 14 of the range-finding test; data given as percentage of the control.

Species	Test concentration [mg/kg soil]
	1	10	100	1000
	Shoot fresh weight [% of control]
A. cepa	87.6	168.5	146.1	98.9
A. sativa	100	101.0	85.0	108.3
B. napus	113.1	76.9	99.5	97.9
C. sativus	114.9	119.7	125.4	107.4
P. sativum	59.5	80.1	71.1	56.9
S. lycopersicum	82.7	85.5	79.9	97.1

 

Results of main test:

The test with A. sativa was repeated, since the validity criteria had not been met in first run. Only the results of the repeated test with A. sativa are reported. The tests with the species A. cepa, P. sativum and S. lycopersicum (only results of 2nd run are shown here) were both valid considering the validity criteria given by the test guideline. Consequently the results of both test runs were evaluated separately and are reported.

 

Seedling Emergence and Survival

Emergence in the control was at least 75%. Survival of seedlings in the controls was at least 90%. Hence, the requirements defined by the test guideline regarding emergence and survival of seedlings were fulfilled. Neither emergence nor survival of the seedlings was statistically significantly affected in any of the species at test item concentrations up to and including 1000 mg/kg soil dry weight which was the highest tested concentration.

Seedling Shoot Fresh Weight

Shoot fresh weight of plants growing in test item treated soil was not statistically significantly different from shoot weight of the plants growing in untreated control soil for any of the six species at concentrations up to and including 1000 mg/kg soil dry weight. In the repeated test, however, shoot fresh weight of S. lycopersicum was statistically significantly reduced by 20% and 27% at test item concentrations of 316 and 1000 mg/kg soil dw, respectively.

Table 1: Seedling emergence (emergence after day 7 not considered)

Treatment code	C	T1	T2	T3	T4	T5
Test item [mg/kg soil dw]	0.0	10	31.6	100	316	1000
	Number of seeds planted
A. cepa (2nd run)	24	24	24	24	24	24
A. sativa	24	24	24	24	24	24
B. napus	21	21	21	21	21	21
C. sativus	21	21	21	21	21	21
P. sativum (2nd run)	21	21	21	21	21	21
S. lycopersicum (2nd run)	21	21	21	21	21	21
	Number of emerged seeds per treatment on day 7
A. cepa (2nd run)	21	20	19	17	21	18
A. sativa	22	22	23	22	23	23
B. napus	20	21	20	19	19	20
C. sativus	21	20	20	20	20	20
P. sativum (2nd run)	20	19	19	18	20	17
S. lycopersicum (2nd run)	19	21	20	21	20	21
	Relative number of emerged seeds [% of seeds sown]
A. cepa (2nd run)	87.5	83.3	79.2	70.8	87.5	75.0
A. sativa	91.7	91.7	95.8	91.7	95.8	95.8
B. napus	95.2	100	95.2	90.5	90.5	95.2
C. sativus	100	95.2	95.2	95.2	95.2	95.2
P. sativum (2nd run)	95.2	90.5	90.5	85.7	95.2	81.0
S. lycopersicum (2nd run)	90.5	100	95.2	100	95.2	100
	Mean % emergence as % of mean emergence of the control
A. cepa (2nd run)	100	95.2	90.5	80.9	100	85.7
A. sativa	100	100	104	100	104	104
B. napus	100	105	100	95.1	95.1	100
C. sativus	100	95.2	95.2	95.2	95.2	95
P. sativum (2nd run)	100	95.1	95.1	90.0	100	85.1
S. lycopersicum (2nd run)	100	111	105	111	105	111

*Accidentally no seeds sowed in one of the pots of this treatment.

Table 2: Seedling survival (emergence after day 7 not considered)

Treatment code	C	T1	T2	T3	T4	T5
Test item [mg/kg soil dw]	0.0	10	31.6	100	316	1000
	Number of emerged seeds per treatment on day 7
A. cepa (2^ndrun)	21	20	20	17	21	18
A. sativa	22	22	23	22	23	23
B. napus	20	21	20	19	19	20
C. sativus	21	20	20	20	20	20
P. sativum (2^ndrun)	20	19	19	18	20	17
S. lycopersicum (2^ndrun)	19	21	20	21	20	21
	Number of live seedlings at test end
A. cepa (2^ndrun)	21	19	18	17	20	18
A. sativa	22	22	23	22	23	23
B. napus	18	20	20	18	18	20
C. sativus	21	20	20	19	20	20
P. sativum (2^ndrun)	20	19	19	18	20	17
S. lycopersicum (2^ndrun)	19	21	20	21	20	20
	Relative number of live seedlings at test end [% of emerged]
A. cepa (2^ndrun)	100	95.0	90.0	100	95.2	100
A. sativa	100	100	100	100	100	100
B. napus	90.0	95.2	100	94.7	94.7	100
C. sativus	100	100	100	95.0	100	100
P. sativum (2^ndrun)	100	100	100	100	100	100
S. lycopersicum (2^ndrun)	100	100	100	100	100	95.2
	Mean % survival as % of mean survival of the control
A. cepa (2^ndrun)	100	95.0	90.0	100	95.2	100
A. sativa	100	100	100	100	100	100
B. napus	100	106	111	105	105	111
C. sativus	100	100	100	95	100	100
P. sativum (2^ndrun)	100	100	100	100	100	100
S. lycopersicum (2^ndrun)	100	100	100	100	100	95.2

Validity criteria fulfilled:

yes

Description of key information

EC10 (21 d): 78.5 mg/kg soil (Solanum lycopersicum, shoot fresh weight, OECD 208, nominal)

Key value for chemical safety assessment

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

78.5 mg/kg soil dw

Additional information

One experimental study is available investigating the potential effects of the test item (CAS 16260-09-6) on seedling emergence and growth (ECT, 2017) of plants. The studies were performed according to OECD guideline 208 under GLP conditions. For this study six species of non-target terrestrial plants (2 monocots and 4 dicots) were planted in a natural sandy loam soil (standard soil LUFA Sp 2.3) immediately after test item application. Five test item concentrations were tested with each species: 10, 31.6, 100, 316 and 1000 mg test item /kg soil dw. Plants were left to grow under controlled conditions for a period of 14 to 21 days following seedling emergence of at least 50% in the control. Test item concentrations were applied within artificial soil. The control soil received sand which had not been treated with the test item. Soils were supplied with water and a nutrient solution as needed by bottom watering. The test was performed in growth chambers equipped with artificial lighting (201 to 352 μE m-2 s-1, for 16 hours per day) and air conditioning (mean air temperature ranging from 17.1 to 26.4 °C, relative humidity ranging from 17.0% to 58.1%). The pots were randomly placed at the beginning of the test and were re-arranged at minimum weekly intervals. On day 7 and day 14 (or day 17 for A. cepa) after 50% emergence of control, seedlings were evaluated visually. At the end of the test, seedlings were counted, evaluated visually, and harvested to determine shoot fresh weight. At concentrations up to and including 1000 mg/kg soil dry weight the test item had no statistically significant adverse effect on either seedling emergence, seedling survival or shoot fresh weight of any of the six test species. Shoot fresh weight of the test species Solanum lycopersicum in the second test run was reduced at concentrations of ≥ 100 mg/kg soil dry weight (P<0.05). Therefore the lowest LOEC (lowest observed effect concentration) and NOEC (no observed effect concentration) were determined to be 316 mg/kg soil dw and 100 mg/kg soil dw, respectively. Due to the lack of either adverse effects or a concentration response relationship effective concentrations could not be calculated and are assumed to be higher than 1000 mg/kg dw except for shoot fresh weight of S. lycopersicum (second test run). For S. lycopersicum the EC10 and EC25 were calculated to be 78.5 mg/kg soil dry weight and 745 mg/kg soil dry weight, respectively, while the EC50 was >1000 mg/kg soil dry weight under the conditions of this test.