A mixture of cis- and trans-cyclohexadec-8-en-1-one

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:

2021-10-20 to 2021-12-15

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:

During cultivation, the test containers were bottom watered with tap water including fertilizer instead of demineralised water to guarantee good plant growth. No randomization of the test containers was carried out during the test.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: oats
- 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
- 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 and seedling growth test

Study type:

laboratory study

Substrate type:

natural soil

Limit test:

no

Total exposure duration:

56 d

Test temperature:

12.1-28.9 °C

Moisture:

27.5-80.6%

Details on test conditions:

TEST SYSTEM
- Testing facility: Noack Laboratorien
- Test container (type, material, size): Plastic container (Ø10 cm) including glass fibre wicks to ensure homogeneous watering were used. Each test container was placed on an individual water reservoir.
- Amount of soil: 400 g treated soil
- No. of seeds per container: 10
- No. of plants (retained after thinning): 8
- No. of replicates per treatment group: 6
- No. of replicates per control: 6


SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Geographic location: Landwirtschaftliche Untersuchungs- und Forschungsanstalt Speyer (LUFA), Obere Langgasse 40, 67346 Speyer, Germany
- Sampling depth (cm): 20
- Soil texture: loamy sand
- % sand: 84.9%
- % silt: 9.7%
- % clay: 5.4%
- Soil classification system: DIN classification
- Composition: a 2:1 mixture of natural soil LUFA 2.2 (batch number: Sp2.20621) and quartz sand was used.
- Organic carbon (%): 1.05%
- CEC: 8.5 +/- 2 .0 meq/100 g
- Storage (condition, duration): greenhouse conditions

GROWTH CONDITIONS
- Light source: Special LED modules for plant growing
- Wavelength 400-700 nm
- Watering regime: Bottom watering of the test container with fertilizer as needed.
- Fertilization: HAKAPHOS® SOFT SPEZIAL 16+8+22(+3) For watering a 0.5 ‰ solution was used. Origin: Grünes Landhaus, St. Godehard-Str. 23, 31139 Hildesheim, Germany

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Range finding study
- Test concentrations: 1000 - 500 - 100 - 10 mg/kg DW
- Results used to determine the conditions for the definitive study: yes

Nominal and measured concentrations:

Nominal concentrations: 1000 - 500 - 250 - 125 - 62.5 mg/kg DW (factor 2)

Reference substance (positive control):

yes

Remarks:

Boric acid

Key result

Species:

Avena sativa

Duration:

56 d

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

Including shoot height, fresh weight and dry weight

Key result

Species:

Avena sativa

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

62.5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

Blossom dry weight

Species:

Avena sativa

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

250 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

Blossom fresh weight

Species:

Avena sativa

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

Number of blossoms

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:

test mat.

Basis for effect:

growth

Remarks:

including shoot height, fresh weight and dry weight

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:

test mat.

Basis for effect:

growth

Remarks:

Including the number of busks, husk fresh and dry weight

Details on results:

See below

Results with reference substance (positive control):

- Results with reference substance valid?
- Relevant effect levels:
- Other:

Table. 1: Seeding Emergence [%] after 7 days:

Test concentration [mg/kg DW]	Seedling emergence [%]
	Oats	Turnip
Control	95	90
62.5	90	97
125	95	93
250	95	87
500	98	93
1000	98	88

Table. 2: Oats: Inhibition [%] of Shoots (Acute Effects)

Test concentration [mg/kg DW]	Shoot height [cm]	Inhibition [%]	Fresh weight of shoots [mg]	Inhibition [%]	Dry weight of shoots [mg]	Inhibition [%]
Control	84.1	-	23358	-	5853	-
62.5	83.1	1	22701	3	5566	5
125	81.1	4	23510	-1	5014	14
250	80.7	4	20712	11	5020	14
500	77.8	7	21846	6	5390	8
1000	76.8	9	18188	22	4493	23

Table. 3: Oats: Inhibition [%] of Blossoms (Chronic Effects)

Test concentration [mg/kg DW]	Number of blossoms^1)	Inhibition [%]	Fresh weight of blossoms[mg]	Inhibition [%]	Dry weight of blossoms[mg]	Inhibition [%]
Control	249	-	58		14.77	-
62.5	257	-3	54	7	12.12	18
125	243	2	50	14	10.18	31
250	244	2	50	14	11.23	24
500	237	5	44	24	9.58	35
1000	231	7	46	21	10.50	29

Table. 4: Turnip: Inhibition [%] of Shoots (Acute Effects)

Test concentration [mg/kg DW]	Shoot height [cm]	Inhibition [%]	Fresh weight of shoots^1) [mg]	Inhibition [%]	Dry weight of shoots [mg]	Inhibition [%]
Control	37.2	-	4645	-	828	-
62.5	39.4	-6	4775	-3	800	3
125	32.7	12	4805	-3	838	-1
250	33.9	9	5617	-21	939	-13
500	31.3	16	4926	-6	786	5
1000	26.5	29	4729	-2	689	17

TAble. 5: Turnip: Inhibition [%] of Husks (Chronic Effects)

Test concentration [mg/kg DW]	Number of husks	Inhibition [%]	Fresh weight of husks [mg]	Inhibition [%]	Dry weight of husks [mg]	Inhibition [%]
Control	171	-	223	-	38.53	-
62.5	163	5	240	-8	41.52	-8
125	156	9	238	-7	39.63	-3
250	154	10	237	-6	38.03	1
500	149	13	211	5	34.15	11
1000	106	38	206	8	27.92	28

negative values = promoted growth  1) Equal variance test failed
bold = statistically significant inhibition

 

Validity criteria fulfilled:

yes

Remarks:

- a 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 - the number of dead control plants was ≤ 1 plant / replicate

Conclusions:

The acute effects of the test item (EC50) to oats and turnip were above 1000 mg/kg DW on the basis of the effect for height, fresh weight and dry weight of shoot. The chronic effect of the test item to oats (NOEC) was determined to be 62.5 mg/kg DW on the basis of the effect for the dry weight of blossom and the chronic effect of the test item to turnip (NOEC) was determined to be 1000 mg/kg DW on the basis of the effect for the number, fresh weight and dry weight of husks.

Executive summary:

The study on the acute and chronic toxicity of the test item to two terrestrial plant species were determined according to DIN ISO 22030:2005 and GLP. The test plants were one monocotyledon (oats) and one dicotyledon (turnip). According to the results of a range-finder, the test was conducted at the test item concentrations 1000 - 500 - 250 - 125 - 62.5 mg/kg DW (factor 2). 6 replicates per test concentration and control were tested in a randomised block design and 10 seeds per test container were sown. A 2:1 mixture of natural soil LUFA 2.2 and quartz sand was used. The test item was incorporated into the soil once before the seeds were sown. The test containers were bottom watered with nutrient solution via glass fibre wicks. The acute effects of the test item (EC50) to oats and turnip were above 1000 mg/kg DW on the basis of the effect for height, fresh weight and dry weight of shoot. The chronic effect of the test item to oats (NOEC) was determined to be 62.5 mg/kg DW on the basis of the effect for the dry weight of blossom and the chronic effect of the test item to turnip (NOEC) was determined to be 1000 mg/kg DW on the basis of the effect for the number, fresh weight and dry weight of husks.

Description of key information

A study on the acute and chronic toxicity of the test item to two terrestrial plant species is available. The test was determined according to DIN ISO 22030:2005 and GLP. The test plants were one monocotyledon (oats) and one dicotyledon (turnip). According to the results of a range-finder, the test was conducted at the test item concentrations 1000 - 500 - 250 - 125 - 62.5 mg/kg DW (factor 2). 6 replicates per test concentration and control were tested in a randomised block design and 10 seeds per test container were sown. A 2:1 mixture of natural soil LUFA 2.2 and quartz sand was used. The test item was incorporated into the soil once before the seeds were sown. The test containers were bottom watered with nutrient solution via glass fibre wicks. The acute effects of the test item (EC50) to oats and turnip were above 1000 mg/kg DW on the basis of the effect for height, fresh weight and dry weight of shoot. The chronic effect of the test item to oats (NOEC) was determined to be 62.5 mg/kg DW on the basis of the effect for the dry weight of blossom and the chronic effect of the test item to turnip (NOEC) was determined to be 1000 mg/kg DW on the basis of the effect for the number, fresh weight and dry weight of husks.

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:

62.5 mg/kg soil dw