Hydrocarbons, C18-C24, iso-alkanes <2% aromatics

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:

19 November 2015 and 10 December 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

See test material information

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

A definitive test was undertaken using the concentrations of 0 (control), 95, 172, 309, 556 and 1000 mg product/kg dry substrate.
The organic carbon content of test substrate was determined to be 2.5%, which was above that specified for use in the test. As a result, the test substrate was cut with industrial quartz sand prior to use, to achieve an organic carbon content of <1.5%.
- Method of mixing into soil (if used): Sand stocks for each treatment group were prepared by adding the appropriate amount of test substance into either a 500 mL or 1.0 L glass jar containing pre-weighed sand. The glass jars were then sealed, placed in a cement mixer, and rolled for a total of 75 minutes to homogenise the mixtures. Following homogenisation in the cement mixture, and due to the capacity of the mixer used for test substrate mixing, the treated sand was divided into three even sub-samples per rate.
The test substrate was prepared in bulk, consisting of a total of 20.4 kg dry weight per test rate, prepared in three sub-batches per test rate. Per sub-batch, approximately half of the test substrate was placed in a stainless steel Hobart mechanical mixer, and the test substance, incorporated into sand, was evenly distributed across the surface of the test substrate within the mixer. The remaining substrate was then placed on top of this, without disturbing the sand layer, prior to mixing. Each test rate was thoroughly mixed for 5 minutes, followed by a thorough hand-turn. At this point, approximately 100 mL of mains water was added to the mixture, followed by an additional 5 minute mechanical mix. This was deemed sufficient to thoroughly incorporate the test substance into the test substrate.

Test Vessels
Test vessels were 11 × 11 × 12 cm injection-moulded square pots, with both base and side drainage holes. They were labelled with appropriate outdoor weather-proof plant labels, identifying the study number, test rate, phase of study, and unique vessel number.
Test vessels were placed in large plastic garden trays, with each tray holding one whole test rate (24 pots). Test rates were maintained separately to avoid contamination between concentrations.
Following test substrate preparation, each prepared test rate was evenly allocated to the respective test vessels, equivalent to approximately 850 g dry weight per replicate.

Sowing
The seeds were sown at an appropriate depth for each species, and were spaced according to the number of seeds per pot. Sowing depth was achieved by the use of the bulb end of a disposable Pasteur pipette, delineated to allow for consistent planting depths.
The seeds were sown on the same day as treatment application, following test substrate preparation.
Seedlings were maintained in a Weiss Gallenkamp Fitotron Incubator for the duration of the test.

Plants were watered, as necessary, using mains water via a suitable hand sprayer.

Initially the pots were surface-watered and bottom-watered in trays, with effort being made not to disturb or flood the substrate. Once the seedlings were established, the pots were bottom-watered in the trays, as required, to prevent the drying of the substrate. No supplemental nutrients or feed were required during the test.

- Controls: Test substrate with no test substance

Species:

Brassica rapa

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Turnip
- Plant family:
- Variety: Golden Ball/White Globe
- Source of seed: Chase Garden
- Prior seed treatment/sterilization:
- Historical germination of seed (germination of seed lot tested):
- Seed storage:

Species:

other: Solanum lycopersicum

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Tomato
- Plant family:
- Variety: Moneymaker
- Source of seed: Chase Garden
- Prior seed treatment/sterilization:
- Historical germination of seed (germination of seed lot tested):
- Seed storage:

Species:

Phaseolus vulgaris

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Dwarf bean
- Plant family:
- Variety: The Prince
- Source of seed: Chase Garden
- Prior seed treatment/sterilization:
- Historical germination of seed (germination of seed lot tested):
- Seed storage:

Species:

other: Fagopyrum esculentum

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Buckwheat
- Plant family:
- Variety: Not available
- Source of seed: Chase Garden
- Prior seed treatment/sterilization:
- Historical germination of seed (germination of seed lot tested):
- Seed storage:

Species:

Triticum aestivum

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Wheat
- Plant family:
- Variety: Not available
- Source of seed: Infinity Foods
- Prior seed treatment/sterilization:
- Historical germination of seed (germination of seed lot tested):
- Seed storage:

Species:

Lolium perenne

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Ryegrass
- Plant family:
- Variety: Not available
- Source of seed: Chase Garden
- Prior seed treatment/sterilization:
- Historical germination of seed (germination of seed lot tested):
- Seed storage:

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:

21.3 - 27.3 °C

pH:

6.15

Moisture:

The wet:dry ratio was determined to be 1.11

Details on test conditions:

TEST SYSTEM
- Testing facility: Smithers Viscient greenhouse
- Test container (type, material, size): 11 × 11 × 12 cm injection-moulded square pots, with both base and side drainage holes. Test vessels were placed in large plastic garden trays, with each tray holding one whole test rate (24 pots).
- Amount of soil: 850 g dry weight per replicate
- Method of seeding: The seeds were sown at an appropriate depth for each species, and were spaced according to the number of seeds per pot.
- No. of seeds per container: 5
- No. of plants (retained after thinning): not reported
- No. of replicates per treatment group: 4
- No. of replicates per control: 4

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Geographic location: Boughton Loam & Turf Management
- Pesticide use history at the collection site: Not reported
- Collection procedures: not reported
- Sampling depth (cm): not reported
- Soil texture (if natural soil) Sandy loam
Fine gravel: 5000-2000 = 1%
- % sand: Very coarse sand 5000 - 2000 = 2%
Coarse sand 1000 - 500 = 3%
Medium sand 500 - 250 = 13%
Fine sand 250 - 125 = 16%
Very fine sand 125 - 60 = 7%
- % silt: Coarse silt 60 - 20 = 18%
Silt 60 - 21 = 17%
- % clay: Clay <2 = 23%
- Soil taxonomic classification: Not reported
- Soil classification system: Not reported
- Composition (if artificial substrate): n/a
- Organic carbon (%): Organic Carbon Content was determined to be 2.5 %; Organic Matter was calculated to be 4.3%.
- Maximum water holding capacity (in % dry weight): not reported
- CEC: not reported
- Pretreatment of soil: Upon receipt, the substrate was subjected to pH, moisture content analysis and organic matter / organic carbon content determination.
The organic carbon content of test substrate was determined to be 2.5%, which was above that specified for use in the test. As a result, the test substrate was cut with industrial quartz sand prior to use, to achieve an organic carbon content of <1.5%.
- Storage (condition, duration): not reported

NUTRIENT MEDIUM (if used)
- Description: none reported

GROWTH CONDITIONS
- Photoperiod: 16:8 hour light:dark cycle
- Light source: fluorescent lighting
- Light intensity and quality: 350 ± 50 μmol/m2/sec at the substrate surface
- Day/night temperatures: 21.3 - 27.3 °C
- Relative humidity (%): 39*-94% *On the final day of the study humidity was observed to be below the target range of 70% ± 25%. At this point only one species (tomato) remained to be harvested. This is not expected to have had any impact on the outcome of the study.
- Wind velocity: n/a - incubator
- Air exchange rate: not reported
- Watering regime and schedules: Plants were watered, as necessary, using mains water via a suitable hand sprayer.
Initially the pots were surface-watered and bottom-watered in trays, with effort being made not to disturb or flood the substrate. Once the seedlings were established, the pots were bottom-watered in the trays, as required, to prevent the drying of the substrate. No supplemental nutrients or feed were required during the test.
- Water source/type: mains water
- Volume applied: as necessary
- Interval of applications: as necessary
- Method of application: hand sprayer
- Any pest control method/fertilization (if used): no

ACCLIMATION PERIOD: not reported

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Emergence
The number of emerged seeds was recorded per replicate. Emergence was assessed daily until the date of harvest.
Visual effects Observations
Qualitative assessment was made of visual phytotoxic effects. A scoring system was conducted based on percent effect per observation category. Percentage scores were assigned as a measure of the overall visual effects for all seedlings in one vessel, (e.g. the stand of seedlings in each replicate vessel), compared to the controls. For visual effects the vessel was considered to be the replicate, and not the individual plants within each vessel.
Visual effects assessments were conducted at least weekly for a period of between 14 to 21 days after 50% emergence was achieved in the controls, and on the day of harvest.
Growth
The seedlings were harvested 15 days after each species had reached 50% control emergence. Seedlings were cut at the substrate surface, and weighed on a calibrated balance, to determine seedling wet weight (biomass).
- Phytotoxicity rating system (if used): Qualitative assessment was made of visual phytotoxic effects. A scoring system was conducted based on percent effect per observation category. Percentage scores were assigned as a measure of the overall visual effects for all seedlings in one vessel, (e.g. the stand of seedlings in each replicate vessel), compared to the controls. For visual effects the vessel was considered to be the replicate, and not the individual plants within each vessel.
Visual effects assessments were conducted at least weekly for a period of between 14 to 21 days after 50% emergence was achieved in the controls, and on the day of harvest.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: Approximately 1.8
- Justification for using less concentrations than requested by guideline: n/a
- Range finding study
Spray Feasibility Trial
At the request of the Sponsor, a feasibility trial was conducted at an in-field application rate of 400 L/ha with the test substance to ascertain its suitability to a spray application.
Prior to spraying, a 1000 g product/ha solution was prepared by adding 25.00 mg of test substance to a suitable vessel with 25.21 mg of Span®40 and 25.96 mg of Tween®40. Following this, the solution was made up to a volume of 100 mL using the reverse osmosis (RO) water/Span®40/Tween®40 mixture and sonicated at approximately 35°C for 10 minutes, and for a further 30 minutes at approximately 50°C. This produced an opaque milky solution with no visible undissolved material. The techniques used to produce the test substance solution were based on previous solubility trials performed on behalf of the Sponsor, and provided by the Sponsor to the Test Facility to be used as supporting data.
Surface spray application was performed using a Laboratory Potter Spray Tower, calibrated at a volume equivalent to 400 L/ha water. The Laboratory Potter Spray Tower was calibrated with RO water immediately prior to application, following procedures described in local SOP’s. A target rate of 400 L/ha is equivalent to a deposit of 4 mg/cm2; acceptable limits of ± 10%, e.g. 3.6 to 4.4 mg/cm2 were applied. Eight consecutive calibration runs within the given limits were achieved with RO water prior to spraying.
The spraying of the 1000 g product/ha solution was sequentially performed a total of 10 times and observations of the resulting spray procedure were detailed in the raw data.
Results:
Ten sequential sprays were performed using the Laboratory Potter Spray Tower. It was observed that each spray was successful, with no signs of an abnormal spray. There was no indication of the spray nozzle being obstructed/blocked and the coverage of the spray was observed to be even across the spray platform. The preparation of the test substance using Tween® 40/Span® 40 and RO water was therefore determined to be suitable for spray application.

Nominal and measured concentrations:

0 (control), 95, 172, 309, 556 and 1000 mg product/kg dry substrate

Reference substance (positive control):

not specified

Species:

Triticum aestivum

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, biomass and phytotoxicity

Species:

Triticum aestivum

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, biomass and phytotoxicity

Species:

Brassica rapa

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, biomass and phytotoxicity

Species:

Brassica rapa

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, biomass and phytotoxicity

Species:

other: Fagopyrum esculentum

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, biomass and phytotoxicity

Species:

other: Fagopyrum esculentum

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, biomass and phytotoxicity

Species:

other: Phaseolus vulgaris

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, biomass and phytotoxicity

Species:

other: Phaseolus vulgaris

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, biomass and phytotoxicity

Species:

Lolium perenne

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, biomass and phytotoxicity

Species:

Lolium perenne

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, biomass and phytotoxicity

Species:

other: Solanum 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: emergence, biomass and phytotoxicity

Species:

other: Solanum lycopersicum

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, biomass and phytotoxicity

Details on results:

Emergence was assessed daily until the date of harvest. Emergence data is presented in Table 1, in "any other information on results including tables".
An additional ryegrass seedling was noted during the assessments of a single control replicate. As all ryegrass within the control emerged, the overall emergence was recorded as 100%.
With the exception of ryegrass, all emergence data was analysed using a Steel Many-One Rank Sum or Dunnetts Multiple Comparison tests. All the analysed test species were determined to show no significant differences in the number of emerged seedlings, when compared to the controls, in any of the test rates.
Therefore, the NOEC and LOEC values for emergence were determined to be 1000 and >1000 mg product/kg, respectively, for buckwheat, ryegrass, dwarf bean, tomato, turnip and wheat.
Ryegrass showed an inverted dose response; an effect was noted in the 309 mg product/kg test rate (p = <0.05) of 75% emergence at the time of harvest, when compared to 100% emergence in the control. However, the higher test rates showed no statistically significant difference in emergence when compared to the control, and therefore the NOEC and LOEC values for ryegrass emergence were empirically determined to be 1000 and >1000 mg product/kg, respectively.
Furthermore, all emergence data was analysed using Linear Interpolation (ICPIN) or Two-Point Interpolation, the EC50 values were determined to be >1000 mg product/kg, for all test species.

Biomass (Seedling Wet Weight)
Seedling wet weight was determined, per replicate, immediately post-harvest, and is presented in Table 2, in "any other information on results including tables".
All seedling wet weight data was analysed using a Dunnetts Multiple Comparison test. Buckwheat, ryegrass, dwarf bean, tomato, turnip and wheat showed no significant differences in seedling wet weight, when compared to the controls, in any of the test rates.
In all species, with the exception of dwarf bean and tomato, a statistically significant positive effect on the growth of the seedlings under the influence of the test substance was observed.
Therefore, the NOEC and LOEC values for seedling wet weight for all test species were determined to be 1000 and >1000 mg product/kg, respectively.
Furthermore, all biomass (seedling wet weight) data was analysed using Linear Interpolation (ICPIN) or Two-Point Interpolation, the EC50 values were determined to be >1000 mg product/kg, for all test species.

Phytotoxicity
As only minor phytotoxic effects were observed, or observed in the control but not with the corresponding test rates (e.g. buckwheat), the NOEC, LOEC and EC50 values have been empirically determined for all species at all of the observation intervals; including the date of harvest to be 1000, >1000 and >1000 mg product/kg, respectively.
The results observed with buckwheat are directly attributable to the growing conditions, whereby on the day prior to or on the day of harvest, minor phytotoxic effects which included stem wilting and leaf wilting were observed. As the same observations were seen in both the control and test rates; these effects are not considered to be as a consequence of the test substance.

Spray Feasibility Trial
Ten sequential sprays were performed using the Laboratory Potter Spray Tower. It was observed that each spray was successful, with no signs of an abnormal spray. There was no indication of the spray nozzle being obstructed/blocked and the coverage of the spray was observed to be even across the spray platform. The preparation of the test substance using Tween® 40/Span® 40 and RO water was therefore determined to be suitable for spray application.

Results with reference substance (positive control):

n/a

Reported statistics and error estimates:

Statistical analysis of the data was undertaken using CETIS version 1.8.6.8, based on the nominal test rates. The following methods were used;
- Steel Many-One Rank Sum Test or Dunnett Multiple Comparison Test was used to determine the NOEC and LOEC values for emergence and seedling wet weight (biomass) for all test species (except Ryegrass).
- A Linear Interpolation Test (ICPIN) or Two-Point Interpolation was used to determine the EC50 for emergence and seedling wet weight (biomass) for all test species.
The NOEC, LOEC and EC50 values for phytotoxic effects were determined empirically.

Table 1: Seedling Emergence Summary

Species	Test Concentration (mg product/kg dry substrate)	Mean % emergence
Buckwheat	0 (Control)	100
	95	90
	172	95
	309	100
	556	95
	1000	100
Ryegrass	0 (Control)	100
	95	90
	172	100
	309	75
	556	85
	1000	85
Dwarf bean	0 (Control)	100
	95	100
	172	100
	309	100
	556	100
	1000	95
Tomato	0 (Control)	75
	95	80
	172	70
	309	65
	556	75
	1000	60
Turnip	0 (Control)	100
	95	100
	172	95
	309	90
	556	80
	1000	85
Wheat	0 (Control)	80
	95	100
	172	100
	309	85
	556	85
	1000	85

Table 2: Seedling Wet Weight Summary

Species	Test Concentration (mg product/kg dry substrate)	Mean Wet Weight (mg)	% Reduction compared to the control
Buckwheat	0 (Control)	257	N/A
	95	358	-39
	172	422	-64
	309	329	-28
	556	512	-99
	1000	424	-65
Ryegrass	0 (Control)	110	N/A
	95	123	-12
	172	115	-5
	309	73	34
	556	114	-4
	1000	124	-13
Dwarf bean	0 (Control)	3588	N/A
	95	3607	-1
	172	3201	11
	309	3131	13
	556	2686	25
	1000	3683	-3
Tomato	0 (Control)	203	N/A
	95	261	-28
	172	135	34
	309	237	-17
	556	123	39
	1000	133	35
Turnip	0 (Control)	104	N/A
	95	123	-18
	172	118	-13
	309	155	-49
	556	127	-22
	1000	99	5
Wheat	0 (Control)	193	N/A
	95	210	-9
	172	215	-12
	309	163	15
	556	245	-27
	1000	186	4

Validity criteria fulfilled:

yes

Conclusions:

The effect of the test item on seedling emergence and early growth of higher plants has been investigated. The results are as follows:
Test Rate mg product/kg dry substrate
Species Endpoint NOEC LOEC EC50
Wheat Emergence 1000 >1000 >1000
Biomass 1000 >1000 >1000
Phytotoxicity 1000 >1000 >1000
Turnip Emergence 1000 >1000 >1000
Biomass 1000 >1000 >1000
Phytotoxicity 1000 >1000 >1000
Buckwheat Emergence 1000 >1000 >1000
Biomass 1000 >1000 >1000
Phytotoxicity 1000 >1000 >1000
Dwarf Bean Emergence 1000 >1000 >1000
Biomass 1000 >1000 >1000
Phytotoxicity 1000 >1000 >1000
Ryegrass Emergence 1000 >1000 >1000
Biomass 1000 >1000 >1000
Phytotoxicity 1000 >1000 >1000
Tomato Emergence 1000 >1000 >1000
Biomass 1000 >1000 >1000
Phytotoxicity 1000 >1000 >1000

Executive summary:

Introduction

A study was performed to determine the potential effects of the test substance on seedling emergence and early growth of higher plants.

Six seedling species, from a range of selected higher plants (monocotyledonae and dicotyledonae species), were exposed to the test substance incorporated into the test substrate. This study was conducted according to the procedures outlined in the study protocol. The protocol was based on the procedures specified in OECD Guideline 208 (OECD, 2006) (Terrestrial Plants Test: Seedling Emergence and Seedling Growth Test).

 

Methods…….

A definitive test was conducted at the following test concentrations: 0 (control), 95, 172, 309, 556 and 1000 mg product/kg dry substrate, for a period of 21 days after seedling emergence.

As the test substance was not readily soluble in water, it was applied to the test substrate using a sand carrier.

Four replicate vessels were prepared for each test concentration and four replicate vessels were prepared for the control(s), each replicate containing five seeds per test vessel.

Assessment of effects on percent emergence, visual phytotoxicity and growth were conducted in comparison with the control treatment.

 

Results…….

The no observable effect concentration (NOEC), the lowest observed effect concentration (LOEC), and the EC₅₀ values were determined for seedling emergence, seedling wet weight (expressed as biomass), and phytotoxicity.

Based on nominal concentrations of the test substance, the results are as follows:

		Test Rate mg product/kg dry substrate
Species	Endpoint	NOEC	LOEC	EC50
Wheat	Emergence	1000	>1000	>1000
	Biomass	1000	>1000	>1000
	Phytotoxicity	1000	>1000	>1000
Turnip	Emergence	1000	>1000	>1000
	Biomass	1000	>1000	>1000
	Phytotoxicity	1000	>1000	>1000
Buckwheat	Emergence	1000	>1000	>1000
	Biomass	1000	>1000	>1000
	Phytotoxicity	1000	>1000	>1000
Dwarf Bean	Emergence	1000	>1000	>1000
	Biomass	1000	>1000	>1000
	Phytotoxicity	1000	>1000	>1000
Ryegrass	Emergence	1000	>1000	>1000
	Biomass	1000	>1000	>1000
	Phytotoxicity	1000	>1000	>1000
Tomato	Emergence	1000	>1000	>1000
	Biomass	1000	>1000	>1000
	Phytotoxicity	1000	>1000	>1000

Description of key information

21-day EC₅₀ values of >1000 mg/kg dry soil and NOEC values of 1000 mg/kg dry soil (nominal concentrations) (highest concentration tested) have been determined for the effects of the test substance on seedling emergence, growth and phytotoxicity of wheat, turnip, buckwheat, dwarf bean, ryegrass and tomato.

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:

1 000 mg/kg soil dw

Additional information

Measured toxicity data are available for Shell GTL Solvent GS310 (Hydrocarbons, C18-C24, isoalkanes, < 2% aromatics) with six species of terrestrial higher plants: Turnip (Brassica rapa), Tomato (Solanum lycopersicum), Dwarf bean (Phaseolus vulgaris), Buckwheat (Fagopyrum esculentum), Wheat (Triticum aestivum) and Ryegrass (Lolium perenne) (Grzebisz, 2017). The test was conducted in accordance OECD Guideline 208 (Terrestrial Plants Test: Seedling Emergence and Seedling Growth Test).As the test substance was not readily soluble in water, it was applied to the test substrate using a sand carrier. Five test substance concentrations of 0 (control), 95, 172, 309, 556 and 1000 mg product/kg dry substrate were tested. No analysis of test concentrations was carried out. 

Assessment of effects on percent emergence, visual phytotoxicity and growth were conducted in comparison with the control treatment, after 21 days.

There was no effect of the test substance on emergence, biomass or phytotoxicity of any of the plants.

Therefore the EC₅₀, LOEC and NOEC values are >1000, >1000 and 1000 mg/kg soil dry weight, respectively, for the effects of the test substance on emergence, biomass and phytotoxicity of the six plant species.

In addition, a second study is available for Shell GTL Solvent GS 310 (Hydrocarbons, C18-C24, isoalkanes, < 2% aromatics) in six species of terrestrial higher plants: Onion (Allium cepa), maize (Zea mays), sugar beet (Beta vulgaris), oilseed rape (Brassica napus), soybean (Glycine max) and tomato (Lycopersicon esculentum) (Privitera, 2020). The test was conducted in accordance OECD Test Guideline 227 (Evaluation of the phytotoxicity to non-target terrestrial plants, vegetative vigour test). The objective of this study was to investigate the potential effects of GS310 when applied post-emergence to two monocotyledon and four dicotyledon terrestrial plant species. The six plant species were exposed to a deionised water control or one of five test item concentrations for 21 days and mortality and phytotoxicity were assessed weekly. In all the species tested, there was no effect on any of the endpoints measured up to the highest treatment rate of 15000 mL GS310/ha dry weight.

These data are supported by read-across data from two GTL-derived substances in the relevant carbon number range for Hydrocarbons, C18-C24, isoalkanes, <2% aromatics:

A seedling emergence and seeding growth test is available for GTL Gasoil (Goodband, 2011c). The test was conducted in accordance with OECD 208 and GLP, however no analytical monitoring of the test substance in the exposure medium was carried out. Five species of plant were tested. The lowest EC₅₀ was 990 mg/kg soil dry weight with perennial ryegrass (Lolium perenne) and the lowest NOEC was 560 mg/kg with mustard (Sinapis alba).

Five plant species; three dicotyledonous species, soybean (Glyicine max), tomato (Lycopersicon esulentum) and mustard (Sinapis alba) and two monocotyledonous species, oat (Avena sativa) and perennial ryegrass (Lolium perenne) were exposed to GTL Base Oil Distillates at concentrations of 100, 180, 320, 560 and 1000 mg/kg dw in a seedling emergence and growth test. The study was conducted according to OECD 208 and to GLP, however no analytical monitoring was carried out (Goodband, 2011d). The number of seedlings which emerged, mortalities and morphological abnormalities were recorded daily for 21 or 22 days after 50% emergence in the controls for each species. It was not possible to establish an EC₅₀ with these species and NOEC values have been reported to be at least 1000 mg/kg dw for all the organisms tested and across all endpoints.

Conclusion

Terrestrial plant toxicity data are available for the test substance and two GTL-derived substances in the relevant carbon number range for Hydrocarbons, C18-C24, isoalkanes, <2% aromatics. In the absence of adverse effects in any of these studies, it can be concluded that the NOEC for the registered substance is ≥1000 mg/kg dw soil.