ethyl 2-amino-4-methyl-5-(4-nitrophenyl)-3-thiophenecarboxylate

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-amino-4-methyl-5-(4-nitrophenyl)thiophene-3-carboxylate

EC Number:

839-928-3

Cas Number:

174072-89-0

Molecular formula:

C14H14N2O4S

IUPAC Name:

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

Test material form:

solid: crystalline

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:

7.056 - 7.080 pH (at the beginning of the test)
6.747 - 7.474 pH (average pH at the end of the test)

Nominal and measured concentrations:

0.00198; 0.00396 0.00595; 0.00793 and 0.01189 mg/L (nominal)

Details on test conditions:

Preparation of test vessels:
Three replicates were prepared at every test and six at the control level. The vessels contained 75 ml test media.
Test procedure
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.
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.:

0.016 mg/L

Nominal / measured:

nominal

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC20

Basis for effect:

growth rate

Remarks on result:

not determinable

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Basis for effect:

growth rate

Remarks on result:

not determinable

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.009 mg/L

Nominal / measured:

nominal

Basis for effect:

biomass

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

0.011 mg/L

Nominal / measured:

nominal

Basis for effect:

biomass

Effect concentrations 6

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.016 mg/L

Nominal / measured:

nominal

Basis for effect:

biomass

Effect concentrations 7

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.008 mg/L

Nominal / measured:

nominal

Basis for effect:

growth rate

Effect concentrations 8

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

0.012 mg/L

Nominal / measured:

nominal

Basis for effect:

growth rate

Effect concentrations 9

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.008 mg/L

Nominal / measured:

nominal

Basis for effect:

biomass

Effect concentrations 10

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

0.012 mg/L

Nominal / measured:

nominal

Basis for effect:

biomass

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

According to the test results NTC did not cause 50% inhibition in the specific growth rate even at its saturated concentration (ErC50 for specific growth rate > 0.01189 mg/L). According to the Council Regulation (EC) 440/ NTC is not hazardous to the aquatic environment [72 h EC50 (for algae or other aquatic plants) > saturated concentration of NTC (0.01189 mg/L)]