2-(3-oxobenzo[b]thien-2(3H)-ylidene)benzo[b]thiophene-3(2H)-one

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

Justification for type of information:

Experimental result performed using standard methods of analysis

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Qualifier:

according to guideline

Guideline:

other: Directive 92/69/EC Method C.2 (1992)

Principles of method if other than guideline:

To evaluate acute Immobilisation Test (Static, 48 h) to Daphnia magna

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

IUPAC: 2-(3-oxobenzo[b]thien-2(3H)-ylidene)benzo[b]thiophene-3(2H)-one
Molecular Formula: C16H8O2S2
Molecular Weight: 296.369 g/mol
Smiles:O=C1c2c(S\C1=C1/Sc3c(cccc3)C1=O)cccc2
InChI:1S/C16H8O2S2/c17-13-9-5-1-3-7-11(9)19-15(13)16-14(18)10-6-2-4-8-12(10)20-16/h1-8H/b16-15-

Analytical monitoring:

yes

Vehicle:

not specified

Details on test solutions:

The solution (100 mg/L test item was weighed out) was prepared with dilution water in brown glass flask one day day prior to application.The stock solution was shaken with 20 rpm for 24 h (rotating shaker 3040, GFL). Undissolved particles were removed by centrifugation (20 min at 3000).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: STRAUS (Clone 5)
- Source: Institut für Wasser-, Boden- und Lufthygiene (WaBoLu)
- Age of parental stock (mean and range, SD): 2 - 24 h old
- Feeding during test: The daphnids were not fed during the study
- Food type: mix of Desmodesmus subspicatus and Chlorella vulgaris
- Amount:106 cells/mL
- Frequency: At least 5 per week ad libitum
-Acclimatization: 2 h before test start

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

274 [mg CaCO3/L]

Test temperature:

20.8 °C

pH:

7.98

Dissolved oxygen:

7.98 mg/l

Conductivity:

649 μS/cm

Nominal and measured concentrations:

0 , 1, 10 , 100 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers (5 cm ID x 8 cm H
- fill volume: 50 mL volume
- No. of organisms per vessel: 20 animals
- No. of vessels per concentration (replicates): 4
-Illumination : Illumination Diffuse light, illumination range max. 20 μEm-2 s-1
-Photoperiod :16/8 h light/dark cycle

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: no biologically significant effect was determined.

Details on results:

no biologically significant effect was determined.

Results with reference substance (positive control):

EC50 : 1.80 (CI 1.74 - 1.85)
EC100 : 2.87

Reported statistics and error estimates:

All data were computer generated and rounded for presentation from the full derived data. Consequently, if calculated manually based on the given data minor variations may occur from these figures.
Calculations were carried out using software: GraphPad Prism4 (2005), GRAPHPAD SOFTWARE, INC

Table 1:   Percentage Number of Daphnia Incapable of Swimming after 24 and 48 h of Exposure (n = 20)

				24 h							48 h
			Replicates							Replicates
	1.	2.		3.		4.	MV	1.	2.		3.		4.	MV
Saturated solution^#	0	0		0		0	0	0	0		0		0	0
Control	0	0		0		0	0	0	0		0		0	0

Table 2:   Immobilisation Rates of the Preliminary Test in [%](n = 20)

			IMMOBILISATION [%]
Dilution out of the		24 h			48 h
saturated solution		Replicates			Replicates
	1	2	MV	1	2	MV
1:1	0	0	0	0	0	0
1:10	0	0	0	0	0	0
1:100	0	0	0	0	0	0
Control	0	0	0	0	0	0

Table 3:   Percentage Number of Daphnia Incapable of Swimming after 24 and 48 h of Exposure(n = 20)

				24 h							48 h
			Replicates							Replicates
	1.	2.		3.		4.	MV	1.	2.		3.		4.	MV
Saturated solution^#	0	0		0		0	0	0	0		0		0	0
Control	0	0		0		0	0	0	0		0		0	0

Validity criteria fulfilled:

yes

Conclusions:

The EC50 value for the test material 2-(3-oxobenzo[b]thien-2(3H)-ylidene)benzo[b]thiophene-3(2H)-one was observed to be >100 mg/l

Executive summary:

In the acute immobilisation test with Daphnia magna (STRAUS) performed as per OECD Guideline 202 (Daphnia sp. Acute Immobilisation test in GLP certified lab . The effect of the of the saturated solution (DOC 3.5 mg/L) of the test item 2-(3-oxobenzo[b]thien -2(3H) -ylidene)benzo[b]thiophene-3(2H)-one was determined according to OECD 202 (2004) and Directive 92/69/EC Method The limit test was conducted under static conditions over 48 h . 20 test organisms were exposed to the saturated solution and the control. A reference test was carried out with potassium dichromate to determine the toxicity of the reference item.

Daphnia magna STRAUS (Clone 5) was cultured in Elendt M4 modified to a total hardness of 160 to 180 mg CaCO3/L . At least 5 per week ad libitum with a mix of Desmodesmus subspicatus and Chlorella vulgaris, with an alga cell density of > 106cells/mL. The solution (100 mg/L test item was weighed out) was prepared with dilution water in brown glass flask one day day prior to application. The stock solution was shaken with 20 rpm for 24 h (rotating shaker 3040, GFL). Undissolved particles were removed by centrifugation (20 min at 3000). The test was conducted in Glass beakers (5 cm ID x 8 cm H), 50 mL volume were used. 20 animals, divided into 4 parallel samples, each with 5 animals. The daphnids were not fed during the study . A preliminary range finding test was conducted under static conditions. EC10- and EC50-values were only calculated for the reference item by sigmoidal dose-response regression. Calculation of the confidence interval for EC50 were carried out using standard procedures according to CLOPPER and PEARSON (1934). The EC50 value of test material 2-(3-oxobenzo[b]thien-2(3H)-ylidene) benzo[b]thiophene-3(2H)-one after 48h  was observed to be >100 mg/l . There was no biologically significant effect neither in the tested saturated solution nor in the control group. Based on the above observation it can be considered that test material 2-(3-oxobenzo[b]thien-2(3H)-ylidene)benzo[b]thiophene-3(2H)-one is not toxic to aquatic invertebrate and hence, can not be classified as per CLP criteria.

Description of key information

Short term toxicity to aquatic invertebrates:

Short term toxicity study for aquatic invertebrates was summarized in the experimental report as follows:

In the acute immobilisation test with Daphnia magna (STRAUS) performed as per OECD Guideline 202 (Daphnia sp. Acute Immobilisation test in GLP certified lab . The effect of the of the saturated solution (DOC 3.5 mg/L) of the test item 2-(3-oxobenzo[b]thien -2(3H) -ylidene)benzo[b]thiophene-3(2H)-one was determined according to OECD 202 (2004) and Directive 92/69/EC Method The limit test was conducted under static conditions over 48 h . 20 test organisms were exposed to the saturated solution and the control. A reference test was carried out with potassium dichromate to determine the toxicity of the reference item.

Daphnia magna STRAUS (Clone 5) was cultured in Elendt M4 modified to a total hardness of 160 to 180 mg CaCO3/L . At least 5 per week ad libitum with a mix of Desmodesmus subspicatus and Chlorella vulgaris, with an alga cell density of > 106cells/mL. The solution (100 mg/L test item was weighed out) was prepared with dilution water in brown glass flask one day day prior to application. The stock solution was shaken with 20 rpm for 24 h (rotating shaker 3040, GFL). Undissolved particles were removed by centrifugation (20 min at 3000). The test was conducted in Glass beakers (5 cm ID x 8 cm H), 50 mL volume were used. 20 animals, divided into 4 parallel samples, each with 5 animals. The daphnids were not fed during the study . A preliminary range finding test was conducted under static conditions. EC10- and EC50-values were only calculated for the reference item by sigmoidal dose-response regression. Calculation of the confidence interval for EC50 were carried out using standard procedures according to CLOPPER and PEARSON (1934). The EC50 value of test material 2-(3-oxobenzo[b]thien-2(3H)-ylidene) benzo[b]thiophene-3(2H)-one after 48h  was observed to be >100 mg/l . There was no biologically significant effect neither in the tested saturated solution nor in the control group. Based on the above observation it can be considered that test material 2-(3-oxobenzo[b]thien-2(3H)-ylidene)benzo[b]thiophene-3(2H)-one is not toxic to aquatic invertebrate and hence, can not be classified as per CLP criteria.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

Short term toxicity to aquatic invertebrates:

Short term toxicity study for aquatic invertebrates was summarized in the experimental report as follows:

In the acute immobilisation test with Daphnia magna (STRAUS) performed as per OECD Guideline 202 (Daphnia sp. Acute Immobilisation test in GLP certified lab . The effect of the of the saturated solution (DOC 3.5 mg/L) of the test item 2-(3-oxobenzo[b]thien -2(3H) -ylidene)benzo[b]thiophene-3(2H)-one was determined according to OECD 202 (2004) and Directive 92/69/EC Method The limit test was conducted under static conditions over 48 h . 20 test organisms were exposed to the saturated solution and the control. A reference test was carried out with potassium dichromate to determine the toxicity of the reference item.

Daphnia magna STRAUS (Clone 5) was cultured in Elendt M4 modified to a total hardness of 160 to 180 mg CaCO3/L . At least 5 per week ad libitum with a mix of Desmodesmus subspicatus and Chlorella vulgaris, with an alga cell density of > 106cells/mL. The solution (100 mg/L test item was weighed out) was prepared with dilution water in brown glass flask one day day prior to application. The stock solution was shaken with 20 rpm for 24 h (rotating shaker 3040, GFL). Undissolved particles were removed by centrifugation (20 min at 3000). The test was conducted in Glass beakers (5 cm ID x 8 cm H), 50 mL volume were used. 20 animals, divided into 4 parallel samples, each with 5 animals. The daphnids were not fed during the study . A preliminary range finding test was conducted under static conditions. EC10- and EC50-values were only calculated for the reference item by sigmoidal dose-response regression. Calculation of the confidence interval for EC50 were carried out using standard procedures according to CLOPPER and PEARSON (1934). The EC50 value of test material 2-(3-oxobenzo[b]thien-2(3H)-ylidene) benzo[b]thiophene-3(2H)-one after 48h  was observed to be >100 mg/l . There was no biologically significant effect neither in the tested saturated solution nor in the control group. Based on the above observation it can be considered that test material 2-(3-oxobenzo[b]thien-2(3H)-ylidene)benzo[b]thiophene-3(2H)-one is not toxic to aquatic invertebrate and hence, can not be classified as per CLP criteria.