2-(2-butoxyethoxy)ethyl 6-propylpiperonyl ether

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Reference 1

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:

21.3.2011-26.6.2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.4225 (Seedling Emergence Tier II)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Lot No. AB1970
Expiration date: 2.12.2012

Analytical monitoring:

no

Remarks:

No analytical monitoring was performed during the study, but the stock solution was measured at start.

Details on sampling:

- Concentrations: 6.0 lb PBO/A, equivalent to 6,725,080 mg PBO/ha.
- Sampling method: A stock solution was prepared from the test item to contain a nominal of 9.6000 g PBO/L. The measured content was 9.2 g PBO/L (92% of the nominal). Results are reported as nominal values.
- Sample storage conditions before analysis: Room temperature, original container, dark ventilated conditions.

Vehicle:

yes

Remarks:

The test material was dissolved in acetone and the stock solution was applied with a sprayer to the pots containing the soil.

Details on preparation and application of test substrate:

A stock solution was prepared from the test item by dissolving it in acetone (16.9492 g/L). The stock solution contained a nominal of 9.6 mg PBO/mL.
The pots containing the soil were arranged on trays of 0.3716 m² size.
Per tray, 26.08 mL of the stock solution (equivalent to 250.37 mg PBO) was applied with a sprayer.

Pots were 12 cm tall with a top diamter of 14 cm and a bottom diameter of 12 cm. Each pot interior base was fitted with a filter paper and was then filled with 1.2 kg of untreated soil.

Test species were planted at a depth of 1 to 2 cm below the soil surface.

Species:

Lycopersicon esculentum

Plant group:

Dicotyledonae (dicots)

Species:

Raphanus sativus

Plant group:

Dicotyledonae (dicots)

Species:

Glycine max (G. soja)

Plant group:

Dicotyledonae (dicots)

Species:

Brassica napus

Plant group:

Dicotyledonae (dicots)

Species:

Cucumis sativus

Plant group:

Dicotyledonae (dicots)

Species:

Phaseolus vulgaris

Plant group:

Dicotyledonae (dicots)

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Species:

Lolium perenne

Plant group:

Monocotyledonae (monocots)

Species:

Allium cepa

Plant group:

Monocotyledonae (monocots)

Species:

Zea mays

Plant group:

Monocotyledonae (monocots)

Test type:

seedling emergence and seedling growth test

Study type:

other: greenhouse

Substrate type:

natural soil

Remarks:

Natural soil mixed with washed sand (3:1).

Limit test:

no

Total exposure duration:

14 d

Remarks:

Measurements at 7 and 14 days.

Post exposure observation period:

None

Test temperature:

20-36°C during the day
18-23°C during the night

Moisture:

Relative humidity in the greenhouse was 45%.
Each pot was placed in a polypropylene saucer and received ca. 100 mL a fertilizer solution via sub-irrigation (through the filter paper).

Nominal and measured concentrations:

The measured content was 9.2 g PBO/L (92% of the nominal).
This is equivalent to
Results are reported as nominal values.

Reference substance (positive control):

no

Key result

Species:

Brassica rapa

Duration:

14 d

Dose descriptor:

other: morphological abnormalities

Effect conc.:

6 725.08 g/ha

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: dead plant

Remarks on result:

other: Only in this test species one dead plant was observed. This resultet in a mean rating for abnormalities of 4 (out of 100).

Key result

Species:

Brassica napus

Duration:

14 d

Dose descriptor:

other: %inhibition of dry shoot weight relative to the control

Effect conc.:

6 725.08 g/ha

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: dry shoot length

Remarks on result:

other: The highest percentage of inhibition of dry shoot weight was observed with this test species and amounted to 13% inhibition relative to the control.

Key result

Species:

Raphanus sativus

Duration:

14 d

Dose descriptor:

other: % inhibition of shoot length relative to the control

Effect conc.:

6 725.08 g/ha

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: shoot length

Remarks on result:

other: The highest percentage of inhibition of shoot length was observed with this test species and amounted to 12% inhibition relative to the control.

Key result

Species:

Lycopersicon esculentum

Duration:

14 d

Dose descriptor:

other: % inhibition of seedling emergence relative to the control.

Effect conc.:

6 725.08 g/ha

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

seedling emergence

Remarks on result:

other: The highest percentage of inhibition of seedling emergence was observed with this test species and amounted to 4% inhibition relative to the control.

Details on results:

SEEDLING EMERGENCE
- Percent seedling emergence: Inhibition relative to control ranged from -20% to 4% (max. tomato).
- Percent survival: 100%
- Plant height: Inhibition relative to control ranged from -26% to 12% (max. radish).
- Dry weight: Inhibition relative to control ranged from -28% to 13% (max. onion).
- Other effects: One dead plant was observed in one test species.

Reported statistics and error estimates:

A t-Test was conducted to compare oercent emerence, shoot length and dry shoot weight of the control to the solvent control data. Percent inhibition and effect analysis was calculated relative to the control data.

Validity criteria fulfilled:

yes

Conclusions:

The percent reduction of percent emergence, shoot length and shoot dry weight for ten species was < 25% at the application rate of 6725.08 g PBO/ha. These results meet the acceptance criteria for Tier I and no further testing was performed.

Executive summary:

The percent reduction of percent emergence, shoot length and shoot dry weight for ten species was < 25% at the application rate of 6725.08 g PBO/ha. These results meet the acceptance criteria for Tier I and no further testing was performed.

Reference 2

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Details on sampling:

The condition of test plants was assessed weekly after the application. Phytotoxicity was assessed 7, 14 and 21 days after application. The effects on plant fresh and dry weight were determined at test termination.
Samples were frozen within 10 minutes after the application and one of them sent to the analytical Principal Investigator for check of the concentration of the active ingredient. Samples were shipped on 21 March 2006, arrival on 23 March 2006 with dry ice remaining.

Vehicle:

no

Species:

Glycine max (G. soja)

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Family: Fabaceae
Common name: soybean
Source (seed/plant): KWS Saat AG

Species:

Cucumis sativus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Family: Cucurbitaceae
Common name: cucumber
Source (seed/plant): Rainbow

Species:

Helianthus annuus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Family: Asteraceae
Common name: sunflower
Source (seed/plant): KWS Saat AG

Species:

Beta vulgaris

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Family: Chenopodiaceae
Common name: sugarbeet
Source (seed/plant): KWS Saat AG

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

Family: Poaceae
Common name: oat
Source (seed/plant): Agrosa Semillas

Species:

Allium cepa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

Family: Liliaceae
Common name: onion
Source (seed/plant): Demeter

Test type:

vegetative vigour test

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

yes

Total exposure duration:

21 d

Test temperature:

16/22°C

Details on test conditions:

TEST SYSTEM
- Test type: Polycarbonate greenhouse, floor area 400 m2
- Container type: Plastic pots approximately 15 cm in diameter and 12 cm in height
- Seed germination potential: Information not included
- Identification of the plant species: Lot number: 240204, 050-0008, 240204, WA/ZR 11313, 081105, 0462804, respectively
- Number of replicates (= pots): 15 for G. max, C. sativus, H. annuus, B. vulgaris; 6 for A. sativa, A. cepa
- Numbers of plants per replicate per dose: 2 for G. max, C. sativus, H. annuus, B. vulgaris; 5 for A. sativa, A. cepa
- Date of sowing: 17 Jan 06: B. vulgaris; G. max; H annuus, A. sativa; 13 Jan 06: C. sativus; 22 Dec 06: A. cepa
- Plant density: 2-5 plants per pot
- Date of test substance application: 15 Feb 2006: H. annuus, B. vulgaris, A. cepa, A. sativa; 22 Feb 2006 : G. max, C. sativus
- Growth stage of plants at application: BBCH 12-14
- Date of phytotoxicity rating or harvest: Phytotoxic main adverse effects (i.e. chlorosis, stunted growth, wilting, discoloration, necrosis) were assessed 7, 14 and 21 days after application.
- Dates of analysis: At the final assessment 21 days after application, the shoot fresh weight was determined for all plants of one replicate as a batch sample.

TEST CONDITIONS
- Test type: Fully controlled greenhouse
- Method of application: Application was performed in a closed spray cabin with a spray surface of 10880 cm2 (128 cm x 85 cm). Plants were treated with a flat fan nozzle (teejet R 11003 VS) at a spray pressure of 2.0 bar, the distance to the plant surface was approximately 35 cm. The output per surface corresponded to 300 L/ha ± 10%.
- Application levels: Spray solution of the higher rate was prepared by dissolving 6.565 g PB80 EC-NF in 500 mL deionised water, of the lower rate by adding 105 mL of the stock solution to 245 mL deionised water
- Dose rates: 975 g a.i. piperonylbutoxide/ha; 3250 g a.i. piperonylbutoxide/ha
- Substrate characteristics: Heat treated soil mixed with sand and adjusted to the required pH. The soil consisted of 83% sand, 7% silt, and 10% clay, with a pH of 6.9 and a total organic carbon content of 0.75% sieved to a particle size of 5 mm after slightly drying.
- Watering of the plants: The control and test item pots were irrigated with a water and nutrient source located at the bottom of each pot. A cotton strip connected soil and water source. The water consumed was controlled regularly and missing water supplemented. No plant protection measures were performed over the whole testing period.
- Temperature: 6/22°C
- Thermoperiod: Data not included
- Light regime: The photoperiod was 16 h light and 8 h dark. Natural light was complemented by high pressure sodium lamps to maintain a light intensity of 5000– 22000 lux.
- Relative humidity: 45-94%
- Wind volatility: Data not included
- Observation periods and duration of test: Observations were made during the test to document plant condition and growth. The condition of test plants was assessed weekly after application.
- Pest control: Soil and sand had not been subjected to any pesticide or organic fertiliser treatment for at least 3 years prior to collection and until use within this study. No plant protection measures were performed over the whole testing period.
- Any other treatments and procedures: No further procedures mentioned

Key result

Species:

Cucumis sativus

Duration:

21 d

Dose descriptor:

other: visual assessment %

Remarks:

74.67%

Effect conc.:

>= 975 - <= 3 250 g/ha

Nominal / measured:

nominal

Basis for effect:

phytotoxicity

Key result

Species:

Glycine max (G. soja)

Duration:

21 d

Dose descriptor:

other: visual assessment %

Remarks:

67.33%

Effect conc.:

>= 975 - <= 3 250 g/ha

Nominal / measured:

nominal

Basis for effect:

phytotoxicity

Details on results:

RESULTS TEST SUBSTANCE
- Applied initial concentration: Calculated concentrations: 3295 and 10982 mg a.i./L equivalent to an initial measured average concentration of 2648 and 9013 mg a.i./L, respectively.
- Phytotoxicity rating: Chlorosis was observed for Beta vulgaris, Cucumis sativus, Helianthus annuus and Glycine max. Stunting was observed for Cucumis sativus. The maximum average damage (according to visual assessment of symptoms in %) was 74.67% (Cucumis sativus on day 21). Only slightly lower damage (67.33% on day 21) was observed for Glycine max.
- Plant dry weights: See the table "BIOMASS DRY WEIGHT OF PLANTS AFTER TEST TERMINATION" attached in background material
- Effect data: After application of 975 g a.i./ha for one species tested the phytotoxic effects on biomass were significantly > 20%. After application of 3250 g a.i./ha for three species tested the phytotoxic effects on biomass were significantly > 20%

RESULTS OF CONTROLS
- Number/ percentage of plants showing adverse effects: No adverse effects observed for control plants
- Nature of adverse effects: No adverse effects described.

PB80 EC-NF applied at 975 or 3250 g a.i./ha caused chlorosis in all dicots (Beta vulgaris,Cucumis sativus,Helianthus annuusand Glycinemax.). ForCucumis sativusstunted growth was observed for both test rates at the last evaluation as well. After application of 975 g a.i./ha for one species tested the phytotoxic effects on biomass were significantly > 20%. After application of 3250 g a.i./ha for three species tested the phytotoxic effects on biomass were significantly > 20%.

ER50

> 3250

Validity criteria fulfilled:

yes

Remarks:

in agreement with the OECD 208 and according to EPA OPPTS 850.4150 (vegetative vigor test)

Conclusions:

The following validity criteria were defined:
- The survival of the plants in the control is at least 90% at the end of the test (source OECD 208)
- A coefficient of variation of maximum 20 % for plants biomass in the control (source OECD 208) for “Allium cepa” where this would not be guaranteed) (source: verbal information of German authorities)
- No phytotoxicity in the control (source OECD 208)

Validity criteria were fulfilled in all cases except for the coefficient of variation for Allium cepa and Beta vulgaris, nevertheless the study was classified valid. See the validity criteria summarized in the tables "VALIDITY CRITERIA" atttached in background material.

Description of key information

One study followed OECD guideline 208 and is considered a short-term study.

The other study followed EPA OPPTS 850.4100 (Terrestrial Plant Toxicity Tier I (seedling emergence)) and EPA OPPTS 850.4225 (Seedling Emergence Tier II) and is considered a long term study.

Key value for chemical safety assessment

Short-term EC50 or LC50 for terrestrial plants:

3 250

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

6 725

Additional information

Values above are given in g/ha.

The short-term EC50 is 3250 g/ha.

In the long term experiment, the percent reduction of percent emergence, shoot length and shoot dry weight for ten species was < 25% at the application rate of 6725.08 g/ha.