4-mesyl-2-nitrotoluene

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to terrestrial plants: long-term

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Reference 2

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 Jan 2005 to 10 Feb 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant, guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Samples were taken from stock solutions (50898 ppm NMST) and control.
- Sampling method: Triplicate samples were taken from the stock solution and a single sample from the control.
- Sample storage conditions before analysis: Not reported

Vehicle:

yes

Details on preparation and application of test substrate:

- Method of mixing into soil (if used): Stock solutions (pre-mixed with 200 g sand and 100 g bulk artificial soil) mixed with bulk soil in a soil mixer
- Controls: Blank and vehicle control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Acetone
- Concentration of vehicle in test medium (stock solution and final test solution): Not reported
- Evaporation of vehicle before use: Not reported

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Oats
- Plant family: Poaceae
- Variety: Armor
- Source of seed: Gries Seed Farm Inc., Fremont, OH, USA
- Prior seed treatment/sterilization: None
- Historical germination of seed (germination of seed lot tested): Not reported
- Seed storage: Not reported

Species:

Brassica napus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Oilseed Rape
- Plant family: Brassicaceae
- Variety: None provided
- Source of seed: Johnny's Selected Seeds, Winslow, ME, USA
- Prior seed treatment/sterilization: None
- Historical germination of seed (germination of seed lot tested): Not reported
- Seed storage: Not reported

Species:

Pisum sativum

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Pea
- Plant family: Fabaceae
- Variety: Laxton Progress #9
- Source of seed: Mayer Quality Seeds, Baltimore, MD, USA
- Prior seed treatment/sterilization: None
- Historical germination of seed (germination of seed lot tested): Not reported
- Seed storage: Not reported

Test type:

seedling emergence toxicity test

Study type:

semi-field study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

21 d

Test temperature:

Min: 16.70 °C, Max: 26.96 °C, Mean: 20.50 °C, SD: 0.63 °C

pH:

7.4

Moisture:

Not reported

Details on test conditions:

TEST SYSTEM
- Testing facility: Wildlife International Ltd. glasshouse facility
- Test container (type, material, size): Plastic pots, 16 cm in diameter, 12 cm deep
- Amount of soil: 1940 cm3 per pot
- Method of seeding: Template used to gently compact the soil and leave ten uniform holes. One seed was then planted in each hole. A. sativa and P. sativum seeds were planted at an approximate depth of 20 mm, while B. napus seeds were planted at an approximate depth of 6 mm.
- No. of seeds per container: 10
- No. of plants (retained after thinning): No thinning reported.
- No. of replicates per treatment group: 4
- No. of replicates per control: 4
- No. of replicates per vehicle control: 4

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Collection procedures: Not applicable, artifical soil
- Composition (if artificial substrate): 50% sand, 29% silt, 21% clay, organic matter 1.7%
- Organic carbon (%): 1.0%
- Maximum water holding capacity (in % dry weigth): Not reported
- CEC: Not reported
- Pretreatment of soil: Not reported
- Storage (condition, duration): Not reported

NUTRIENT MEDIUM (if used)
- Description: A slow-release fertilizer was added to provide nutrients essential for plant growth

GROWTH CONDITIONS
- Photoperiod: 16 hours light minimum
- Light source: Natural + Artificial (high-pressure sodium)
- Light intensity and quality: Min: 7.9 moles photosynthetically active radiation/day, Max: 17.9 moles photosynthetically active radiation/day, Mean: 13.7 moles photosynthetically active radiation/day, SD: 2.9 moles photosynthetically active radiation/day.
- Day/night temperatures: Daily maxima and minima reported.
Min: 16.70 °C, Max: 16.96 °C, Mean: 20.50 °C, SD: 0.63 °C
- Relative humidity (%):
Min: 11.06 %. Max: 55.08 %, Mean: 27.52 %, SD: 6.95 %.
- Wind velocity: Not applicable
- Air exchange rate: Not reported.
- Watering regime and schedules:
- Water source/type: Well water from glasshouse facility
- Volume applied: Not reported
- Interval of applications:
B. napus and A. sativa: Days 1, 5, 9, 12, 14, 16, 18, 20, 21
P. sativum: Days 2, 5, 10, 14, 18, 21
- Method of application: Subirrigation
- Any pest control method/fertilization (if used): Not reported

ACCLIMATION PERIOD: Not applicable

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Seedling emergence at Days 7, 14 and at test termination. Seedling growth (dry weight, height), survival and condition measured at test termination.

- Phytotoxicity rating system (if used): 0 - 100 Rating scale adapted from: Frans, Robert E. and Ronald E. Talbert. 1977. Design of Field Experiments and the Measurement and Analysis of Plant Responses. Pages 15-23 in B. Truelove, ed. Research Methods in Weed Science. Southern Weed Science Society, Auburn University, Alabama.

VEHICLE CONTROL PERFORMED: Yes, acetone solvent only

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10
- Justification for using less concentrations than requested by guideline: Not applicable
- Test concentrations: 0, 10, 100 mg test substance/kg soil dry weight

Nominal and measured concentrations:

0, 10, 100 mg test substance/kg soil dry weight
Analytical monitoring of the stock solution returned values at 101% of nominal (see Table 1). Results are reported as nominal concentrations

Reference substance (positive control):

no

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: survival

Species:

Avena sativa

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: survival

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: survival

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

height

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

10 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

height

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

44.6 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

height

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

10 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

biomass

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

1 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

biomass

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

13.9 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

biomass

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: survival

Species:

Brassica napus

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: survival

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

55 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: survival

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

10 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

height

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

1 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

height

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

10.1 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

height

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

10 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

biomass

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

1 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

biomass

Species:

Brassica napus

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

50.5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

biomass

Species:

Pisum sativum

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Species:

Pisum sativum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Species:

Pisum sativum

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Species:

Pisum sativum

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: survival

Species:

Pisum sativum

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: survival

Species:

Pisum sativum

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: survival

Species:

Pisum sativum

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

height

Species:

Pisum sativum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

10 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

height

Species:

Pisum sativum

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

66.8 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

height

Species:

Pisum sativum

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

biomass

Species:

Pisum sativum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

10 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

biomass

Species:

Pisum sativum

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

50.5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

biomass

Details on results:

SEED GERMINATION
- Percent seed germination: Not reported
- Root length: Not reported
- Root discolouration/malformation: Not reported

SEEDLING EMERGENCE
- Percent seedling emergence: Observed. Defined as the presence of visible plant tissue at the surface of the soil.
- Percent survival: Observed.
- Plant height: Seedling height was measured with a ruler to the nearest whole centimeter from the surface of the soil to the tip of the tallest leaf
- Dry weight: Measured.
- Abnormal seed development or appearance: Seedling condition assessed on rating system (Table 2), considering all relevant observable characteristics.

INJURY RATING SYSTEM: See table 2

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Dunnett's test was used to establish the LOEC and NOECby determining which treatment groups differed significantly (p<0.05) from the control group. Mean seedling emergence, survival, biomass, and height of the control and treatment groups were compared using the DUNNETT option of the GLM (general linear model) procedure of SAS (SAS Institiute 1999).

Determination of effect rates (ER estimates) and their confidence limits was done using the non-linear regression analysis of Bruce and Versteeg
(Bruce and Versteeg 1992) when reductions in test endpoints among one or more treatment groups were 25% or more relative to control means. Analyses were conducted using the NLIN procedure of SAS. ER25 and ER50 were defined as the test substance application rates that caused an 25%/50% change in the treatment group mean emergence, survival, dry weight or height relative to the control group. ERx estimates were calculated using nominal test concentrations and treatment group mean values with the following equation:

if C > 0 R= R0 * ¿[(log(ERx)-log(C))/¿ +Zx]
if C = 0 R= R0

where:
R = the predicted biotic response at concentration C
R0 = the predicted biotic response for controls
¿[ ] = the cumulative area under the standard, normal distribution
log(ERx) = the logarithm of the predicted ER giving an x percentage of decrease in the biological parameter vs. the
control
Zx = the normal deviate above which x percentage of the area of the standard normal distribution lies.
¿ = the standard deviation of the normal distribution

ERx estimates were not calculated for plant condition because those data are qualitative and therefore not conducive to statistical analysis.

Table 3: Effect Endpoints

Species	21-Day Emergence (mg/kg d.w.)			21-Day Survival (mg/kg d.w.)			21-day Height (mg/kg d.w.)			21-day Biomass (mg/kg d.w.)
	LOEC	NOEC	EC50	LOEC	NOEC	EC50	LOEC	NOEC	EC50	LOEC	NOEC	EC50
Monocot:
Avena sativa (oat)	>100	100	>100	>100	100	>100	100	10	44.6	10	1	13.9
Dicots:
Brassica napus (oilseed rape)	>100	100	>100	100	10	55	10	1	10.1	10	1	8.82
Pisum sativum (pea)	>100	100	>100	>100	100	>100	100	10	66.8	100	10	50.5

Detailed data on each species is provided in the study report

P.sativum seedlings showed no signs of phytotoxicity. In the 10 mg/kg d.w. group A. sativa showed slight necrosis which was accompanied by slight leaf curl in the 100 mg/kg d.w. treatment group. B. napus showed chlorosis and necrosis in the 10 mg/kg d.w. treatment group and total mortality in the 100 mg/kg d.w. treatment group.

Validity criteria fulfilled:

not specified

Conclusions:

The effects of the test substance was evaluated on the seedling emergence of 3 species of non-target plants. A pre-emergence soil concentration of up to 100 mg/kg soil d.w. resulted in effects on all test species. The most sensitive case was Brassica napus which showed 21 day biomass NOEC and EC50 of 1 and 8.82 mg/kg.

Executive summary:

Seeds of three species of non-target plants (A. sativa, B. napus and P. sativum) were planted in soils containing the test substance in concentrations of 1, 10 and 100 mg/kg soil d.w. as well as blank and solvent controls. Seedlings were measured for emergence, survival, height and biomass. No significant differences were measured between the solvent and blank controls. Treatment-related effects were observed in all species, with 21-day biomass being the most sensitive endpoint. The most sensitive species was Brassica napus which showed 21-day biomass NOEC and EC₅₀of 1 and 8.82 mg/kg.

Description of key information

EC50(biomass) = 13.9 mg/kg soil d.wt., NOEC(biomass)=1 mg/kg soil d.wt., Avena sativa, 21 days, OECD 208, Porch 2005

Key value for chemical safety assessment

Short-term EC50 or LC50 for terrestrial plants:

8.82 mg/kg soil dw

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

1 mg/kg soil dw

Additional information

Seeds of three species of non-target plants (A. sativa, B. napus and P. sativum) were planted in soils containing the test substance in concentrations of 1, 10 and 100 mg/kg soil d.w. as well as blank and solvent controls. Seedlings were measured for emergence, survival, height and biomass. No significant differences were measured between the solvent and blank controls. Treatment-related effects were observed in all species, with 21-day biomass being the most sensitive endpoint. The most sensitive species (Avena sativa) showed 21-day biomass EC50=13.9 mg/kg soil d.wt. and NOEC=1 mg/kg soil d.wt.

The available study covers a sensitive stage in the life-cycle of a plant, and has thus been used as an estimate of chronic toxicity (Chapter R.7c, R.7.11.3.1). The study is considered to be reliable and adequate for risk assessment.