potassium titanium oxide (K2Ti6O13)

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:

2019-2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 208 (Terrestrial Plants, Growth Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Potasum hexatitanate, potassium titanium oxide
Batch n. MA-95150
Solid, light-yellow powder

Analytical monitoring:

not required

Remarks:

The analytical monitoring of the test item was not required, according to the test guideline.

Vehicle:

yes

Remarks:

fine quartz sand (as dispersant)

Details on preparation and application of test substrate:

Summary
The test item was mixed with fine quartz sand (as dispersant) and then applied with this mixture into soil. Application was done with laboratory mixer. The seeds were afterwards sown in the treated soil.
Untreated control was obtained with the same amount of untreated quartz sand as in the test item treated groups and added to the soil.
Details
35000 mg Potassium titanium oxide was weighed using an analytical balance. The test item was mixed with fine quartz sand (1306 g) by a blender for around 5 minutes and was then applied with this mixture to the soil (35.0 kg). The test item treated fine quartz sand was mixed with the soil by using a laboratory mixer for around 5 minutes. The amount of quartz sand depended on the water content of the used charge of soil and was the same in all treatment groups (37.3 g quartz sand per kg soil). For the control the same amount of untreated quartz sand per kg soil as in the test item treated group was added to the soil. The application was done with a laboratory mixer. The soil for each treatment was treated in two batches and then split into the replicates (pots). 1000 mg test item/kg soil dry weight (nominal) was applied.

Species:

Brassica napus

Plant group:

Dicotyledonae (dicots)

Species:

Glycine max (G. soja)

Plant group:

Dicotyledonae (dicots)

Species:

Lycopersicon esculentum

Plant group:

Dicotyledonae (dicots)

Species:

Cucumis sativus

Plant group:

Dicotyledonae (dicots)

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Species:

Allium cepa

Plant group:

Monocotyledonae (monocots)

Test type:

seedling emergence and seedling growth test

Study type:

laboratory study

Substrate type:

natural soil

Limit test:

yes

Total exposure duration:

21 d

Remarks:

A preliminary range finder test was performed, that showed no effects on fresh weight. Therefore, the limit test was choosen.

Test temperature:

22 °C ± 10 °C

Details on test conditions:

TEST SYSTEM
- Test container (type, material, size): commercial plastic flower pots (15 cm diameter)
- No. of seeds per container:

Species Seeds per Pot Replicates (No of pots) Tested Seeds per Treatment Group
Brassica napus 3 7 21
Glycine max 2 10 20
Solanum lycopersicum 2 10 20
Cucumis sativus 2 10 20
Avena sativa 5 4 20
Allium cepa 5 4 20


SOURCE AND PROPERTIES OF SUBSTRATE
The soil was steam sterilized, analysed and delivered by the Landwirtschaftliche Untersuchungs- und Forschungsanstalt (LUFA) Speyer: LUFA 2.3 (USDA: sandy loam), all particles =< 0.2 cm, organic carbon maximum 1.5%. No pesticide treatment was performed in the year of sampling and 2 previous years.

GROWTH CONDITIONS
- Photoperiod: 16 hrs light, 8 hrs dark
- Light intensity: minimum 200 microE/m2/s

VEHICLE CONTROL PERFORMED: yes

TEST CONCENTRATIONS
- Spacing factor for test concentrations: limit test, 1000 mg/kg soil dw

RANGE FINDING STUDY

---------------------------------------------------------------------------------------------------------------------------------

Species Pot Treatment group (mg test item/kg dry soil)
Brassica napus control 0,10 1,00 10,0 100 1000
1 12,293 11,119 10,084 12,015 12,195 10,295
2 11,788 11,261 10,624 11,940 12,537 12,605
3 11,220 12,311 11,529 11,411 11,202 9,035
Mean [g] 11,767 11,564 10,746 11,789 11,978 10,645
Standard Deviation ± 0,54 ± 0,65 ± 0,73 ± 0,33 ± 0,69 ± 1,81
% of Control 98,3 91,3 100,2 101,8 90,5
Effect [%] -1,7 -8,7 0,2 1,8 -9,5

---------------------------------------------------------------------------------------------------------------------------------

Species Pot Treatment group (mL oder mg test item oder a.i./ha oder kg)
Glycine max control 0,10 1,00 10,0 100 1000
1 7,849 9,246 10,676 9,523 8,492 10,177
2 8,435 11,297 7,349 9,314 8,079 10,450
3 9,073 12,125 8,818 12,737 9,982 9,509
Mean [g] 8,452 10,889 8,948 10,525 8,851 10,045
Standard Deviation ± 0,61 ± 1,48 ± 1,67 ± 1,92 ± 1,00 ± 0,48
% of Control 128,8 105,9 124,5 104,7 118,8
Effect [%] 28,8 5,9 24,5 4,7 18,8

---------------------------------------------------------------------------------------------------------------------------------

Species Pot Treatment group (mL oder mg test item oder a.i./ha oder kg)
Solanum lycopersicum control 0,10 1,00 10,0 100 1000
1 1,418 1,835 2,005 2,404 1,630 2,024
2 1,968 1,880 1,881 1,747 1,874 1,078
3 2,020 1,723 1,961 1,924 1,824 2,286
Mean [g] 1,802 1,813 1,949 2,025 1,776 1,796
Standard Deviation ± 0,33 ± 0,08 ± 0,06 ± 0,34 ± 0,13 ± 0,64
% of Control 100,6 108,2 112,4 98,6 99,7
Effect [%] 0,6 8,2 12,4 -1,4 -0,3

---------------------------------------------------------------------------------------------------------------------------------

Species Pot Treatment group (mL oder mg test item oder a.i./ha oder kg)
Cucumus sativus control 0,10 1,00 10,0 100 1000
1 7,472 5,297 7,032 4,429 6,568 5,566
2 5,553 7,537 5,248 6,551 6,666 6,534
3 5,727 7,238 7,360 6,448 5,645 4,894
Mean [g] 6,251 6,691 6,547 5,809 6,293 5,665
Standard Deviation ± 1,06 ± 1,22 ± 1,14 ± 1,20 ± 0,56 ± 0,82
% of Control 107,0 104,7 92,9 100,7 90,6
Effect [%] 7,0 4,7 -7,1 0,7 -9,4

---------------------------------------------------------------------------------------------------------------------------------

Species Pot Treatment group (mL oder mg test item oder a.i./ha oder kg)
Avena sativa control 0,10 1,00 10,0 100 1000
1 3,414 3,544 4,771 4,683 4,721 5,725
2 3,930 3,734 4,556 4,313 4,369 4,293
3 4,359 3,951 5,023 5,041 4,628 4,315
Mean [g] 3,901 3,743 4,783 4,679 4,573 4,778
Standard Deviation ± 0,47 ± 0,20 ± 0,23 ± 0,36 ± 0,18 ± 0,82
% of Control 95,9 122,6 119,9 117,2 122,5
Effect [%] -4,1 22,6 19,9 17,2 22,5

---------------------------------------------------------------------------------------------------------------------------------

Species Pot Treatment group (mL oder mg test item oder a.i./ha oder kg)
Allium cepa control 0,10 1,00 10,0 100 1000
1 0,579 0,701 0,577 0,499 0,502 0,673
2 0,679 0,787 0,635 0,621 0,606 0,712
3 0,621 0,672 0,683 0,444 0,736 0,688
Mean [g] 0,626 0,720 0,632 0,521 0,615 0,691
Standard Deviation ± 0,05 ± 0,06 ± 0,05 ± 0,09 ± 0,12 ± 0,02
% of Control 115,0 100,9 83,2 98,1 110,3
Effect [%] 15,0 0,9 -16,8 -1,9 10,3

---------------------------------------------------------------------------------------------------------------------------------

Nominal and measured concentrations:

1000 mg/kg soil dw

Key result

Species:

Brassica napus

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Key result

Species:

Glycine max (G. soja)

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Key result

Species:

Lycopersicon esculentum

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Key result

Species:

Cucumis sativus

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Key result

Species:

Avena sativa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Key result

Species:

Allium cepa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Key result

Species:

Allium cepa

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:

phytotoxicity

Key result

Species:

Brassica napus

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: mortality

Key result

Species:

Glycine max (G. soja)

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: mortality

Key result

Species:

Lycopersicon 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: mortality

Key result

Species:

Cucumis sativus

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: mortality

Key result

Species:

Avena sativa

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: mortality

Key result

Species:

Allium cepa

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: mortality

Details on results:

At 1000 mg/kg soil dw:
- seedling emergence was >= 85% in all tested species.
- mortality was 0% in all tested species

At 1000 mg/kg soil dw fresh weigth effects were observed as follows:
- Brassica napus -4.2%
- Glycine max -3.3%
- Lycopersicon esculentum -19.5%
- Cucumis sativus -13.7%
- Avena sativa +20.1%
- Allium cepa -8.5%

Validity criteria

The validity criteria were met.

- the Emergence Rate of the Control Seeds was 90% -100%.

- the Mean Survival of Emerged Control Seedlings was 95% - 100%.

- for Growth and Morphology of the Control Seedlings, the control seedlings exhibited no visible phytotoxic effects and the plants exhibited only normal variation in growth and morphology for that particular species; validity criterion was met. (On account of the mortality in the control for Allium cepa (5%) the phytotoxicity value for this replicate is not “0”, but no further phytotoxicity was observed.)

- the following environmental conditions apply to all plant tested:

----- Test Environment: The test was performed in a growth chamber under controlled conditions.

----- Light Regime: 16 h light : 8 h dark

----- Temperature: measurement was done during the entire study with one mean measuring point every 15 minutes (minimum 15.2°C, maximum 24.8°C, mean 20.6°C)

----- Relative Humidity: measurement was done during the entire study with one mean measuring point every 15 minutes (minimum 44%, maximum 76%, mean 61%)

----- Light Intensity: measurement was done once a week during the entire study with 5 different measuring points for each species (minimum 200 microE/m2/s, maximum 370 microE&m2/s, mean 255 microE/m2/s).

- Moisture Check and Irrigation: A spot check on soil moisture was carried out daily. Bottom watering (through saucers) was done where necessary. Water was given in order to assure optimal water supply of the plants.

Tabular results

Detailed data are provided in attachment.

Validity criteria fulfilled:

yes

Conclusions:

The study did not show adverse effects of the substance on terrestrial plants.

Description of key information

No significant effects were observed. NOEC values are >= 1000 mg/kg soil dw.