Sodium 2-biphenylate

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Mar 2008 - Oct 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline test

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 100 mg/kg soil
- Sample storage conditions before analysis: samples were deep frozen until analysis

Vehicle:

yes

Details on preparation and application of test substrate:

- Method of mixing into soil (if used): the test substance was dissolved in acetone (25 mL) and subsequently mixed with quartz sand. Evaporation of the solvent over night.The sand was then mixed into the soil.
- Chemical name of vehicle: acetone
- Concentration of vehicle in test medium: 25 mL
- Evaporation of vehicle before use: yes

Species:

Brassica napus

Plant group:

Dicotyledonae (dicots)

Species:

Glycine max (G. soja)

Plant group:

Dicotyledonae (dicots)

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Test type:

seedling emergence toxicity test

Study type:

laboratory study

Substrate type:

natural soil

Limit test:

no

Total exposure duration:

14 d

Remarks:

after 50% seedling emergence in the control

Test temperature:

18.6 °C - 26.8 °C

Details on test conditions:

TEST SYSTEM
- Testing facility: growth chamber
- Test container: plastic pots, 12 cm diameter (A. sativa) and 14 cm diameter (G. max and B. napus)
- No. of seeds per container: 5
- No. of replicates per treatment group: 6
- No. of replicates per control: 6
- No. of replicates per vehicle control: 6

SOURCE AND PROPERTIES OF SUBSTRATE: LUFA 2.3
- Particle size: < 0.2 cm
- Soil taxonomic classification: sany loam
- Soil classification system: USDA
- Organic carbon (%): 0.99

GROWTH CONDITIONS
- Photoperiod: 16:8 h day-night regime
- Light intensity and quality: G. max: 7224 Lux; B. napus and A. sativa: 6454 Lux
- Day/night temperatures:
Brassica napus and Avena sativa:
mean day temperature: 25.4 °C
mean night temperature: 18.6 °C
Glycine max:
mean day temperature: 26.8 °C
mean night temperature: 18.9 °C
- Relative humidity (%): 59.3% - 63.5 %
- Watering regime and schedules: daily moisture check. Water was supplied when neccessary
- Any pest control method/fertilization (if used): After development of the first true leaves, 1 g/l Flory 9 “Hydro” (Planta) and 0.023 g/l Fetrilon 13 % (Compo) were added to the water one to three times a week, depending on the development of the plants.

EFFECT PARAMETERS MEASURED: Fresh weight: 14 days after 50% seedling emergence in the control; Germination: daily until 50% of the control plants had emerged; further checks were done weekly; Mortality: 14 days after 50% seedling emergence in the control; Phytotoxicity: weekly after 50% seedling emergence in the control; Growth stages (BBCH): 14 days after 50% seedling emergence in the control

Nominal and measured concentrations:

Nominal test substance concentrations:
control, solvent control, 3.13., 6.25, 12.5, 25.0, 50.0, 100 and 200 mg/kg soil dw (G. max)
control, solvent control, 12.5, 25.0, 50.0, 100 and 200 mg/kg soil dw (B. napus, A. sativa)
Recovery rate at 100 mg/kg soil: 93% and 98%

Species:

Avena sativa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

12.5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Species:

Avena sativa

Duration:

14 d

Dose descriptor:

EC50

Effect conc.:

53.9 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Species:

Brassica napus

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

25 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Species:

Brassica napus

Duration:

14 d

Dose descriptor:

EC50

Effect conc.:

62.9 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Species:

Glycine max (G. soja)

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

25 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Species:

Glycine max (G. soja)

Duration:

14 d

Dose descriptor:

EC50

Effect conc.:

89.7 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Details on results:

SEED GERMINATION
- Percent seed germination: B. napus: 93.3 - 100%; G. max: 86.7 - 100%; A. sativa: 80.0 - 96.7%
The most sensitive species was Avena sativa followed by Brassica napus. the least sensistive species was Glycine max.
The germination rate was not significantly affected by the substance

FRESH WEIGHTS:
- Brassica napus: The fresh weight was statistically significantly reduced at 50.0 and 100 mg/kg (22.6% and 93.5%).
- Glycine max: The fresh weight was reduced at all tested concentrations (0.5 to 83.7%). This reduction was statistically significant at 50.0 mg 2-Phenylphenol/kg and at higher concentrations (34.0% to 83.7%).
- Avena sativa: The fresh weight was reduced at all tested concentrations (8.6% to 92.8%). This reduction was statistically significant from 25.0 mg/kg upwards.

GROWTH STAGES:
- Brassica napus: The plant development was delayed at 50.0 and 100 mg/kg (growth stages at test end: BBCH 13 to 14 in the controls, BBCH 13 (14) at 50.0 mg/kg and BBCH 11 to 12 (13) at 100 mg/kg)
- Glycine max: The plant development was delayed at a concentration of 100 and 200 mg/kg (growth stages at test end: BBCH 13 to 14 in the control, BBCH 13 (14) at 100 mg/kg and BBCH 12 (13) at 200 mg/kg).
- Avena sativa: The plant development was delayed compared to the controls at 12.5 mg/kg and at higher concentrations (growth stages at test end: BBCH 12 to 13 in the controls, BBCH 12 (13) at 12.5 mg/kg, BBCH 12 at 25.0 and 50.0 mg/kg and BBCH 11 at 100 mg/kg).

PHYTOTOXIC EFFECTS:
- Brassica napus: Phytotoxic effects were chlorosis, necrosis and growth reduction from 25.0 mg/kg upwards. At 12.5 and 25.0 mg/kg some seedlings show slight deformations of the leaves.
- Glycine max: Distinct phytotoxic effects were growth reduction from 100.0 mg/kg soil dry weight upwards and additionally deformation of leaves and stems at 200 mg/kg.
- Avena sativa: Phytotoxic effects were necrosis and growth reduction from 50.0 mg/kg upwards. At 100.0 mg/kg the seedlings of one pot showed discoloration of the leaves.

Reported statistics and error estimates:

Statistical analysis of the control plants and solvent control plants:
Fresh weight data of the control and solvent control plants were tested for normal distribution and homogeneity of variance using the Kolmogoroff-Smirnov-Test (α = 0.05) and the Cochran-Test (α = 0.05). Because the data were normally distributed and homogeneous the Student-t-test (pairwise comparison, two-sided, α = 0.05) was used.
For the germination data Fisher’s Exact-Test was used (two-sided, α = 0.05).
Because there was no statistical difference between the data of the control plants and solvent control plants the results of the plants treated with the tested concentrations were compared with the results of the solvent control plants.
Statistical analysis of the plants treated with the tested concentrations and the solvent control plants:
Fresh weight data were tested for normal distribution and homogeneity of variance using the Kolmogoroff-Smirnov-Test (α = 0.05) and the Cochran-Test (α = 0.05). Because the data were normally distributed and homogeneous the Dunnett Test (multiple comparison, two-sided, α = 0.05) was used for comparing treatment groups and solvent control.
In order to determine the EC25 and EC50 values, a regression analysis was performed (Probit analysis).
For the mortality and germination data Fisher’s Exact Test (two-sided, α = 0.05) was used.
The computer programs used to perform the statistical analyses were ToxRat Professional, Version 2.09, ToxRat® Solutions GmbH © 2001-2005.

Reference 2

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please refer to analogue justification provided in IUCLID section 13

Reason / purpose for cross-reference:

read-across source

Species:

Avena sativa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

12.5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Species:

Allium cepa

Duration:

14 d

Dose descriptor:

EC50

Effect conc.:

53.9 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Species:

Brassica napus

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

25 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Species:

Brassica napus

Duration:

14 d

Dose descriptor:

EC50

Effect conc.:

62.9 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Species:

Glycine max (G. soja)

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

25 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Species:

Glycine max (G. soja)

Duration:

14 d

Dose descriptor:

EC50

Effect conc.:

89.7 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Reference 3

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

11 to 28 Oct 2005

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.4100 (Terrestrial Plant Toxicity Tier I (seedling emergence))

Version / remarks:

draft

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.4225 (Seedling Emergence Tier II)

Version / remarks:

draft

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 3 samples were prepared for quality control (concentration 1010 mg a.i./L)

Vehicle:

no

Details on preparation and application of test substrate:

- Method of application: overspray of the substrate.
On the day of test initiation, a 1000 mg a.i./L nominal test solution was prepared by placing 1.4064 g (1.0053 gas active ingredient) in a 1 L volumetric flask and bringing it to volume withdeionized water. The OPP/SOPP solution was applied to the substrate surface by calibrating the spray apparatus to deliver the 1000 mg a.i./L solution at a rate of 25 galllons/Acre or 0.00869 L per tray.

Species:

Oryza sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Rice
- Plant family: Poaceae
- Variety: Japonica
- Source of seed: Pioneer Seed, Johnston, Iowa, USA
- Seed storage: stored refrigerated at approximately 4 °C in the dark

Test type:

vegetative vigour test

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

yes

Total exposure duration:

14 d

Test temperature:

20 to 37 °C

Details on test conditions:

TEST SYSTEM
- Testing facility: greenhouse
- Test container (type, material, size): polypropylene pots H: 13 cm; Ø top: 13 cm, bottom 9cm
- Amount of soil: 1.5 kg, surface area= 104 cm²
- Method of seeding: seeds were planted at a depth of 1 cm
- No. of seeds per container: 5
- No. of replicates per treatment group: 6
- No. of replicates per control: 6


SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Composition (if artificial substrate): Loam Fairhaven, Massachusetts (SSL Lot No. 063001) mixed with silica sand (Wedron Silica, Wedron, Illinois, SSL Lot No. 060701); 85% sand,12% silt, 3% clay
- Organic carbon (%): 1.1%

GROWTH CONDITIONS
- Photoperiod: 16 hours light/8 hours dark
- Light source: natural light and sodium vapor lights
- Light intensity and quality: 3100 - 9700 Lux
- Relative humidity (%): 61
- Watering regime and schedules: 200 mg/L Peters 20-20-20 (SSL No. 22102, supplied by Griffin Greenhouse Supplier). Approximately 100 mL was provided to all pots by sub-irrigation twice weekly. All additional watering was provided using town well water.


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : inhibition of emergence, shoot length and shoot dry weight and treatment-related morphological abnormalities. Effects on seedling emergence were evaluated 10 and 14 days after the application. Shoot length and dry shoot weight were evaluated on day 14.


TEST CONCENTRATIONS
- Range finding study: yes
- Test concentrations: 0.10, 1.0, 10, 100 and 1000 mg a.i./L
- Results used to determine the conditions for the definitive study: Since the range-finding test determined the percent reduction at 1000 mg a.i./L did not exceed 25%, a Tier I study at a nominal concentration of 1000 mg a.i./L was conducted.

Nominal and measured concentrations:

Nominal test substance concentration: 1000 mg a.i./L, applied to the substrate surface at a rate of 25 gal/A or 0.00869 L per tray.
Mean measured concentration: 1000 mg a.i./L (100% of nominal)

Species:

Oryza sativa

Duration:

14 d

Dose descriptor:

other: Percent inhibition from control

Effect conc.:

7 other: %

Nominal / measured:

not specified

Conc. based on:

not specified

Basis for effect:

other: emergence

Species:

Oryza sativa

Duration:

14 d

Dose descriptor:

other: Percent inhibition from control

Effect conc.:

4.5 other: %

Nominal / measured:

not specified

Conc. based on:

not specified

Basis for effect:

other: shoot length

Species:

Oryza sativa

Duration:

14 d

Dose descriptor:

other: Percent inhibition from control

Effect conc.:

2 other: %

Nominal / measured:

not specified

Conc. based on:

not specified

Basis for effect:

other: dry shoot weight

Details on results:

No plants with morphological abnormalities were observed in the control or the application rate tested. One non-emerged plant was observed in the control, while three non-emerged plants were observed in the application rate tested.

Reference 4

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

11 to 28 Oct 2005

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.4150 (Terrestrial Plant Toxicity Tier I (vegetative vigor))

Version / remarks:

draft

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.4250 (Vegetative Vigor Tier II)

Version / remarks:

draft

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 3 samples were prepared for quality control (concentration 1010 mg a.i./L)

Vehicle:

no

Details on preparation and application of test substrate:

- Method of application: overspray of foliage at 2- to 4-leaf stage
On the day of test initiation, a 1000 mg a.i./L nominal test solution was prepared by placing 1.4064 g (1.0053 gas active ingredient) in a 1 L volumetric flask and bringing it to volume withdeionized water. The OPP/SOPP solution was applied to the foliar surface by calibrating the spray apparatus to deliver the 1000 mg a.i./L solution at a rate of 25 gallons/Acre 0.00869 L per tray.

Species:

Oryza sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Rice
- Plant family: Poaceae
- Variety: Japonica
- Source of seed: Pioneer Seed, Johnston, Iowa, USA
- Seed storage: stored refrigerated at approximately 4 °C in the dark

Test type:

vegetative vigour test

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

yes

Total exposure duration:

14 d

Test temperature:

20 to 37 °C

Details on test conditions:

TEST SYSTEM
- Testing facility: greenhouse
- Test container (type, material, size): polypropylene pots H: 13 cm; Ø top: 13 cm, bottom 9 cm
- Amount of soil: 1.5 kg, surface area= 104 cm²
- Method of seeding: seeds were planted at a depth of 1 cm
- No. of seeds per container: 5
- No. of replicates per treatment group: 6
- No. of replicates per control: 6

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Composition (if artificial substrate): Loam Fairhaven, Massachusetts (SSL Lot No. 063001) mixed with silica sand (Wedron Silica, Wedron, Illinois, SSL Lot No. 060701); 85% sand,12% silt, 3% clay
- Organic carbon (%): 1.1%

GROWTH CONDITIONS
- Photoperiod: 16 hours light/8 hours dark
- Light source: natural light and sodium vapor lights
- Light intensity and quality: 3600 - 13 000 Lux
- Relative humidity (%): 65
- Watering regime and schedules: 200 mg/L Peters 20-20-20 (SSL No. 22102, supplied by Griffin Greenhouse Supplier). Approximately 100 mL was provided to all pots by sub-irrigation twice weekly. All additional watering was provided using town well water.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : shoot length and shoot dry weight and treatment-related morphological abnormalities. Effects on dhoot length were evaluated 7 and 14 days after application. Dry shoot weight were evaluated on day 14.

TEST CONCENTRATIONS
- Range finding study: yes
- Test concentrations: 0.10, 1.0, 10, 100 and 1000 mg a.i./L
- Results used to determine the conditions for the definitive study: Since the range-finding test determined the percent reduction at 1000 mg a.i./L did not exceed 25%, a Tier I study at a nominal concentration of 1000 mg a.i./L was conducted.

Nominal and measured concentrations:

Nominal test substance concentration: 1000 mg a.i./L, applied to the foliar surface at a rate of 25 gal/A or 0.00869 L per tray.
Mean measured concentration: 1000 mg a.i./L (100% of nominal)

Reference substance (positive control):

no

Species:

Oryza sativa

Duration:

7 d

Dose descriptor:

other: Percent inhibition from control

Effect conc.:

5 other: %

Nominal / measured:

not specified

Conc. based on:

not specified

Basis for effect:

other: shoot length

Species:

Oryza sativa

Duration:

14 d

Dose descriptor:

other: Percent inhibition from control

Effect conc.:

-2 other: %

Nominal / measured:

not specified

Conc. based on:

not specified

Basis for effect:

other: shoot length

Species:

Oryza sativa

Duration:

14 d

Dose descriptor:

other: Percent inhibition from control

Effect conc.:

2 other: %

Nominal / measured:

not specified

Conc. based on:

not specified

Basis for effect:

other: dry shoot weight

Details on results:

No dead plants or plants with morphological abnormalities were observed in the control or the application rate tested. The 7- and 14-day shoot length and dry shoot weight were decreased by 5, -2 and 2%, respectively. Exposure to OPP/SOPP at a nominal concentration equal to the maximum application rate, 1000 mg a.i./L, did not cause adverse results equal to or exceeding 25%.

Description of key information

EC50 = 53.9 mg/kg soil dw; NOEC = 12.5 mg/kg soil dw for Avena sativa based on fresh weight

EC50 = 62.9 mg/kg soil dw; NOEC = 25 mg/kg soil dw for Brassica napus based on fresh weight

EC50 = 89.7 mg/kg soil dw, NOEC = 25 mg/kg soil dw for Glycine max based on fresh weight

Key value for chemical safety assessment

Short-term EC50 or LC50 for terrestrial plants:

53.9 mg/kg soil dw

Additional information

Reliable tests on the toxicity of sodium 2-biphenylate (CAS 132-27-4) and the read across substance 2-phenylphenol (CAS 90-43-7) to terrestrial plants are available. The key information for evaluation of the toxicity to plants was obtained from the read across study on 2-phenylphenol (CAS 90-43-7). The toxicity of the substance was tested with three plant species of three different families: Brassica napus, Glycine max and Avena sativa (Bützler & Meinerling 2008). The test was performed for 14 days in a growth chamber under controlled test conditions and the plants were exposed to concentrations between 12.5 and 100 mg 2-Phenylphenol/kg dry soil according to OECD Guideline 208. The concentrations in the test with Glycine max ranged from to 200 mg test item/kg dry soil. Test parameters were germination rate, mortality and phytotoxicity.

Phytotoxic effects observed were growth reduction (all species), slight chlorosis (Brassica napus and Glycine max) and slight necrosis (all species). Additionally, Brassica napus showed abnormal growth of the leaves, and Glycine max showed abnormal growth of the leaves and the stems.

The most sensitive species in terms of fresh weight was Avena sativa with EC50 value of 53.9 mg/kg soil dry weight and NOEC 12.5 mg/kg soil dry weight. It was followed by Brassica napus (EC50 62.9 and NOEC 25 mg/kg soil dry weight). The least sensitive species was Glycine max which showed an EC50 value of 89.7 and NOEC 25 mg/kg soil dry weight.

Supporting information is available for the target substance sodium 2-biphenylate (CAS 132-27-4). The effect of sodium 2-biphenylate on the seedling emergence of Oryza sativa was investigated in a study following EPA OPPTS 850.4100 (Terrestrial Plant Toxicity Tier I (seedling emergence)) and EPA OPPTS 850.4225 (Seedling Emergence Tier II) (Teixeira 2006a). Seeds of Oryza sativa were sown in artificial soil. The test substance was applied to the substrate surface at a concentration of 1000 mg a.i./L, at a rate of 25 gal/A or 0.00869 L per tray. The inhibition of emergence and treatment-related morphological abnormalities were evaluated after ten and 14 days. The shoot length and shoot dry weight were determined after test termination. No plants with morphological abnormalities were observed in the control or the application rate tested. One non-emerged plant was observed in the control, while three non-emerged plants were observed in the application rate tested.

A second study investigated the effects of sodium 2-biphenylate on Oryza sativa when applied on the foliar surface. The study followed EPA OPPTS 850.4150 (Terrestrial Plant Toxicity Tier I (vegetative vigor)) and EPA OPPTS 850.4250 (Vegetative Vigor Tier II) (Teixeira 2006b). The study was conducted as a limit test with a test substance concentration of 1000 mg a.i./L, applied to the foliar surface at a rate of 25 galllons/Acre or 0.00869 L per tray. The test substance was applied when the plants had reached the 2- to 4 -leaf stage. The plant development was followed for 14 consecutive days. Dead plants or plants with morphological abnormalities were observed. The 7- and 14-day shoot length and dry shoot weight were decreased by 5, -2 and 2%, respectively. Exposure to OPP/SOPP at a nominal concentration equal to the maximum application rate, 1000 mg a.i./L, did not cause adverse results equal to or exceeding 25%.