ethyl-2-[(ethoxycarbonyl)amino]-4-methyl-5-(4-nitrophenyl)thiophene-3-carboxylate

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2022

Report date:

2022

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

yes

Remarks:

The reported results are based on calculated concentration data which are gained out of a non-validated HPLC method.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Ethyl 2-[(ethoxycarbonyl)amino]-4-methyl-5-(4-nitrophenyl)thiophene-3-carboxylate

Cas Number:

308831-93-8

Molecular formula:

C17H18N2O6S

IUPAC Name:

Ethyl 2-[(ethoxycarbonyl)amino]-4-methyl-5-(4-nitrophenyl)thiophene-3-carboxylate

Test material form:

solid: particulate/powder

Sampling and analysis

Analytical monitoring:

no

Remarks:

The reported results are based on calculated concentration data which are gained out of a non-validated HPLC method.

Test solutions

Vehicle:

yes

Remarks:

OECD medium

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

Test species:
Pseudokirchneriella subcapitata (Korshikov) F.Hindák (formerly known as Selenastrum capricornutum and Raphidocelis subcapitata)
Source:
Culture Collection of Algae and Protozoa, Scottish Marine Institute (www.ccap.ac.uk)
Batch:
CCAP 278/4

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

22 ± 2 °C

pH:

6.638 - 7.077 (pH at the beginning of the test)
7.888 - 8.267 (Average pH at the end of the test)

Nominal and measured concentrations:

The evaluation of the toxic effects of the test item was based on the following measured and calculated concentrations: 0.000005; 0.000010; 0.000015; 0.000020 and 0.000030 mg/L.

Details on test conditions:

Three replicates were prepared at every test and six at the control level. The vessels contained 75 ml test media.
The test vessels were closed with aluminium foil and kept in the Binder KBW 400 incubator. The test was maintained under static conditions for a period of 72 hours. The temperature during the test remained in the 22 ± 2 °C range. The temperature data were harvested by Extech SD200 datalogger (Appendix 6). The vessels were shaken and illuminated continuously in the incubator. The vessels were placed randomly into the incubator and were repositioned daily after sampling.

Reference substance (positive control):

not required

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0 mg/L

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

0 mg/L

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0 mg/L

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0 mg/L

Basis for effect:

biomass

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

0 mg/L

Basis for effect:

biomass

Effect concentrations 6

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0 mg/L

Basis for effect:

biomass

Effect concentrations 7

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 0 mg/L

Basis for effect:

biomass

Effect concentrations 8

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 0 mg/L

Basis for effect:

growth rate

Effect concentrations 9

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 0 mg/L

Basis for effect:

biomass

Effect concentrations 10

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 0 mg/L

Basis for effect:

growth rate

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

According to the test results ENTC has no toxic effect on alga growth rate even at its saturated concentration (0.00 mg/L, NOEC≥ saturated concentration (0.00003 mg/L)).
According to the Council Regulation (EC) 440/2008 ENTC is not hazardous to the aquatic environment [72 h EC50 (for algae or other aquatic plants) > saturated concentration of ENTC (0.00003 mg/L).