Di(benzothiazol-2-yl) disulphide

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:

19 January 2017 - 09 February 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 208 (Terrestrial Plants, Growth Test)

GLP compliance:

yes (incl. QA statement)

Details on sampling:

On day 7 and on day 14 to 16 after 50% emergence in the control, seedlings were counted, evaluated visually, and harvested to determine shoot length and shoot fresh weight.

Vehicle:

no

Details on preparation and application of test substrate:

Defined amounts (corresponding to the nominal concentrations given in Table 4) of ground
test item were weighed out for each treatment separately and ground with fine quartz sand
for 3 minutes. Afterwards, the test item amended quartz sand was thoroughly mixed for 10
minutes into the 16.2 kg by using a mixer in order to homogeneously distribute the test item
in the soil. The concentration of sand added to the soil was 1% (i.e. 10 g/kg soil). The control
soil received sand which had not been treated with the test item.

Species:

Allium cepa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

Common name: onion
Family: Amaryllidaceae
Cultivar: Stuttgarter Riesen
Lot no.: 4333216
Source of supply: Enza Zaden

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

Common name: oat
Family: Poaceae
Cultivar: Canyon
Lot no.: n.a.
Source of supply: Nordsaat

Species:

Brassica napus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Common name: rape
Family: Brassicaceae
Cultivar: Akela
Lot no.: n.a.
Source of supply: Freudenberger

Species:

Cucumis sativus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Common name: cucumber
Family: Cucurbitaceae
Cultivar: Delikatess
Lot no.: 4291508
Source of supply: Enza Zaden

Species:

Pisum sativum

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Common name: pea
Family: Fabaceae
Cultivar: Rondo
Lot no.: 117024NV
Source of supply: Enza Zaden

Species:

other: Solanum lycopersicum

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Common name: tomato
Family: Solanaceae
Cultivar: Hellfrucht
Lot no.: 4317738
Source of supply: Enza Zaden

Test type:

seedling emergence and seedling growth test

Study type:

laboratory study

Substrate type:

natural soil

Remarks:

LUFA Soil Type 2.3 (Landwirtschaftliche Untersuchungs- und Forschungsanstalt (LUFA), D-67346 Speyer, Germany)

Limit test:

no

Total exposure duration:

14 d

Remarks:

Duration of the test was either 14 days (A. cepa, A. sativa, P. sativum), or 15 days (C. sativus, S. lycopersicum), or 16 days (B. napus), following seedling emergence of at least 50% in the control soil of the respective test species.

Test temperature:

Air temperature:
14.7°C min. - 22.3°C max. (mean: 19.8°C)
20.3°C min. - 26.5°C max. (mean: 24.3°C) (B. Napus only)

Moisture:

Rel. air humidity [%]:
30.4 min. - 49.4 max. (mean: 37.1)
14.8 min. - 48.6 max. (mean: 23.6) (B. napus only)

Details on test conditions:

Lighting [μE m-2 s-1]:
213 min. - 352 max.
203 min. - 268 max. (B.Napus only)
Photo period = 16 h

Nominal and measured concentrations:

95.3, 171, 309, 556, 1000 mg/kg soil dw

Reference substance (positive control):

no

Species:

other: all test species

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:

seedling emergence

Species:

other: all test species

Duration:

14 d

Dose descriptor:

LOEC

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Species:

other: all test species

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:

growth

Remarks:

shoot length

Species:

other: all test species

Duration:

14 d

Dose descriptor:

LOEC

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

shoot length

Species:

other: all test species

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:

growth

Remarks:

shoot fresh weight

Species:

other: all test species

Duration:

14 d

Dose descriptor:

LOEC

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

shoot fresh weight

Details on results:

Duration of the test was either 14 days (A. cepa, A. sativa, P. sativum), or 15 days (C. sativus, S. lycopersicum), or 16 days (B. napus), following seedling emergence of at least 50% in the control soil of the respective test species.

The effects of the test item RUBATOR MBTS on the emergence and growth of seedlings were tested in the laboratory.

The test item had no statistically significant adverse effect on either seedling emergence, seedling survival, shoot length or shoot fresh weight of any of the six test species at concentrations up to and including 1000 mg/kg soil dry weight, which was the highest tested concentration.

The NOEC and LOEC were therefore determined to be ≥1000 mg/kg soil dw and > 1000 mg/kg soil dw, respectively.

Due to the lack of adverse effects effective concentrations could not be calculated and are assumed to be higher than 1000 mg/kg dw.

Validity criteria fulfilled:

yes

Conclusions:

Di(benzothiazol-2-yl) disulphide showed a NOEC of >= 1000 mg/kg dw and a LOEC of >1000 mg/kg dw for all test species on the effcet basis of emergence, survival and growth (shoot length and shoot fresh weight).

Executive summary:

The long-term effects of di(benzothiazol-2-yl) disulphide on terrestrial plant seedling emergence and seedling growth was investigated according to the OECD guideline 208. The test species were

two monocotyledonous species, Avena sativa (oat) and Allium cepa (onion), as well as four dicotyledonous species, Brassica napus (rape), Cucumis sativus (cucumber), Pisum sativum (pea) and Solanum lycopersicum (tomato). Duration of the test was either 14 days (A. cepa, A. sativa, P. sativum), or 15 days (C. sativus, S. lycopersicum), or 16 days (B. napus). Taking into account the emergence, survival and growth as basis of effect, the test substance showed a NOEC of >= 1000 mg/kg dw and a LOEC of >1000 mg/kg dw for all test species (ECT 2017).

Therefore, it can be concluded that di(benzothiazol-2-yl) disulphide has no chronic effects to terrestrial plants.

Description of key information

The long-term effects of di(benzothiazol-2-yl) disulphide on terrestrial plant seedling emergence and seedling growth was investigated according to the OECD guideline 208. The test species were

two monocotyledonous species, Avena sativa (oat) and Allium cepa (onion), as well as four dicotyledonous species, Brassica napus (rape), Cucumis sativus (cucumber), Pisum sativum (pea) and Solanum lycopersicum (tomato). Duration of the test was either 14 days (A. cepa, A. sativa, P. sativum), or 15 days (C. sativus, S. lycopersicum), or 16 days (B. napus). Taking into account the emergence, survival and growth as basis of effect, the test substance showed a NOEC of >= 1000 mg/kg dw and a LOEC of >1000 mg/kg dw for all test species (ECT 2017).

Therefore, it can be concluded that di(benzothiazol-2-yl) disulphide has no chronic effects to terrestrial plants.