Tetrakis(phenylmethyl)thioperoxydi(carbothioamide)

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Guideline study performed in compliance with GLP, available as unpublished report, no restrictions, fully adequate for assessment.

Qualifier:

according to guideline

Guideline:

other: Directive 84/449/EEC, Part C, C.2

Deviations:

no

Principles of method if other than guideline:

Directive 84/449/EEC was replaced by Directive 92/69/EEC and REGULATION (EC) No 440/2008
Equivalent to OECD 202

GLP compliance:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): Tetrabenzylthiuramdisulphide (TBeTD)
- Substance type: Mono-constituent substance
- Physical state: White powder
- Stability under test conditions: Semi-static test with renewal after 48 hours. TBzTD is not biodegradable within this period of time.
- Storage condition of test material: 20°C
- Analytical purity: > 95%, technically pure
- Purity test date: > 95%, technically pure
- Lot/batch No.: 880526/5 (OR2)

Analytical monitoring:

no

Vehicle:

yes

Details on test solutions:

Identity and concentration of auxiliary solvent for dispersal: Aceton was used for the dispersion of the test substance in water at a concentration of equal or less than 1 ml per 1000 ml water.

TBzTD has got an extremely low solubility in water in the order of 10 to 100 µg/l. The fish were exposed to oversaturated dispersions of TBzTD in the test medium at all concentrations tested. TBzTD particles stack to the water surface of the test medium and settled on the bottom of the test vessel. The concentration of TBzTD in the test medium remained constant.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Source: The test animals were produced by a brood stock of 3 weeks old.
- Age at study initiation (mean and range, SD): They were between 6 and 24 hours at the start of the test.
- Method of breeding: Described in Standard Operation Procedure SOP CRL T2 (Akzo Research Laboratories Arnhem, department CRL)
- Feeding during test: No

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

27 mg Ca/l, 17 mg Mg/l, 7.7° dH

Test temperature:

20.0 to 20.5°C

pH:

8.2

Dissolved oxygen:

8.9 to 9.1 mg/l

Salinity:

-

Nominal and measured concentrations:

10 mg/l, 100 mg/l, nominal.

TBzTD has got an extremely low solubility in water in the order of 10 to 100 µg/l. The fish were exposed to oversaturated dispersions of TBzTD in the test medium at all concentrations tested. TBzTD particles stack to the water surface of the test medium and settled on the bottom of the test vessel. The concentration of TBzTD in the test medium remained constant.

Details on test conditions:

TEST SYSTEM
- Test vessel: 400 ml glass beakers
- Type: Open
- Material, size, headspace, fill volume: 250 ml
- Aeration: No
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate): After 48h
- No. of organisms per vessel: 5 animals
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 2 x 4
- Biomass loading rate: 0.6 g biomass/l

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The dilution water was a natural water from a turtle aquarium, which was also used for the cultivation of Daphnia. This aquarium was purified by a biological filtration system (including a mechanical filter, an aerobic sprinkling filter and an anaerobic nitrate removal (Minireef System)
- Culture medium different from test medium: No

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 12 hours per day
- Light intensity: Artificial light

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10
- Range finding study: Yes
- Test concentrations: 10 and 100 mg/l
- Results used to determine the conditions for the definitive study: In the range-finding test, Daphnia were not immobilized in an oversaturated dispersion of 10 mg TBzTD per litre.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

ca. 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: At 100 mg/l animals were totally covered with TBzTD; TBzTD visible in their guts

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

ca. 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: At 100 mg/l animals were totally covered with TBzTD; TBzTD visible in their guts

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities:
- Observations on body length and weight:
- Other biological observations: None
- Mortality of control: No
- Other adverse effects control: No
- Abnormal responses:
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: In the range-finding test, Daphnia were not immobilized in a dispersion of 10 mg/l during 2 days (a concentration of 10 mg/l is over-saturated and cause TBzTD to precipitate). In the definitive test a dispersion of 100 mg/l was included (containing 1 ml acetone/l as a vehicle). At this concentration, more than 50% of the test animals appeared affected. Microscopic observations indicated that TBzTD particles were stuck on the carapace, antennae and branchiopods of the test animals. Moreover, their gut was filled with white particles. Therefore it is assumed that the effect was caused by physical hindrance by TBzTD particles and that this was not a toxic effect.
- Effect concentrations exceeding solubility of substance in test medium: TBzTD has got an extremely low solubility in water in the order of 10 to 100 µg /l. The daphnia were exposed to oversaturated dispersions of TBzTD in the test medium at all concentrations tested. TBzTD particles settled on the bottom of the test vessel. The concentration of TBzTD in the test medium remained constant.

pH and oxygen concentrations during the test

Concentration (nominal) / mg/l	Test duration / hours
	0 (fresh)	48 (old)	48
	pH		O2 / mg/l
Control (a)	8.1	8.2	8.9
Control (b)	8.1	8.2	9.0
Control (c)	8.2	8.2	9.1
Control (d)	8.1	8.1	8.9
Solvent control 0.1 (a)	8.2	8.2	9.1
Solvent control 0.1 (b)	8.1	8.2	9.0
Solvent control 0.1 (c)	8.1	8.2	9.0
Solvent control 0.1 (d)	8.1	8.2	9.0
Solvent control 1.0 (a)	8.1	8.2	9.0
Solvent control 1.0 (b)	8.1	8.2	9.0
Solvent control 1.0 (c)	8.1	8.1	8.9
Solvent control 1.0 (d)	8.1	8.2	8.9
10 (a)	8.2	8.2	9.0
10 (b)	8.2	8.2	8.9
10 (c)	8.2	8.2	8.9
10 (d)	8.2	8.2	8.9
100 (a)	8.1	8.1	8.9
100 (b)	8.1	8.2	9.0
100 (c)	8.1	8.2	8.9
100 (d)	8.1	8.2	8.9
Temperature / °C	20.3	20.7

Observation on the animals (range finding test)

TBzTD concentration (nominal) / mg/l	Test duration / hours
	0	24	48
	Number of animals surviving
Control	5	5	5
0.01	5	5	5
0.1	5	5*	5
1	5	5**	5
10	5	5	5
Temperature / °C	* 1 animal trapped at the surface
	** 1 moves with difficulty; totally covered with TBzTD

Observation on the animals (definitive test)

 

TBzTD concentration (nominal) / mg/l	Test duration / hours
	0	24	48
	Number of animals surviving
Control (a)	5	5	5
Control (b)	5	5	5
Control (c)	5	5	5
Control (d)	5	5	5
Solvent control 0.1 (a)	5	5	5
Solvent control 0.1 (b)	5	5	5
Solvent control 0.1 (c)	5	5	5
Solvent control 0.1 (d)	5	5	5
Solvent control 1.0 (a)	5	5	5
Solvent control 1.0 (b)	5	5	5
Solvent control 1.0 (c)	5	5	5
Solvent control 1.0 (d)	5	5	5
10 (a)	5	5	5
10 (b)	5	5	5
10 (c)	5	5	5
10 (d)	5	5	5
100 (a)	5	2	2
100 (b)	5	3	2
100 (c)	5	3	1
100 (d)	5	4*	2
Temperature / °C	* 1 animal disappeared

Conclusions:

The acute toxicity of tetrakis(phenylmethyl)thioperoxydi(carbothioamide) (TBzTD) was carried out under semi-static conditions according to a method equivalent to OECD 202 (Daphnia sp. acute immobilization test) with Daphnia magna.
A NOEC of 10 mg/l was established. The LC50 of 100 mg/l based on immobility appears to be caused by mechanical obstruction of biological function of Daphnia rather than toxic effects.

Executive summary:

The acute toxicity of tetrakis(phenylmethyl)thioperoxydi(carbothioamide) (TBzTD) was tested out under static conditions and with nominal concentrations of 10 and 100 mg/l according to the Directive 84/449/EEC part C: Methods for the determination of ecotoxicity, C.2. Daphnia sp. acute immobilization test which is equivalent to OECD 202 (Daphnia sp. acute immobilization test). Due to the extremely low solubility of TBzTD a dispersion in water was formed at all test concentrations.

 

The daphnia stayed mobile in a dispersion of 10 mg TBzTD/l (containing 0.1 ml acetone/l as a vehicle) during 2 days and showed no deviations in behavior or appearance. In a dispersion of 100 mg TBzTD/l (containing 1 ml acetone/l as a vehicle) about 50% of the test animals appeared affected at 24 and 48 hours. Microscopic observations indicated that TBzTD particles were stuck on the carapace, antennae and branchiopods of the test animals. Moreover, their gut was filled with white particles. Therefore, it is assumed that the immobilization was caused by a physical hindrance by TBzTD particles rather than by a toxic effect.

 

Based on these results a NOEC of 10 mg/l was established. The LC50 of 100 mg/l based on immobility appears to be caused by mechanical obstruction of biological function of Daphnia rather than toxic effects.

Description of key information

The acute toxicity of tetrakis(phenylmethyl)thioperoxydi(carbothioamide) (TBzTD) was carried out under semi-static conditions according to a method equivalent to OECD 202 (Daphnia sp. acute immobilization test) with Daphnia magna. A NOEC of 10 mg/l was established. The LC50 of 100 mg/l based on immobility appears to be caused by mechanical obstruction of biological function of Daphnia rather than toxic effects.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

The acute toxicity of tetrakis(phenylmethyl)thioperoxydi(carbothioamide) (TBzTD) was tested out under static conditions and with nominal concentrations of 10 and 100 mg/l according to the Directive 84/449/EEC part C: Methods for the determination of ecotoxicity, C.2. Daphnia sp. acute immobilization test which is equivalent to OECD 202 (Daphnia sp. acute immobilization test). Due to the extremely low solubility of TBzTD a dispersion in water was formed at all test concentrations.

The daphnia stayed mobile in a dispersion of 10 mg TBzTD/l (containing 0.1 ml acetone/l as a vehicle) during 2 days and showed no deviations in behavior or appearance. In a dispersion of 100 mg TBzTD/l (containing 1 ml acetone/l as a vehicle) about 50% of the test animals appeared affected at 24 and 48 hours. Microscopic observations indicated that TBzTD particles were stuck on the carapace, antennae and branchiopods of the test animals. Moreover, their gut was filled with white particles. Therefore, it is assumed that the immobilization was caused by a physical hindrance by TBzTD particles rather than by a toxic effect.

Based on these results a NOEC of 10 mg/l was established. The LC50 of 100 mg/l based on immobility appears to be caused by mechanical obstruction of biological function of Daphnia rather than toxic effects.